[Federal Register Volume 69, Number 80 (Monday, April 26, 2004)]
[Rules and Regulations]
[Pages 22402-22441]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-9409]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 9 and 799
[OPPT-2003-0006; FRL-7312-2]
RIN 2070-AD42
In Vitro Dermal Absorption Rate Testing of Certain Chemicals of
Interest to the Occupational Safety and Health Administration
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: EPA is promulgating a final rule under the Toxic Substances
Control Act (TSCA) that requires manufacturers (including importers)
and processors of 34 chemicals to conduct in vitro dermal absorption
rate testing. These chemicals are of interest to the Occupational
Safety and Health Administration (OSHA) of the Department of Labor, and
the data obtained under this testing program will be used by OSHA to
evaluate the need for ``skin designations'' for these chemicals. Skin
designations are used by OSHA to alert industrial hygienists,
employers, and workers to the potentially significant contribution to
the overall exposure to certain chemicals which can occur by the
cutaneous route. Thus, skin designations encourage employers to
consider whether changes should be made to processes involving such
chemical substances in order to reduce the potential for systemic
toxicity from dermal absorption of these chemicals. Persons who export
or intend to export any chemical substance included in this final rule
are subject to the export notification requirements in TSCA section
12(b).
DATES: This final rule is effective on May 26, 2004. For purposes of
judicial review, this final rule shall be promulgated at 1 p.m. eastern
daylight/standard time on May 10, 2004.
ADDRESSES: EPA has established a docket for this action under docket
identification (ID) number OPPT-2003-0006. All documents in the docket
are listed in the EDOCKET index at http://www.epa.gov/edocket/.
Although listed in the index, some information is not publicly
available, i.e., Confidential Business Information (CBI) or other
information whose disclosure is restricted by statute. Certain other
material, such as copyrighted material, will not be placed on the
Internet and will be publicly available only in hard copy form.
Publicly available docket materials are available either electronically
in EDOCKET or in hard copy at the Office of Pollution Prevention and
Toxics (OPPT) Docket, EPA Docket Center (EPA/DC), EPA West, Room B102,
1301 Constitution Ave., NW., Washington, DC. The Public Reading Room is
open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding
legal holidays. The EPA Docket Center Reading Room telephone number is
(202) 566-1744, and the telephone number for the OPPT Docket, which is
located in EPA Docket Center, is (202) 566-0280.
FOR FURTHER INFORMATION CONTACT: For general information contact: Colby
Lintner, Regulatory Coordinator, Environmental Assistance Division
(7408M), Office of Pollution Prevention and Toxics, Environmental
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-
0001; telephone number: (202) 554-1404; e-mail address: [email protected].
For technical information contact: Keith Cronin or Catherine Roman,
Chemical Control Division (7405M), Office of Pollution Prevention and
Toxics, Environmental Protection Agency, 1200 Pennsylvania Ave., NW.,
Washington, DC 20460-0001; telephone number: (202) 564-8157 or (202)
564-8172; e-mail address: [email protected] or
[email protected].
SUPPLEMENTARY INFORMATION:
I. General Information
A. Does this Action Apply to Me?
You may be affected by this action if you manufacture (defined by
statute to include import) or process any of the chemical substances
that are listed in Sec. 799.5115(j) of the regulatory text. Any use of
the term ``manufacture'' in this document will encompass ``import,''
unless otherwise stated. In addition, as described in Unit VI., any
person who exports or intends to export any of the chemical substances
in this final rule is subject to the export notification requirements
in 40 CFR part 707, subpart D. Entities that could be subject to the
requirements in this final rule may include, but are not limited to:
Manufacturers (defined by statute to include
importers) of one or more of the 34 subject chemical substances
[[Page 22403]]
(NAICS 325 and 324110), e.g., chemical manufacturing and petroleum
refineries.
Processors of one or more of the 34 subject
chemical substances (NAICS 325 and 324110), e.g., chemical
manufacturing and petroleum refineries.
This listing is not intended to be exhaustive, but rather provides
a guide for readers regarding entities likely to be affected by this
action. Other types of entities not listed in this unit could also be
affected. The North American Industry Classification System (NAICS)
codes have been provided to assist you and others in determining
whether this action might apply to certain entities. To determine
whether you or your business may be affected by this action, you should
carefully examine the applicability provisions in Unit V.E. and consult
the regulatory text at 40 CFR 799.5115(b). If you have any questions
regarding the applicability of this action to a particular entity,
consult one of the technical persons listed under FOR FURTHER
INFORMATION CONTACT.
B. How Can I Access Electronic Copies of this Document and Other
Related Information?
In addition to EDOCKET (http://www.epa.gov/edocket/), you may
access this Federal Register document electronically through the EPA
Internet under the ``Federal Register'' listings at http://www.epa.gov/fedrgstr/. A frequently updated electronic version of 40 CFR part 9 and
part 799 is available on E-CFR Beta Site Two at http://www.gpoaccess.gov/ecfr/.
II. Background
A. What Action is the Agency Taking?
In this action, EPA is promulgating a test rule under TSCA section
4 (15 U.S.C. 2603) which responds to recommendations of the Interagency
Testing Committee (ITC). Under TSCA section 4(e)(1), the ITC is
responsible for recommending chemical substances and mixtures to the
EPA Administrator for priority testing consideration. In September
1991, the ITC received a nomination from OSHA of 658 chemical
substances and mixtures for ITC review. OSHA requested that the ITC
assess the availability of data relevant to dermal absorption for these
chemical substances and mixtures and determine the need for further
testing (Ref. 1). OSHA indicated to the ITC that it needed quantitative
measures of dermal absorption to evaluate the potential hazard of these
chemicals to workers (Ref. 2). These quantitative measures are
expressed as the dermal absorption rate for a particular chemical (Ref.
3, p. 35725). The results of the ITC's review were published in the
Federal Register (Ref. 1, p. 26900 and Ref. 2, pp. 38492-38493).
In the 31\st\, 32\nd\, and 35\th\ ITC Reports to the EPA
Administrator (Refs. 1, 2, and 4), the ITC designated for in vitro
dermal absorption rate testing a total of 83 of the 658 chemical
substances nominated by OSHA. A summary of the process by which the ITC
selected the 83 chemical substances was presented in the proposal to
this action (Ref. 5, p. 31077). The data reviewed by the ITC included
data obtained from TSCA section 8(a) and 8(d) rules (Refs. 6, 7, and 8)
which were promulgated by EPA for the 83 chemical substances included
in the 31\st\, 32\nd\, and 35\th\ ITC Reports (Refs. 1, 2, and 4).
These rules required the reporting to EPA of certain production, use
and exposure-related information, and unpublished health and safety
data concerning the 83 chemical substances.
In reviewing the available data, the ITC determined that the data
for methyl methacrylate, diethyl phthalate, and cyclohexanone would
meet OSHA's data needs for these three chemicals. Accordingly, the ITC
withdrew its designation for these three chemicals: Methyl methacrylate
and diethyl phthalate in the 34\th\ ITC Report (Ref. 3), and
cyclohexanone in the 36\th\ ITC Report (Ref. 9).
Eighty of the chemical substances originally nominated by OSHA are
thus currently designated by the ITC for in vitro dermal absorption
rate testing under TSCA. In the Federal Register notices containing the
31\st\, 32\nd\, and 35\th\ ITC Reports (Refs. 1, 2, and 4), EPA
solicited proposals for TSCA section 4 enforceable consent agreements
(ECAs) for dermal absorption rate testing of the 80 chemical
substances. EPA received no proposals for ECAs for dermal absorption
rate testing in response to these solicitations.
On April 3, 1996, EPA again solicited interested parties to submit
proposals for ECAs (Ref. 10). On June 26, 1996, EPA received a proposal
from the ARCO Chemical Company (ARCO) (Ref. 11) for tert-butyl alcohol.
On March 26, 1998, EPA received a study from ARCO entitled [\14\C]-t-
Butyl Alcohol: Topical Application: Dermal Absorption Study in the Male
Rat (Refs. 12 and 12a.). This study was reviewed and found acceptable
as a means of determining the dermal absorption rate for tert-butyl
alcohol. Accordingly, EPA did not propose testing of tert-butyl
alcohol.
On June 9, 1999, EPA responded to the ITC's designation of the
remaining 79 chemicals by issuing a proposed test rule under TSCA
section 4 (Ref. 5) which would require that 47 of these chemical
substances be tested with respect to in vitro dermal absorption rate.
The Agency selected the 47 chemicals for testing because, at the time
of the proposal, EPA believed that their production volumes were the
highest among the 80 chemicals designated by the ITC. At the time of
the proposed rule, the most current information available to EPA
indicated that each of the 47 chemicals was produced in ``substantial
quantities,'' meaning that their annual production volumes ranged from
one million to more than one billion pounds. These chemical substances
were being used in a wide variety of applications, which resulted in
potential exposures of 1,000 or more workers to each chemical
substance. Based upon EPA's review of more recent production volume
data, exposure data, and dermal absorption rate data, which became
available after the proposal to this rule was published, EPA is now
requiring testing for 34 of the 47 chemicals that had been included in
the proposed rule. The rationale for EPA's decision not to finalize
testing requirements for the other 13 chemicals, which were originally
proposed for testing, is described in Unit VII.A. through I.
EPA is requiring that the 34 chemicals be tested according to the
in vitro dermal absorption rate test standard set forth in Sec.
799.5115(h) of the regulatory text. EPA has also specified reporting
requirements in Sec. 799.5115(i) of the regulatory text. EPA may
pursue testing of the remaining 32 chemicals based on further analysis.
In the solicitations discussed in this unit (Refs. 1, 2, 4, and
10), EPA referenced an in vitro dermal absorption rate test method for
review by potential submitters in developing their proposed protocols
(Ref. 10, p. 14776). This method was based on the peer reviewed method
of Bronaugh and Collier (Ref. 13). Some refinements of the method were
made by a panel of Federal scientists from ITC member and liaison
agencies (including, for example, Consumer Product Safety Commission
(CPSC), Department of Defense (DoD), EPA, Food and Drug Administration
(FDA), National Institute for Occupational Safety and Health (NIOSH),
and OSHA). EPA received public comments on the method and entered them,
along with the method itself, into the dockets for the 31\st\, 32\nd\,
and 35\th\ ITC Reports (docket control numbers OPPTS-41038, OPPTS-
41039, and OPPTS-41042, respectively). In addition, the American
Chemistry Council (ACC, formerly the Chemical Manufacturers Association
(CMA)) submitted a proposed protocol outlining
[[Page 22404]]
an alternative method (Refs. 14 and 14a.). Scientists from the Federal
Agencies represented on the ITC (including EPA and OSHA) reviewed the
public comments and the ACC proposal. As a result of this review, the
ITC and EPA scientists further refined the in vitro dermal absorption
rate test method of Bronaugh and Collier which EPA then proposed to be
the test standard required by this final rule (Ref. 5).
The test standard that will be required under this final rule
describes the procedures for measuring a permeability constant (Kp) and
two short-term absorption rates (10 minutes and 60 minutes) for
chemical substances in liquid form. A Kp is useful in estimating skin
permeation when contact with the chemical is prolonged (hours) and
steady state is achieved, while a short-term absorption rate
measurement is more relevant when the contact is short-term (minutes).
Both measurements are required by the test standard.
This test standard makes use of established in vitro diffusion cell
techniques that allow absorption rate studies to be conducted using
human cadaver skin and either flow-through or static diffusion cells
(see Sec. 799.5115(h) in the regulatory text). This test standard also
requires the use of radiolabeled chemical substances unless the test
sponsor can demonstrate that procedures utilizing a non-radiolabeled
test substance are able to measure the substance with equivalent
sensitivity. The first six parameters that are discussed under test
procedures in Sec. 799.5115(h)(5) of the regulatory text (i.e., choice
of membrane, preparation of membrane, diffusion cell design,
temperature, testing of hydrophobic chemicals, and vehicle) are similar
for the determination of either of the two percutaneous absorption rate
values (Kp and short-term absorption rate). In contrast, the remaining
two parameters (i.e., dose and study duration) are different for the
two percutaneous absorption rate values.
The in vitro approach was chosen not only for the practical
considerations that it makes efficient use of labor and materials and
can easily be performed by a variety of laboratories, but also because
in vitro diffusion cell studies are necessary for measuring a Kp.
Although the in vitro method in Sec. 799.5115(h) of the regulatory
text will satisfy OSHA's data needs to support its skin designations,
EPA does not believe the method is an adequate substitute for all
dermal absorption rate testing methods.
B. What is the Agency's Authority for Taking this Action?
This final rule is being promulgated under TSCA section 4 (15
U.S.C. 2603), which authorizes EPA to require the development of data
relevant to assessing the risk to health and the environment posed by
exposure to chemical substances and mixtures (chemicals).
Section 2(b)(1) of TSCA (15 U.S.C. 2603(b)(1)) states that it is
the policy of the United States that:
adequate data should be developed with respect to the effect of
chemical substances and mixtures on health and the environment and
that the development of such data should be the responsibility of
those who manufacture and those who process such chemical substances
and mixtures[.]
To implement this policy, TSCA section 4(a) mandates that EPA require
by rule that manufacturers and/or processors of chemical substances and
mixtures conduct testing if the Administrator finds that:
(1)(A)(i) the manufacture, distribution in commerce, processing,
use, or disposal of a chemical substance or mixture, or that any
combination of such activities, may present an unreasonable risk of
injury to health or the environment,
(ii) there are insufficient data and experience upon which the
effects of such manufacture, distribution in commerce, processing,
use, or disposal of such substance or mixture or any combination of
such activities on health or the environment can reasonably be
determined or predicted, and
(iii) testing of such substance or mixture with respect to such
effects is necessary to develop such data; or
(B)(i) a chemical substance or mixture is or will be produced in
substantial quantities, and (I) it enters or may reasonably be
anticipated to enter the environment in substantial quantities or
(II) there is or may be significant or substantial human exposure to
such substance or mixture,
(ii) there are insufficient data and experience upon which the
effects of the manufacture, distribution in commerce, processing,
use, or disposal of such substance or mixture or any combination of
such activities on health or the environment can reasonably be
determined or predicted, and
(iii) testing of such substance or mixture with respect to such
effects is necessary to develop such data [.]
The purpose of this testing is to develop data about the
substance's or mixture's health or environmental effects for which
there is an insufficiency of data and experience, and which are
relevant to a determination that the manufacture, distribution in
commerce, processing, use, or disposal of the substance or mixture, or
any combination of such activities, does or does not present an
unreasonable risk of injury to health or the environment.
Once the Administrator has made a finding under TSCA section
4(a)(1)(A)(i) (i.e., a finding that a chemical substance may present an
unreasonable risk of injury to health or the environment) or a finding
under TSCA section 4(a)(1)(B)(i) (i.e., a finding that a chemical
substance is or will be produced in substantial quantities and either
it enters or may reasonably be anticipated to enter the environment in
substantial quantities or there is or may be significant or substantial
human exposure to the chemical substance), EPA may require any type of
health or environmental effect testing necessary to address unanswered
questions about the effects of the chemical substance. EPA need not
limit the scope of testing required to the factual basis for the TSCA
section 4(a)(1)(A)(i) or (B)(i) findings, as long as EPA also finds
that there are insufficient data and experience upon which to
reasonably predict the effects of the manufacture, distribution in
commerce, processing, use, or disposal of such substance or mixture or
any combination of such activities on health or the environment, and
that testing is necessary to develop such data. This approach is
explained in more detail in EPA's statement of policy for making
findings under TSCA section 4(a)(1)(B) (frequently described as the
``B'' policy) (Ref. 55, pp. 28738-28739).
In this final rule, EPA is using its broad TSCA section 4(a)
authority to obtain dermal absorption rate data necessary for OSHA to
evaluate the need for ``skin designations'' (see Unit III.B.3.) for the
34 chemical substances specified in Table 2 in Sec. 799.5115(j) of the
regulatory text. Following consideration of the public comments
received by EPA on the proposed test rule (Ref. 5), EPA is making the
following findings for these chemicals under TSCA section 4(a)(1)(B):
They are produced in substantial quantities; there is or may be
substantial human exposure to them; existing data are insufficient to
determine or predict their health effects; and testing is necessary to
develop such data.
EPA has used its TSCA section 4(a) authority in the past to support
regulatory programs of other EPA offices as well as other Federal
Agencies needing health and/or environmental effects test data. See,
e.g., the final test rule for the Office of Water Chemicals (Ref. 68,
p. 59673).
[[Page 22405]]
III. Response to Public Comments
A. Summary
EPA received comments on the proposed rule (Ref. 5) from ACC,
Monsanto Company, First Chemical Corporation, American Forest and Paper
Association (AFPA), American Petroleum Institute (API), Biphenyl Work
Group, Diethyl Ether Producers Association (DEPA), Synthetic Organic
Chemical Manufacturers Association (SOCMA), Acetonitrile Task Force,
Dupont Dow Elastomers, Fragranced Products Information Network,
Association of Veterinarians for Animal Rights, People for the Ethical
Treatment of Animals, Animal Protection Institute Midwest Regional
Office, Humane Society of the United States, Doris Day Animal League,
Chlorobenzene Producers Association, Tetrahydrofuran Task Force
(THFTF), a private citizen, and Union Carbide Corporation (Refs. 15-
33).
ACC's Naphthalene Panel, Propylene Glycol Ethers Panel, Olefins
Panel (ACC/O), Hydrocarbon Solvents Panel, Ketones Panel and Oxo
Process Panel (ACC/KO), and Carbon Disulfide Panel, generally supported
the comments by ACC (Refs. 34-39). The Chlorobenzene Producers
Association, Biphenyl Work Group, and the Acetonitrile Task Force, also
endorsed the comments submitted by ACC. Comments by ACC and those
comments generally supportive of ACC's comments are collectively
referred to as ``ACC's'' hereinafter in this document. Comments
submitted by these groups that are specific to a chemical are
addressed, as appropriate, in Unit III.F. and in Unit VII.
A summary of the comments received by EPA on the Proposed Test Rule
for In Vitro Dermal Absorption Rate Testing of Certain Chemicals of
Interest to Occupational Safety and Health Administration is included
in this unit, along with EPA's responses to those comments. The
comments are available in the public docket for this rulemaking (see
ADDRESSES).
B. TSCA Section 4 Findings
1. ``Substantial'' human exposure, TSCA section 4(a)(1)(B)(i)(II)--
a. ``B'' policy. ACC commented that EPA has not provided a sufficient
basis for its finding of ``substantial'' human exposure under TSCA
section 4(a)(1)(B)(i)(II), (15 U.S.C. 2603(a)(1)(B)(i)(II)), with its
approach in this final rule which is based solely on numbers of people
exposed (more specifically, the number of workers exposed) to each
chemical. ACC asserts that a substantial human exposure finding must
additionally be based on information such as each chemical's physical,
chemical, and biological properties; the manner of use and release;
exposure concentrations; and duration and frequency of exposure. ACC
states that neither OSHA's objective of developing skin designations,
nor EPA's objectives under TSCA, are served by requiring dermal testing
in circumstances where dermal exposures are at low concentrations, or
are so infrequent that harm is not likely to occur.
EPA disagrees with ACC's assertion that EPA has not provided a
sufficient rationale for its finding that there is or may be
``substantial'' human exposure to the chemical substances that are
subject to this final rule as required under TSCA section
4(a)(1)(B)(i)(II). EPA also disagrees with ACC's contention that EPA
must consider chemical-specific factors to make a ``substantial'' human
exposure finding. In its policy statement that explains how EPA
generally makes findings under TSCA section 4(a)(1)(B)(i) (the ``B''
policy), EPA articulated quantitative thresholds to serve as guidance
in making findings of ``substantial'' production, release, and human
exposure. (Ref. 55) These quantitative thresholds are based on the
Agency's belief that it is reasonable to interpret the word
``substantial'' to mean exposure to large numbers of people. Therefore,
EPA believes that, in the case of this final rule, where, based on
information available to EPA (Refs. 5 and 56), 1,000 or more workers
are potentially exposed to each chemical for which the final rule would
require testing, it is reasonable to require the testing of each
chemical. In other words, EPA's policy (as articulated in its final
``B'' policy statement (Ref. 55)) is that quantitative data alone can
justify EPA's finding that production, potential release, or the number
of people potentially exposed to a chemical are ``substantial.'' This
is consistent with TSCA's goals of ensuring that, given the exposure of
humans and the environment to a large number of chemical substances and
mixtures with potentially harmful effects, there is effective
regulation of commerce in such substances (15 U.S.C. 2601(a)), that
adequate data be developed with respect to the effect of chemical
substances and mixtures on health and the environment, and that the
development of such data should be the responsibility of those who
manufacture and those who process these substances (15 U.S.C. 2601(b)).
Affected entities had the opportunity to comment on the proposed rule
and submit current employee information, readily available to them, to
refute EPA's finding that a substantial number of employees is exposed.
In those instances when EPA agreed with information submitted by
commenters which demonstrated that fewer than 1,000 employees were
exposed to a chemical, that chemical was not included in this final
rule (see Unit VII.D., E., and G.)
A ``substantial'' human exposure finding under TSCA section
4(a)(1)(B)(i)(II) requires no hazard or risk analysis (Ref. 55, p.
28742). Given the statutory framework, the legislative history, and the
case law interpreting the TSCA section 4 testing provisions, EPA does
not believe that it is required to consider each of the types of
information described by ACC in order to make a TSCA section
4(a)(1)(B)(i)(II) ``substantial'' human exposure finding (Ref. 55, p.
28742).
Although EPA is not required to consider the factors mentioned by
ACC in making its ``substantial'' human exposure findings, information
of the sort described by ACC is nevertheless relevant to other
decisions leading to a determination as to whether to require testing
under TSCA section 4. As stated in the Agency's ``B'' policy:
[f]or each substance-specific rulemaking under section 4, EPA
must determine whether there are sufficient `data and experience'
upon which to `reasonably determine or predict' the health and
environmental effects of a chemical substance, and whether testing
of such substance is `necessary to develop such data.' In making
these determinations, the Agency has always, and will continue to
examine all available and relevant information concerning the
substance in question, including the physical and biological
properties of the substance, the manner of its use and release, the
level, frequency, and duration of exposure, and any available
relevant exposure and toxicity data. It is the responsibility of
interested parties to provide any information they believe may be
relevant to the Agency's determination to require testing of a
particular chemical substance under TSCA section 4.
(Ref. 55, p. 28743).
In those instances where interested parties provided such relevant
information on chemical substances prior to the publication of this
final test rule, EPA and OSHA carefully reviewed the information and,
based on that review, EPA in some cases decided not to require testing
for those chemical substances. (See Unit VII.A. through G.).
b. The National Occupational Exposure Survey (NOES). ACC commented
that EPA has continued to rely on the NOES database to support its
findings of ``substantial'' human exposure, a data base which ACC
[[Page 22406]]
believes to be unrepresentative, incomplete, and outdated. ACC states
that the NOES estimates are greatly overstated and should not be relied
upon by EPA in making its findings. ACC provided a critique of the NOES
(Ref. 40) as support for its statements and added that EPA should
evaluate the level, frequency, and duration of exposure to each
chemical to determine if it is ``substantial.''
EPA disagrees with the commenter's statements regarding the
adequacy of the NOES for supporting a finding of ``substantial'' human
exposure under TSCA section 4(a)(1)(B)(i)(II). This database contains,
among other things, useful information on the approximate number of
workers potentially exposed to a chemical substance specified in the
database. That is to say, while the survey does not provide meaningful
information on the level, frequency, or duration of exposure, it is
useful for providing an estimate of the potential number of workers
exposed to a chemical. As noted in Unit III.B.1.a., EPA also does not
agree with the comment that EPA should undertake an exhaustive analysis
of exposure (i.e., level, frequency, and duration) to a chemical
substance to find that there is or may be ``substantial'' human
exposure.
For each of the chemicals for which testing is required in this
final rule, estimates of the number of exposed workers were identified
in the NOES. The NOES was a nationwide data gathering project conducted
by NIOSH, which was designed to develop national estimates for the
number of workers potentially exposed to various chemical, physical,
and biological agents and describe the distribution of those potential
exposures. Initiated in 1980 and completed in 1983, the survey involved
a walkthrough investigation by trained surveyors of 4,490 facilities in
523 different types of industries. Surveyors recorded potential
exposures when a chemical agent was likely to enter or contact a
worker's body for a minimum duration. These potential exposures could
be observed or inferred. Information from these representative
facilities was extrapolated to generate national estimates of
potentially exposed workers for more than 10,000 different chemicals
(Ref. 41). The NOES survey is the most recent and comprehensive source
of this kind of information.
In the critique of the NOES cited by ACC, a general conclusion of
the authors was:
We conclude from reviewing the survey design that, despite some
flaws, it represents one of the soundest approaches possible, within
the limited budget, for attaining national estimates of the number
of workers in the proximity of potentially hazardous agents.
(Ref. 40).
EPA agrees with this conclusion and believes that it is reasonable to
use information provided in the NOES database to support a finding of
``substantial'' human exposure for a chemical substance contained
within that database.
In addition, EPA agrees with the authors of the critique, Buell et
al (Ref. 40), that the survey results, while potentially useful for
making broad, national estimates of the number of persons in workplaces
where potentially hazardous agents are also present, should not be used
to gauge actual worker exposure to these agents, particularly to
individual chemicals in individual industry sectors. This information
was not collected in the survey. EPA has relied only on the information
in the NOES database regarding the approximate number of potentially
exposed workers in support of its finding of ``substantial'' human
exposure.
Because some time has passed since the NOES was completed, EPA
acknowledges that there may be instances where changes in various
industrial sectors (i.e., market demand, advances in technology, and
other mitigating factors) have led to a decrease in the number of
workers potentially exposed to certain chemical substances. EPA's
proposed test rule asked interested parties to provide any information
they believed relevant to the Agency's determination to require testing
of a particular chemical substance under TSCA section 4. EPA has
received additional exposure information on certain chemical substances
for which testing was proposed. This information has been fully
considered, and for those chemical substances for which EPA believes it
cannot make the ``substantial'' human exposure finding in light of such
information, the Agency is not finalizing testing requirements. (See
Units VII.D., E., and G.).
c. The Toxic Release Inventory (TRI). ACC stated that it is unclear
what role the TRI data played in making the TSCA section 4 findings in
the proposed rule, and that EPA should clarify how environmental
releases factor into a determination of occupational dermal exposures.
ACC notes that TSCA section 4(a)(1)(B), makes no mention of
``release,'' but refers to whether a substance ``enters'' the
environment. ACC asserts that in the context of TSCA section 4, the
word ``enter'' connotes presence in the environment. Accordingly, ACC
argues that ``release'' of a chemical in excess of one million pounds
per year is not necessarily evidence that the compound ``enters'' the
environment in ``substantial'' quantities. For example, if a substance
is dispersed, degraded, or reacted rapidly upon release from
manufacturing and processing facilities and is never present in
significant concentrations in air, water, or soil, ACC asserts that it
has not ``entered'' the environment in ``substantial'' quantities.
Moreover, ACC contends that environmental release, such as that
reported under section 313 of the Emergency Planning and Community
Right-to-Know Act (EPCRA), does not correlate well with dermal exposure
in the workplace. ACC notes that TRI reports do not indicate the
concentrations of listed substances in environmental media or the
extent of their distribution in the environment. Accordingly, ACC
asserts that the release quantities reported under section 313 of EPCRA
are not an adequate basis to support a TSCA section 4(a)(1)(B)(i)(I)
finding in the context of this final rule, and they should not be
combined with other data on the number of workers potentially exposed
to support such a finding.
Although EPA reviewed information contained in the TRI database to
identify additional support material for the test rule (Ref. 56), EPA
did not find it necessary to use TRI release data in developing its
exposure findings for this final rule.
d. TSCA sections 8(a) and 8(d). API commented that EPA does not
present results of data gathering in the 1993, 1994, and 1995 TSCA
section 8(a) and 8(d) rules (Refs. 6-8) for the proposed test rule
chemicals. API objects to EPA's issuing data gathering rules and then
not using the data gathered for the purposes of the test rule,
particularly given that it is 10 years more current than the data that
EPA used to make its TSCA section 4(a)(1)(B)(i)(II) finding i.e., NOES
data (Ref. 19).
Following the EPA Administrator's receipt of the ITC Reports (Refs.
1, 2, and 4) which designated 83 chemicals for priority testing, the
EPA's Office of Pollution Prevention and Toxics (OPPT) promulgated TSCA
section 8(a) Preliminary Assessment Information Reporting (PAIR) and
TSCA section 8(d) Health and Safety Data rules (Refs. 6-8) for the 83
chemicals designated for testing by the ITC. The TSCA section 8(a) rule
required manufacturers and importers of chemicals designated for
testing by the ITC to submit production
[[Page 22407]]
and exposure reports. The TSCA section 8(d) rule required manufacturers
(including importers), and processors of chemicals designated for
testing by the ITC to submit unpublished health and safety studies.
These rules are automatically promulgated by EPA unless the ITC
requests that EPA not do so.
The ITC reviews the TSCA section 8(a) PAIR reports, TSCA section
8(d) studies, and ``other information'' that become available after the
ITC adds chemicals to the Priority Testing List. ``Other information''
includes TSCA section 4(a) studies, TSCA section 8(c) submissions, TSCA
8(e) ``substantial risk'' notices, ``For Your Information'' (FYI)
submissions, ITC-FYI voluntary submissions, unpublished data submitted
to U.S. Government organizations represented on the ITC, published
papers, as well as use, exposure, effects, and persistence data that
are voluntarily submitted to the ITC by manufacturers, importers,
processors, and users of chemicals recommended by the ITC. The
submissions are indexed and maintained by EPA. After the ITC reviews
this information it determines if data needs should be revised, if
chemicals should be removed from the Priority Testing List, or if
recommendations should be changed to designations.
EPA disagrees with the comment that data gathered under TSCA
section 8(a) and 8(d) rules were not considered in preparing the
proposal. In fact, the proposed rule described the ITC's use of the
data from the TSCA section 8(d) rules to support withdrawing its
designation for three chemicals. As described in the proposal (Ref. 5,
p. 31077), the ITC received dermal absorption rate data for three
chemicals after EPA had promulgated TSCA section 8(d) rules for these
chemicals. The ITC determined that the dermal absorption rate data for
these three chemicals would meet OSHA's data needs, and accordingly,
the ITC withdrew its designation for these three chemicals: Methyl
methacrylate and diethyl phthalate in the 34\th\ ITC Report (Ref. 3, p.
35725), and cyclohexanone in the 36\th\ ITC Report (Ref. 9, p. 42987).
Furthermore, the ITC's review of the data gathered under TSCA
sections 8(a) and 8(d) for the 80 remaining designated chemicals did
not provide a sufficient rationale for the ITC to make a determination
that the specified data needs should be revised or that its designation
of chemicals for in vitro dermal absorption rate testing should be
withdrawn and those chemicals removed from its Priority Testing List.
The proposed rule also described EPA's use of production data as a
basis for its decision to pursue rulemaking on only 47 of the remaining
80 designated chemicals because of their greater production volumes,
data which were reported under the TSCA section 8(a) rules (Ref. 5, p.
31077). Although EPA considered the information on employee exposure at
manufacturing sites provided in the TSCA section 8(a) submissions, EPA
also relied on NOES data as they indicate what additional employee
exposure may occur at processing facilities.
Finally, for those remaining 32 chemicals designated for in vitro
dermal absorption rate testing by the ITC which are not addressed by
this final rule, EPA will present any determinations regarding data
gathered from TSCA section 8(a) and 8(d), as well as any other
available data in any future proposal for those chemicals.
2. ``Data are insufficient,'' TSCA 4(a)(1)(B)(ii). DEPA (Ref. 21),
the Chlorobenzene Producers Association (Ref. 31), and the Union
Carbide Corporation (Ref. 47) challenged the Agency's finding that data
are insufficient to determine a dermal absorption rate for ethyl ether,
o-dichlorobenzene, and n-amyl acetate, respectively. These commenters
provided studies to support their claims that available data are
sufficient to determine dermal absorption rates. ACC (Ref. 15)
commented that isobutyl alcohol and sec-butyl alcohol are structurally
similar to other alcohols for which data have been generated and that a
structure-activity relationship (SAR) approach could be used to predict
the dermal absorption rates of these two chemicals. EPA reviewed the
submitted studies and agreed that the available data are sufficient at
this time to adequately determine or predict dermal absorption rates
for these five chemicals. See Unit VII.A. through C. and F. for a
description of the submitted studies and the basis for EPA's decision
not to pursue rulemaking on these five chemicals.
3. ``Testing is necessary,'' TSCA section 4(a)(1)(B)(iii). ACC
commented that EPA failed to demonstrate that the proposed testing is
necessary to develop data to predict the effects of the chemicals on
human health and the environment (Ref. 15). ACC also stated that the
Agency has provided no information on the need for dermal absorption
data to ``support chemical risk assessments at EPA as well as at other
Federal agencies.'' As a general matter, ACC believes that EPA should
not require testing when the Agency has not determined how the data
will be used, and indeed cannot conclude that testing is necessary in
such a case. Similarly, API and THFTF (Refs. 19 and 32) requested that
EPA explain how the Agency (or other Federal Agencies) might use the
dermal test data.
EPA believes it has adequately demonstrated a need for the testing
that will be conducted under this final rule. As discussed in the
preamble to the proposed rule (Ref. 5, pp. 31076-31078) and in the
31\st\, 32\nd\, and 35\th\ ITC Reports to the Administrator (Refs. 1,
2, and 4, respectively), OSHA has found that for many toxic substances
to which workers are exposed via multiple routes, and specifically for
the chemical substances for which testing will be required under this
final rule, very little knowledge exists of the contribution of dermal
exposure to the total body burden of the substance.
Dermal absorption rate data for toxic substances encountered in
industrial and occupational settings are quantitative estimates of the
rate (amount per specified period of time) at which substances pass
through the layers of the skin to enter the systemic circulation. OSHA
assigns a ``skin designation'' to a chemical if it determines that
cutaneous exposure (through the skin, eyes, and mucous membranes) to
the chemical may result in systemic toxicity. In order to assign a skin
designation for a chemical substance, OSHA requires dermal absorption
rate data. OSHA requested (Refs. 1, 2, and 4) that the ITC help
identify chemicals which lack sufficient data for OSHA to develop skin
designations and to use its authority to recommend chemicals for
priority testing consideration by EPA to obtain these data.
As described in the proposed rule, the ITC performed searches for
data relating to the chemicals on the following databases: RTECS
(Registry of Toxic Effects of Chemical Substances), TOXLINE (TOXicology
of information onLINE), MEDLINE (MEDlars onLINE), TOXLIT (TOXicology
LITerature from special sources), CECATS (OPPT/Risk Assessment
Division/Chemical Screening Branch's Existing Chemical Assessment
Tracking System), TSCATS (Toxic Substances Control Act Test
Submissions), and INDEX MEDICUS. The search strategy was designed to
identify any toxicological tests that used the dermal route of
exposure. The information from the searches was collected and the
chemicals were subcategorized based on the number of postings (Ref. 2,
p. 38493).
Also as described in the proposed rule, in addition to these
literature searches, the ITC reviewed data from
[[Page 22408]]
TSCA section 8(a) and 8(d) rules (Refs. 6 through 8) which were
promulgated by EPA for the chemical substances included in the 31\st\,
32\nd\, and 35\th\ ITC Reports (Refs. 1, 2, and 4). These rules
required the reporting to EPA of certain production, use and exposure-
related information, and unpublished health and safety data concerning
these chemicals. For the 34 chemicals for which in vitro dermal
absorption rate testing is required under this final rule, there was
either no dermal absorption rate information available or available
data were insufficient to derive a dermal absorption rate.
Testing of the 34 subject chemical substances is necessary to
develop dermal absorption rate data. Dermal absorption rate data
derived from testing these 34 chemical substances are needed by OSHA to
estimate the amount of the chemical substance absorbed after contact
with the skin. Only when dermal absorption is considered along with
inhalation exposure data can a more complete and accurate quantitative
assessment of body burden be estimated. Accurate estimates of body
burden are necessary to develop assessments of risk to worker health
posed by exposures to toxic substances in the workplace. This testing
is needed to determine if the manufacturing, processing, or use of
these 34 chemical substances presents an unreasonable risk of injury to
human health.
In addition to playing an important role in assessing body burden,
dermal absorption rate data can generate useful quantitative
information for making recommendations or decisions concerning
engineering controls or employee use of personal protective clothing to
prevent exposure by the dermal route. Such information, when considered
in conjunction with toxicologic and health effects data, can be used by
industrial hygienists, other occupational health professionals,
employers, and workers. Dermal absorption information is useful for
hazard communication and right-to-know purposes, including Material
Safety Data Sheets, and product labels. Additionally, dermal absorption
rate data for chemicals used or produced in particular work sites are
useful in developing comprehensive safety and health programs at those
facilities.
OSHA standards, including skin designations, are widely applied and
referenced. Local, State, and county governments, and other Federal
Agencies rely on OSHA's occupational standards, as do other national
governments. It is both appropriate and necessary to require dermal
absorption rate testing of these industrial chemicals.
Although OSHA is the primary agency requesting the data that will
be developed under this final rule, OSHA is not the only Federal Agency
that will use the data. NIOSH is also very interested in method-related
issues associated with characterizing dermal exposure and advancing
improvements in occupational exposure assessments.
EPA is also interested in data that may be gathered on these
chemicals. The information obtained by the testing required in this
final rule may be used to inform the Agency's decisionmaking process by
providing data which can be used in a preliminary estimate of the
potential health risk of certain chemical exposures. The 34 chemicals
for which testing is required under this final rule are part of other
ongoing Agency efforts. For example, all 34 chemicals are included in
EPA's High Production Volume (HPV) Initiative (http://www.epa.gov/chemrtk.htm.) In addition, EPA's Voluntary Children's Chemical
Evaluation Program (VCCEP) (Ref. 43) is designed to provide data to
enable the public to better understand the potential health risks to
children associated with certain chemical exposures. Four of the 34
chemicals are included in EPA's VCCEP: Vinylidene chloride (Chemical
Abstract Service Registry Number (CAS No.) 75-35-4); p-dichlorobenzene
(CAS No. 106-46-7); ethylene dichloride (CAS No. 107-06-2); and
chlorobenzene (CAS No. 108-90-7). (See http://www.epa.gov/chemrtk/childhlt.htm.). While in vitro dermal absorption rate data are not
being developed under either of these Agency efforts, the data may be
of benefit in preliminary risk screening, which is the purpose of data
gathering in the HPV Initiative. Dermal absorption rate data may also
be beneficial in further consideration of chemicals to which children
may be exposed. Thus, EPA may use data obtained under this test rule in
preliminary risk screenings to support its HPV Initiative and VCCEP, or
for other Agency efforts to protect human health and the environment
from unreasonable risks resulting from the manufacture, processing, or
use of chemicals.
In summary, the data developed under this test rule will assist the
Agency and others in evaluating these chemical substances for potential
health or safety risk concerns. Although it is not an independent basis
for supporting this final rule, as an additional benefit, the data will
be publicly available, and thus will serve to further the Agency's goal
of identifying and controlling human health and environmental risks by
providing greater knowledge to the public.
C. Categories
ACC (Ref. 15) believes that EPA should consider a category approach
to dermal absorption rate testing. In reviewing the list of 79 ITC-
designated chemicals, ACC concludes that a great majority can be
grouped into categories of similar chemical structure and that selected
chemicals from each category could be tested for the purpose of
obtaining sufficient data that would allow an accurate prediction of
dermal absorption rate for other members of the structural group
through a combination of modeling and quantitative structure activity
relationship (QSAR) analysis. ACC states that for the designated
chemicals, these categories would include aliphatic alcohols, ketones,
aliphatic hydrocarbons, nitroaliphatics, halogenated hydrocarbons,
aliphatic esters, aromatic hydrocarbons, nitroaromatics, halogenated
aromatics, amides, aromatic amines, and phenols/phenol ethers. ACC
suggests that the data generated from testing chemicals within
categories could then be combined with existing data on other category
members (including those in the larger group of 658 workplace chemicals
that were originally nominated for testing by OSHA) to attempt to
correlate chemical structure with dermal absorption rates.
EPA disagrees with the category approach suggested by ACC as an
alternative to the approach proposed by EPA for testing these
chemicals. ACC has not provided specifics on the number of chemicals in
each category that would need to be tested and the reason certain
chemicals would be representative so that reliable structure activity
predictions could be made. Twelve different structural classes were
mentioned as potential categories by ACC, but additional classes would
likely be needed to categorize within the group of 79 chemicals that
have been designated for testing by the ITC. EPA remains unconvinced
that the approach suggested by ACC will either minimize the testing
burden or more efficiently develop data on the chemicals of interest.
However, the results from the dermal absorption rate testing of the
chemicals in this final rule could, in appropriate cases, provide
additional data for more thorough QSAR analysis and better validated
models for future predictions.
D. Use of Calculated Kps to Screen and Prioritize Chemicals
ACC commented that adequate data already exist to ``reasonably
determine
[[Page 22409]]
or predict adverse effects,'' according to TSCA 4(a)(1)(B), for most if
not all of the chemicals included in the proposed test rule (Ref. 15).
It is ACC's understanding that the ITC calculated dermal penetration
rates (Kps) for all of the chemicals covered by the test rule. ACC also
notes that in 1992, EPA published guidance for estimating Kps for
organic chemicals (see Ref. 42). The guidance document included
calculated Kps for 11 of the 47 chemicals proposed for testing. In
addition, ACC indicates that EPA's 1992 methodology has been largely
validated, as the calculated Kps closely approximate available
experimentally determined penetration rates. As such, ACC asserts that
Kps, estimated using the suggested methodology, would be of sufficient
quality to be used in screening-level assessments to determine the
likely influence of dermal exposure on total worker exposure (i.e., the
need for OSHA skin designations).
ACC states that EPA should consider giving industry the option of
using calculated Kp values in lieu of testing, and together with
industry and OSHA, assess the feasibility of using such data before the
final rule is promulgated. ACC also states that, at a minimum, EPA
should consider using calculated Kp data in order to screen and
prioritize the chemicals for the proposed dermal absorption rate
testing (Ref. 15). To do this, ACC states that prior to requiring
testing the available calculated Kp data should be used to screen
chemicals for their potential to cause systemic toxicity as a result of
dermal exposure by assessing the potential contribution of dermal
exposures to total occupational exposures, and that this assessment
should be used to prioritize testing needs. ACC believes that the
dermal absorption rate testing should be reserved for those chemicals
for which screening-level assessments indicate the dermal pathway may
be of concern. ACC comments that neither OSHA nor EPA has attempted to
prioritize chemicals using published EPA dermal exposure assessment
guidance, including published estimated dermal penetration rates.
EPA disagrees that adequate data exist to ``reasonably determine or
predict adverse effects,'' according to TSCA 4(a)(1)(B), for the
chemicals included in the final test rule. As an initial matter, EPA
believes that measured Kps (i.e., those determined through well
designed and conducted in vitro or in vivo testing experiments) are
generally more reliable than calculated Kps, and measured Kps are not
available for the 34 chemicals subject to this final rule. EPA further
believes that calculated Kp data may not be sufficiently reliable to be
used in lieu of testing or in screening-level assessments to prioritize
testing needs when the most relevant worker exposures involve exposure
to neat compounds or compounds dissolved in organic solvents. With
respect to the chemicals for which measured Kps are presented in Table
5-8 in EPA's 1992 guidance document (Ref. 42), the Kps were measured
exclusively for the chemicals when they were in aqueous solutions; the
table presents no measured Kps for neat liquids or chemicals in organic
solvents, both of which are generally expected to be more relevant to
the workplace (Ref. 62). Thus, these data are not adequate to provide
the information needed for OSHA's intended purpose (Ref. 62). However,
the in vitro testing required by this final rule, in addition to
developing data needed to assess the potential risk of the 34 subject
chemicals, will expand the existing data base and allow more thorough
comparisons of measured Kps with calculated Kps relevant to
occupational exposures.
E. Comments on Proposed In Vitro Test Standard
1. General. EPA received comments supporting use of the proposed
test standard from several groups and individuals (Refs. 25-30). Many
of these comments were similar in that they supported the standard as a
means of gathering data without utilizing laboratory animals.
EPA agrees that there are instances, such as utilizing the test
standard articulated in this final rule, in which sufficient data on
the dermal absorption rate of a chemical substance may be gathered
without using live laboratory animals. EPA considers many factors in
relying upon specific test methods in its proposals under TSCA section
4. In specifying the standard for this rulemaking, the ITC and EPA
considered the views of the public commenters, Federal scientists, and
laboratories capable of conducting such testing. The standard
articulated in this rulemaking makes efficient use of labor and
materials and can be performed in a consistent, economical, and timely
manner by different laboratories. The specification of the in vitro
method as the test standard for this final rule also reflects EPA
efforts to reduce the use of animals, where appropriate, in its testing
programs. However, as noted previously in Unit II.A., although this in
vitro method will satisfy OSHA's data needs to support its skin
designations, EPA does not believe the method is an adequate substitute
for all dermal absorption rate testing methods.
2. Technical. In addition to the general comments received by EPA
on the proposed test standard, EPA also received technical comments
from ACC, API, THFTF, DEPA, and a private citizen. In general,
commenters argue that the proposed test standard was unnecessarily
rigid and that several improvements would provide greater flexibility
and reduce the cost of testing. EPA and OSHA agree with a number of the
changes recommended by ACC , API, and THFTF, and have revised the test
standard accordingly, as described in this unit.
a. ACC, API, and THFTF commented that both static and flow-through
in vitro cells have been found acceptable in estimating dermal
penetration of compounds. EPA agrees. Both static and flow-through in
vitro cells, as described by the commenters and in the international
Organization for Economic Co-operation and Development (OECD) draft
guidance document (Ref. 44), are acceptable for estimating dermal
penetration of compounds (Ref. 62). EPA has modified the test standard
at paragraph (h)(5)(iii) to read: ``Either static or flow-through
diffusion cells must be used in these studies.''
b. EPA received a comment from a private citizen (Ref. 33) who
believes that more scientifically valid dermal absorption rates would
be obtained by using the technologically more advanced flow-through
type cells and viable human skin instead of the older method using
static diffusion cells and cadaver skin.
EPA agrees that in some instances it may be preferable to utilize
flow-through cell types and viable human skin to generate dermal
absorption rate data. Based on this comment and similar comments by
ACC, API, and THFTF, EPA has modified the test standard to allow the
use of either flow-through cells or static diffusion cells in
developing the data required under this final rule (See Sec.
799.5115(h)(5)(iii) of the regulatory text). However, although EPA
agrees that utilizing viable human skin could provide more reliable
data, EPA is requiring that human cadaver skin be utilized for all
testing required in this action. EPA's rationale for this decision is
described in Unit III.E.2.o.ix.
c. ACC commented that heat treatment to separate epidermis from
dermis is an acceptable alternative to dermatome slicing for preparing
epidermal membranes. EPA agrees. The use of a dermatome prepared skin
membrane of a thickness of 200 to 500 micrometers (um) is but one
scientifically acceptable method of preparation. Peeling the epidermis
from the dermis after heat treatment at 60[deg] C
[[Page 22410]]
for 45 seconds, as recommended by ACC (Ref. 15), or 1 to 2 minutes, as
specified in the draft OECD guidance document (Ref. 44), is also a
scientifically accepted means of preparing the test membrane (Ref. 62).
In response to this comment, EPA specified a time range of 45 seconds
to 2 minutes as the time for heat treatment to include the two
recommended treatment times in the ACC and OECD methods (45 seconds and
1 to 2 minutes, respectively). EPA modified the required test standard
Sec. 799.5115(h)(5)(ii) to read:
A suitable membrane must be prepared from skin either with a
dermatome at a thickness of 200 to 500 micrometers (um), or with
heat separation by treating the skin at 60[deg] C for 45 seconds to
2 minutes after which the epidermis can be peeled from the dermis.
d. ACC and THFTF commented that the requirement that barrier
properties of human cadaver skin must be pretested with a standard
compound such as tritiated water prior to conducting the study should
be expanded to include suitable alternatives to the use of tritiated
water. (See Howes, et al., Methods for Assessing Absorption, in ECVAM
Workshop Report 13, J.H. Fentem, ed., European Center for the
Validation of Alternative Methods, 94-95 (Ispra, Italy 1996)). EPA
agrees. Membrane integrity checks conducted with transepidermal water
loss (TEWL) or electrical resistance, as described by the commenters
and in the OECD guidance document (Ref. 44), are acceptable
alternatives to dermal penetration of tritiated water for the
evaluation of human cadaver skin integrity (Ref. 62). EPA has modified
the test standard in Sec. 799.5115(h)(5)(i)(D) to read:
Prior to conducting an experiment with the test substance,
barrier properties of human cadaver skin must be pretested either
by:
(1) measuring the movement of a standard compound such as
tritiated water as discussed, for example, in the reference in Sec.
799.5115(h)(8)(i),
(2) determining an electrical resistance to an alternating
current, at up to two volts, or
(3) measuring trans-epidermal water loss from the stratum
corneum.
e. API, THFTF, and ACC commented that human cadaver skin samples
can be stored frozen for periods longer than 2 weeks, as proposed by
EPA. Frozen storage, even for longer periods of time, does not
adversely affect the integrity of the dermal barrier (see Ref. 45).
EPA agrees that for purposes of this test rule, the human cadaver
skin samples can be stored frozen for periods longer than 2 weeks.
However, EPA does not agree with ACC that skin samples can be frozen
for up to 18 months without changes in penetration rates for standard
compounds. EPA does not believe that a single report (Ref. 45) of
acceptable skin penetration using a single substance (water) with
membranes frozen for 466 days justifies extending the standard storage
period to 18 months. Most of the chemicals designated for testing in
this final rule are organic chemicals with chemical properties quite
different from water. EPA believes it is reasonable to extend the
maximum period of time during which human cadaver skin samples can be
stored frozen (-20[deg] C) to 3 months (Ref. 62). This period of time
is consistent with OECD guidance (Ref. 44). In response to these
comments, EPA has modified the test standard in Sec.
799.5115(h)(5)(ii) to read:
These epidermal membranes can be stored frozen (-20[deg] C) for up
to 3 months, if necessary, if they are frozen quickly and the barrier
properties of the samples are confirmed immediately prior to
commencement of the experiment.
f. THFTF commented that EPA should allow a longer, though
unspecified, amount of time for study completion. THFTF cited three
circumstances which would make more time necessary:
The practical ability of companies to test
multiple materials.
The availability of contract facilities to
conduct the testing.
The extra time needed to synthesize radiolabeled
material.
EPA agrees. Circumstances may arise where the proposed 9 months
would be an insufficient amount of time to complete testing. Therefore,
EPA is extending the period of time provided to complete the required
testing from 9 months to 13 months which EPA believes should
accommodate the circumstances cited by THFTF.
g. ACC and THFTF noted that the test standard requires a full
balance sheet to demonstrate recovery of radioactivity. (A ``full
balance'' refers to a determination of where the radiolabel is present
at the conclusion of the experiment (i.e., in the receptor fluid, skin
sample, test vehicle, or diffusion cell) and that the recovery of
radioactivity in the test system is nearly 100%). Commenters stated
that it is unclear whether this requirement applies to Kp studies, to
studies to measure short-term absorption rates, or both. They assert
that full balance sheets are not necessary for studies in which Kp is
being determined. Additionally, they commented that small losses of the
test article do not affect the outcome of the studies because the study
is, by definition, conducted with an infinite dose. (Infinite dose is
the amount of test preparation applied to the skin where a maximum
absorption rate is achieved and maintained because such a volume
ensures continuous excess of test preparation in the donor chamber.)
(Ref. 44). Commenters requested that EPA clarify how accounting for
losses affects Kp values.
EPA believes the test standard should require that a full balance
of radioactivity be presented for both Kp and short-term absorption
rate studies, as proposed. While EPA agrees that small losses of test
compound are tolerable in the infinite dose design, it is,
nevertheless, considered good laboratory procedure and does not require
excessive effort to assess recovery in experiments using radiolabeled
compound (Ref. 62).
h. ACC and API (Refs. 15 and 19) commented that the use of
isopropyl myristate (IPM) as a solvent in the proposed test standard is
inappropriate. ACC and API stated that IPM, although frequently used as
a vehicle in various dermatological formulations, has questionable
applicability in an occupational environment to the chemicals subject
to this test rule. ACC and API also stated that IPM may not mimic
workplace conditions and if used, some corrective factor should be
applied to determine the rate of percutaneous absorption.
EPA disagrees. IPM is an appropriate all-purpose solvent for the
rare instances in which certain water insoluble substances capable of
damaging skin are being tested (Ref. 62). ACC has not provided evidence
to suggest that use of IPM will generate distorted Kp values
unrepresentative of occupational settings. If such evidence exists, EPA
is willing to consider, via the procedures specified at 40 CFR 790.55,
in vitro percutaneous absorption experiments with other vehicles for
specific test chemicals, if the test sponsor demonstrates that their
vehicle is more representative of relevant occupational exposure than
IPM. EPA will not speculate on what, if any, adjustments might be made
to Kp values determined by the test standard in order ``to reflect
realistic exposure scenarios'' or to account for differences in
regional absorption for skin.
i. ACC noted that the preamble to the proposed rule indicates that
the parent chemical and its major metabolites are to be detected in
certain cases, and requested clarification as to which of the major
metabolites of the chemicals this requirement applies.
In the proposal to this action, EPA mentioned that the measurement
of major metabolites in the receptor fluid
[[Page 22411]]
is done when viable skin is used and significant dermal metabolism is
anticipated. However, EPA did not propose nor is EPA requiring that
live skin be used and skin viability be maintained during performance
of the required tests. Therefore, EPA is also not requiring measurement
of major metabolites in the receptor fluid. (See Unit III.E.2.o.ix.).
j. ACC was unsure whether EPA's proposed test standard would
require the use of 6 or 18 human cadaver skin samples per chemical. EPA
is requiring a minimum of 18 human cadaver skin samples per chemical.
EPA has modified the test standard at Sec. 799.5115(h)(5)(i)(B) to
clarify that data must be obtained from a minimum of six samples for
each of the determinations, i.e., Kp, 10-minute short-term absorption
rate, and 60-minute short-term absorption rate. Also, the samples used
for the testing of a given chemical must come from at least three
different human subjects, with two samples from each subject being used
for each determination to allow for biological variation among
subjects. (See Sec. 799.5115(h)(5)(i)(B) of the regulatory text).
k. ACC commented that in Sec. 799.5115(h)(5)(v) of the proposed
regulatory text it is unclear whether it is necessary to demonstrate
that the concentration of a test substance in the donor chamber has
remained at greater than 90% of its original value, or that the
concentration of the test substance in the receptor fluid is less than
10% of the initial test substance concentration in the donor chamber.
Similarly, THFTF commented that Sec. 799.5115(h)(5)(v) of the proposed
regulatory text should be revised to state that physicochemical data or
experimental results should be used to show that about 10 times the
concentration in the receptor fluid is achievable under experimental
conditions. This will ensure that back diffusion is not significant.
See the OECD Guideline 1999 (Ref. 44).
EPA has removed the language in question in Sec. 799.5115(h)(5)(v)
of the regulatory text, and has inserted related text in the test
standard at Sec. 799.5115(h)(5)(iii) to read:
To ensure that an increase in concentration of the test
substance in the receptor fluid does not alter penetration rate, the
testing laboratory must verify that the concentration of the test
substance in the receptor fluid is less than 10% of the initial
concentration in the donor chamber.
This requirement applies to all chemicals to be tested, including
hydrophobic chemicals.
l. ACC commented that there is some confusion created by
inconsistencies between statements in the proposed rule preamble and
requirements in the proposed test standard. ACC points out that the
preamble states that ``the measurement of a short-term absorption rate
is only required when a Kp cannot be obtained using this standard,''
whereas Sec. 799.5115(h)(5)(vii)(B) of the proposed regulatory text
states that ``Short-term absorption rates must be determined for all
chemicals.'' It is not clear to ACC why short-term absorption rates
must be determined for all test chemicals. ACC believes that if a
chemical affects the skin and a Kp value cannot be determined,
determining a Kp rate is moot. Knowledge of the short-term rate is not
useful in determining Kp values. API similarly commented that it is not
clear why determining the short-term absorption rate for each test rule
chemical is necessary.
EPA is requiring the measurement of short-term absorption rates for
all chemicals included in this final rule. The panel of Federal
scientists that refined the method of Bronaugh and Collier (Ref. 13)
recommended that all chemicals be tested for short-term absorption in
order to obtain in vitro dermal absorption rate measurements for brief
dermal exposures that commonly occur in occupational settings, such as
spills or splashes. EPA believes that the panel's rationale supporting
the testing of all chemicals for short-term absorption is reasonable.
m. ACC and THFTF commented that the correct unit of measurement is
micrometers, not millimeters, as stated in Sec. 799.5115(h)(5)(ii) of
the proposed regulatory text. EPA agrees that the correct unit of
measurement is micrometers, not millimeters. EPA has corrected the test
standard in Sec. 799.5115(h)(5)(ii) of the regulatory text to reflect
this.
n. DEPA argues that the proposed test standard is unacceptable for
measuring very volatile liquids, such as ethyl ether, because efforts
to prevent evaporation would lead to unrealistically high pressures,
leakage of material from the cell, damage to the skin membrane, and
other substantial technical difficulties. EPA disagrees. DEPA did not
provide any evidence to suggest, nor is EPA aware, that any such
problems have ever been reported. However, in those instances where a
test sponsor can document that closed (i.e., occluded) conditions lead
to leakage of material or damage to the skin membrane or similar
technical difficulties, in vitro percutaneous dermal absorption rate
experiments with the skin surfaces uncovered (unoccluded) may be
substituted, via the provisions in 40 CFR 790.55, if EPA agrees that
conducting the study in such a manner is more technically feasible and
appropriate.
o. THFTF suggested numerous minor changes to the test standard that
EPA believes go against either the recommendations of the ITC expert
panel or TSCA Good Laboratory Practice Standards (GLPS) at 40 CFR part
792, and do not enhance the validity or acceptability of the method.
The suggested changes include:
i. Removing the requirement that the time elapsed between the death
and harvest of human skin specimens be reported. EPA believes that all
experimental parameters should be reported in accordance with TSCA
GLPS, and has retained this requirement in the final rule.
ii. Removing the requirement that the thickness of the skin
membrane be reported. EPA believes that all experimental parameters
should be reported in accordance with TSCA GLPS, and has retained this
requirement in the final rule.
iii. Requiring solids to be applied directly to the skin and
determining percentage absorbed rather than dissolving solids in a
vehicle and determining Kp. EPA disagrees. Although there may be
instances where some of the test rule chemicals that are solids at room
temperature have dermal exposures limited to the chemical in solid
form, it is also possible based on common industrial practices, that
there will be occupational exposures to these chemicals when they are
dissolved or suspended in an aqueous or solvent medium. In addition,
test solutions are more suitable for determining Kp values for
chemicals that are solids at room temperature. This is because
solutions in contact with the skin are uniform and have known
concentrations, which is not necessarily the case with solids in
contact with skin (Ref. 63). Therefore, EPA is generally requiring, as
proposed, that chemicals that are solids at room temperature be
dissolved in water. If the chemical is hydrophobic and its
concentration in water is not high enough to obtain a steady-state
absorption, the chemical must be dissolved in isopropyl myristate.
However, in those instances where a test sponsor can document that
occupational exposure is limited to a chemical in solid form,
development of percutaneous dermal absorption rate experiments with
solid material may be substituted, via the provisions contained in 40
CFR 790.55, if EPA agrees that conducting the study in such a manner is
more appropriate.
iv. Specifying fixed amounts of test chemical, 10 milligrams per
centimeter
[[Page 22412]]
squared (mg/cm\2\) for dry solid or 10 microliters per centimeter
squared (ul/cm\2\) for liquids, be used in short-term absorption rate
experiments rather than simply requiring the use of sufficient test
chemical to cover the skin and reporting the quantity used. EPA
disagrees. It is not necessary to specify that all substances be tested
at the same fixed volume per skin area. The size of the diffusion
chamber will partially determine the volume of required test material.
The important issue is that sufficient test chemical is available to
completely cover the skin. This is because the absorption rate of a
chemical is reported per square centimeter of skin, thus, it is
necessary to precisely ascertain the area of skin contacted (Ref. 63).
v. Requiring three rather than four absorption measurements for
determination of Kp. EPA disagrees. The panel of Federal scientists
that refined the Bronaugh and Collier method (Ref. 13) for use as the
test standard in this final rule believes that three measurements
during the steady state absorption period are inadequate to accurately
determine the Kp and that an additional measurement is necessary for
this purpose (Ref. 62). As a result, EPA is retaining the requirement
in this final rule that four absorption measurements be taken for the
determination of a Kp.
vi. Specifying that exposure time should be up to 8 hours for
estimating dermal absorption of finite doses. EPA disagrees. EPA does
not believe that it will be necessary to test each of the chemicals for
as long as 8 hours. In fact in many instances, the study can be
completed in an hour. However, there may be chemicals for which the
study could require up to 24 hours to complete. Therefore, EPA believes
that specifying a study duration of up to 8 hours is inappropriate
(Ref. 63). However, if a test sponsor provides EPA with documentation
that an alternate exposure time for a specific chemical is more
relevant than the exposure time specified in this final rule, EPA may
provide for the substitution of other exposure durations for the
development of in vitro percutaneous dermal absorption rate
experiments, via the provisions contained in 40 CFR 790.55, if EPA
agrees that conducting the study in such a manner is more appropriate.
vii. Allowing 1:1 ethanol:water to be used as receptor fluid for
hydrophobic chemicals in addition to 6% polyethylene glycol (PEG) in
water. EPA agrees that a 1:1 ratio of ethanol to water is a suitable
receptor fluid for hydrophobic chemicals. However, EPA is specifying
that the PEG receptor solvent at a concentration of 6% be used for
testing of hydrophobic chemicals. EPA believes that specifying the use
of the single PEG receptor solvent for these chemicals should ensure
more uniform and consistent results. Specifying that a single receptor
fluid be used for all hydrophobic chemicals will enhance the
interpretability of test results for these chemicals (Ref. 63).
viii. Not expressing short-term finite absorption as a rate, i.e.,
micrograms per hour per centimeter squared (ug/h/cm\2\), because the
true absorption rate is likely to change over the time interval during
which absorption is being measured. This is to be distinguished from Kp
determinations at steady state conditions under which there is little
change in an absorption rate over time. The commenter suggests that
cumulative amount absorbed per area, i.e., micrograms per centimeter
squared (ug/cm\2\) is a more appropriate way to express the data.
EPA disagrees. EPA is aware of the distinctions between a short-
term absorption rate measured under non-steady state conditions and a
Kp value based on a steady state absorption rate. (See Sec.
799.5115(h)(5)(vii)(A) of the regulatory text which states that an
infinite dose must be applied to the skin to achieve a steady-state
rate of absorption for calculation of a Kp.) Concerning the units to be
used for short-term absorption rates, EPA does not agree that
expressing short-term absorption data as cumulative amount per area
rather than a rate provides any interpretive advantage. A short-term
absorption rate represents the average absorption over the time
interval during which it is measured. The true rate will usually be
greater than the average rate early in the time interval and less than
the average rate later in the time interval. A determination of
cumulative amount absorbed per unit of area provides only end of the
experiment information rather than information about the average rate
during the course of the test. EPA is requiring that the results be
expressed as a rate (ug/h/cm\2\), rather than as an amount per area
(ug/cm\2\) in order to be consistent with rate units used to calculate
Kp (Ref. 63).
ix. Allowing the use of human skin obtained from cosmetic surgery
(breast and/or abdominal skin) as an alternative to human cadaver skin
for testing. In refining the test method, the ITC and EPA considered
the collective views of commenters, Federal scientists, and
laboratories capable of conducting such testing. The test standard
specifies the use of human cadaver skin which EPA believes makes
efficient use of labor and materials and can easily be performed by
many different laboratories. EPA believes that the use of this human
cadaver skin will provide the desired results in an economical and
timely manner. Although EPA agrees that a method utilizing viable human
skin could provide more reliable Kps for compounds in which skin
metabolism influences dermal penetration, EPA does not believe that
extensive metabolism is likely, based on the physical chemical
properties, for the 34 chemicals subject to this final rule. Based on
the public comments received and discussions with Federal scientists
and laboratories capable of conducting such testing, EPA believes that
performing the study with skin from cosmetic surgery could increase
test costs. As a result, the final test standard requires the use of
human cadaver skin.
x. Not requiring the use of radiolabeled materials in the required
testing because many chemicals subject to the final rule are unlikely
to be readily available in radiolabeled form. Thus, it will take
additional time to prepare an adequate supply of radiolabeled
chemicals, potentially adversely affecting industry's ability to meet
the regulatory deadlines established for completing the testing and
submitting the test results.
EPA disagrees. This comment was in reference to a single chemical
(tetrahydrofuran) and was the only comment which indicated that
radiolabeled materials are not available off-the-shelf. EPA believes
that radiolabeled materials are likely to be available for at least
some of the other chemicals included in this final rule. In those
instances where radiolabeled materials are not currently available and
must be synthesized, EPA believes that the additional amount of time
provided in this final rule (see Unit III.E.2.f.) is sufficient both to
prepare such materials and complete the testing. Also, radiolabeling is
not an uncommon analytical procedure and there are many different
laboratories (Ref. 46) in the United States that are capable of
preparing radiolabeled materials. Finally, the test itself is short-
term, generally taking no longer than 24 hours to complete. The Agency
has provided test sponsors with 13 months to complete the requirements
established under this final rule. To the extent that a test sponsor
does require additional time to comply with the final rule, an
extension from EPA may be requested utilizing the procedures at 40 CFR
790.55.
xi. Deleting the word ``live'' as used in Sec.
799.5115(h)(5)(i)(A) of the proposed regulatory text which states ``the
most accurate absorption rate data for regulatory concerns related to
human
[[Page 22413]]
health would be obtained with live human skin.'' In the course of
developing the final test rule, EPA deleted this statement from the
test standard primarily for the reasons presented in Unit III.E.2.o.ix.
F. Chemical Specific Comments
Chemical specific comments on ethyl ether (CAS No. 60-29-7),
isobutyl alcohol (CAS No. 78-83-1), sec-butyl alcohol (CAS No. 78-92-
2), o-dichlorobenzene (CAS No. 95-50-1), p-nitrotoluene (CAS No. 99-99-
0), beta-chloroprene (CAS No. 126-99-8), n-amyl acetate (CAS No. 628-
63-7), N-isopropylaniline (CAS No. 768-52-5), and o-dinitrobenzene (CAS
No. 528-29-0) are addressed in Unit VII.
1. Acetonitrile. The Acetronitrile Task Force commented that the
total number of workers associated with acetonitrile (CAS No. 75-05-8)
production in the United States is on the order of 500 (Ref. 23). The
Task Force believes that EPA has included laboratory personnel in its
larger estimate as the Agency's figure far exceeds the number of
personnel involved in manufacturing the chemical. The Task Force notes
that analytical laboratory personnel are well trained in safely
handling hazardous materials of this type, and that these workers
typically handle small volumes of acetonitrile.
EPA reviewed the Acetonitrile Task Force's estimate of the number
of workers exposed to acetonitrile at manufacturing sites, but did not
find that the information provided sufficient basis to conclude that
there are not substantial numbers of workers potentially exposed to
acetonitrile during manufacturing, processing, and use. Although EPA
requested the Acetonitrile Task Force to provide documentation for its
estimate of the number of workers exposed to acetonitrile, EPA did not
receive any further information from the Task Force in support of its
estimate. Also, the NOES data used by EPA did include laboratory
personnel and EPA believes it is appropriate to include them because
they are potentially exposed. EPA believes that employee training does
not assure that exposure will not occur and is no basis for the
assertion that laboratory employees will have no exposure. EPA also
believes that the Task Force's estimate that 500 employees are
potentially exposed may be low if it did not include laboratory
personnel. Absent specific data indicating otherwise, EPA believes the
NOES database should be used to estimate worker exposure because it is
the most recent and comprehensive source of this kind of information.
Therefore, EPA is requiring the testing of acetonitrile to determine an
in vitro dermal absorption rate.
2. Carbon disulfide. ACC's Carbon Disulfide Panel cited three
studies summarized in an Agency for Toxic Substances and Disease
Registry (ATSDR) document (Toxicological Profile for Carbon Disulfide
(August 1996), p. 65-66) as a supporting rationale for its assertion
that sufficient data exist for carbon disulfide (CAS No. 75-15-0) and
that testing of carbon disulfide is therefore, unnecessary (Ref. 39).
One 30-year-old study estimated dermal absorption by measuring very
small changes in carbon disulfide solution before and after immersion
of the hand (T. Dutkiewicz and B. Baranowska. 1967. The significance of
absorption of carbon disulfide through the skin in the evaluation of
exposure. Toxicology of Carbon Disulfide. Proceedings of a Symposium,
Prague, 1966, pp. 50-51). EPA reviewed this study and considered the
methodology flawed due to its indirect measurement and potential
failure to control for volatilization. In the other two studies cited
by the Carbon Disulfide Panel (A.E. Cohen, et al. 1958. Skin absorption
of carbon disulfide vapor in rabbits. I. Associated changes in blood
protein and zinc. AMA Archives of Industrial Health, 17:164-169; and H.
Drexler, et al. 1995. Carbon disulfide. 2. Investigations on the uptake
of CS2 and the excretion of its metabolite 2-
thiothiazolidine-4-carboxylic acid after occupational exposure.
International Archives of Occupational Environmental Health, 67:5-10),
EPA notes that a dermal absorption rate was not determined and could
not be derived using the data gathered (Ref. 62).
The Carbon Disulfide Panel also cited a dermal absorption rate
calculated by EPA for carbon disulfide in composted sludge at a level
of 0.59 milligrams per kilogram (mg/kg) soil. EPA notes that the dermal
absorption rate was not experimentally determined, but was estimated
from low environmental levels in composted sludge rather than the
potentially higher worker exposure to the undiluted liquid (Ref. 62).
EPA and OSHA do not consider the data cited by the Carbon Disulfide
Panel to be sufficient to determine a useful and reliable dermal
absorption rate (Ref. 62).
The Carbon Disulfide Panel also cited ATSDR's statement that
``carbon disulfide partitions immediately to the air when released to
the environment, and does not therefore expose humans to carbon
disulfide through oral or dermal contact'' (Toxicological Profile for
Carbon Disulfide (August 1996), pp. 134-141). EPA notes that this
statement refers to dermal contact with environmental media that had
been contaminated with carbon disulfide, not to occupational exposure
(Ref. 62). In fact, the same document makes it clear that the main way
workers are exposed to carbon disulfide is through the inhalation of
vapors and dermal contact (Toxicological Profile for Carbon Disulfide
(August 1996), pp. 9 and 63). Therefore, EPA is requiring the testing
of carbon disulfide to determine an in vitro dermal absorption rate in
this final rule.
3. Naphthalene. ACC's Naphthalene Panel commented that dermal
toxicity data generated under the Federal Insecticide, Fungicide and
Rodenticide Act (FIFRA) makes the [proposed] test rule unnecessary
[with respect to naphthalene] (Ref. 34). The Naphthalene Panel comments
summarize four unpublished studies submitted under FIFRA to support the
registration of naphthalene (CAS No. 91-20-3) as an active ingredient
in moth repellants. One study reports the simulated amount of
naphthalene that would be deposited on the hands of a homeowner
handling mothballs. However, the study did not simulate occupational
exposure and a dermal absorption rate was not measured. The other three
studies were toxicity investigations in which the test compound was
topically applied to animals, but none of the studies measured the rate
of absorption. The toxicity endpoints examined (mortality, body/organ
weights, hematology, gross tissue examination, skin lesions) related to
only dermal irritation or advanced systemic effects (Ref. 62). EPA and
OSHA do not consider the data cited by the Naphthalene Panel to be
sufficient to determine a dermal absorption rate. Therefore, EPA is
requiring the testing of naphthalene to determine an in vitro dermal
absorption rate in this final rule.
The Naphthalene Panel also commented that EPA's proposed test rule
for certain Hazardous Air Pollutants (Ref. 48) estimated that 23,092
workers are exposed to naphthalene, yet, the proposal to this final
rule estimated that 112,695 workers are exposed to naphthalene. In both
proposals, EPA cited the NOES as the basis for the estimates. The
Naphthalene Panel argued that neither figure is correct and that an
informal survey of Naphthalene Panel members, which comprise the major
manufacturers and importers of naphthalene, showed that only
approximately 263 workers are potentially exposed during naphthalene
manufacturing activities in the United States. The Naphthalene Panel
also
[[Page 22414]]
argued that the NOES did not obtain information on the frequency,
concentration, nor duration of worker exposure to naphthalene, and
therefore EPA should not rely on the NOES to find ``substantial'' or
``significant'' worker exposure. Furthermore, although the criteria
stated in EPA's ``B'' policy for finding ``substantial'' human exposure
may be met (Ref. 55, p. 28746), the Naphthalene Panel believes NOES
does not show worker exposure to naphthalene at levels that may cause
health concerns. Moreover, the Naphthalene Panel indicated (without
providing further specific information) that NOES does not reflect
current workplace conditions or naphthalene exposure levels.
EPA acknowledges that different estimates for the numbers of
workers exposed to naphthalene were cited in the two proposed test
rules indicated by the commenter and that these estimates were both
from the NOES. The estimate of 23,092 workers in the Hazardous Air
Pollutants proposal (Ref. 48) was based on an interim report (Ref. 49)
compiled in March of 1989. The NOES database was still being updated
after that time until June 1990, when the final update was completed
and trade name product resolution ceased. The estimate of 112,695
potentially exposed workers cited in the proposal to this final rule
was based on the final update of the NOES. The figure is still the most
up-to-date NOES information EPA has related to potential worker
exposure to naphthalene, which includes employee exposure information
on both manufacturing and processing sites. EPA considered the results
of the Naphthalene Panel's survey of its members which found that 263
workers were potentially exposed at their manufacturing sites. However,
that number does not include an estimate of the number of employees
potentially exposed to naphthalene at processing sites.
As stated in Unit III.B.1.a., it is EPA's belief that the
``substantial'' human exposure finding in TSCA section
4(a)(1)(B)(i)(II) was intended to address situations in which large
numbers of people, in this instance, large numbers of workers, may be
potentially exposed to a chemical substance. EPA is not required to
make a finding that a chemical substance would pose an unreasonable
risk of injury at some hypothetical level of toxicity and exposure in
order to require testing under TSCA section 4(a)(1)(B). See Chemical
Manufacturers Association v. EPA, 899 F.2d 344, 354-55 (5\th\ Cir.
1990). EPA has made the necessary findings under TSCA section
4(a)(1)(B), and EPA is therefore requiring the testing of naphthalene
to determine an in vitro dermal absorption rate in this final rule.
4. Biphenyl. The Biphenyl Work Group (BWG) commented that biphenyl
(CAS No. 92-52-4) currently has two primary uses. Both uses are in
closed systems either as a chemical intermediate or as a component of
thermal fluids in highly specialized, closed industrial heat transfer
systems (Ref. 20). The BWG states that previous industrial uses of
biphenyl in fruit wrappings and as a dye carrier have been phased out.
Therefore they state that any exposure to biphenyl is unlikely. The BWG
asserts that only very low airborne exposures of biphenyl are found in
manufacturing facilities and facilities using heat transfer fluids.
They state that, with reference to the biphenyl occupational exposure
limit of 200 parts per billion (ppb) (29 CFR 1910.1000(a), Table Z-1),
occupational airborne exposures are very low. The BWG estimated that at
present, no more than 100 workers are involved in U.S. biphenyl
production (including maintenance and laboratory personnel) and fewer
than 100 workers have potential dermal exposure in heat transfer uses.
EPA reviewed the BWG's estimate of number of workers exposed to
biphenyl, but did not agree that the information provided sufficient
basis to conclude that there are not substantial numbers of workers
potentially exposed to biphenyl (Ref. 67). Although EPA requested the
BWG to provide documentation for its estimate of the number of workers
exposed to biphenyl, EPA did not receive any further information from
the BWG to support its estimate. Absent specific data indicating
otherwise, EPA believes the NOES database should be used to estimate
worker exposure because it is the most recent and comprehensive source
of this kind of information. Therefore, EPA is requiring the testing of
biphenyl to determine an in vitro dermal absorption rate.
5. p-Xylene, pentane, nonane, and n-heptane. The Hydrocarbon
Solvents Panel states that EPA should be able to reliably determine
dermal absorption rates for untested members of a chemical category by
comparing the logarithms of their octanol-water partition coefficients
(log KOW) to those of structurally similar category members
which have data on dermal absorption rates (Ref. 37).
The Hydrocarbon Solvents Panel did not provide sufficient detail to
evaluate its case for a category approach with these four chemicals.
The Hydrocarbon Solvents Panel also did not provide any data, nor is
EPA aware of any data, which would provide EPA with a reliable estimate
of the dermal absorption rate for p-xylene, pentane, nonane, and n-
heptane. Therefore, EPA is requiring testing of p-xylene, pentane,
nonane, and n-heptane.
6. p-Dichlorobenzene and chlorobenzene. The Chlorobenzene Producers
Association cited a number of acute dermal toxicity studies for p-
dichlorobenzene (CAS No.106-46-7) and chlorobenzene (CAS No. 108-90-7)
to support its position that testing of these chemicals is unnecessary
(Ref. 31). In addition, the Association cited EPA's Dermal Exposure
Assessment: Principles and Applications (Ref. 42), which described
calculated Kps for chlorobenzene and p-dichlorobenzene.
EPA disagrees with the comment that testing chlorobenzene and p-
dichlorobenzene is unnecessary because existing data on dermal toxicity
or calculated Kp values are sufficient to reasonably predict the human
health effects of dermal exposure to these chemicals. None of the
studies cited by the Chlorobenzene Producers Association for
chlorobenzene or p-dichlorobenzene specifically measure the dermal
absorption rate of these chemicals or provide data by which dermal
absorption rate can be determined. The Kp values cited in the 1992 EPA
Dermal Exposure Assessment Report for the two chemicals are estimated
from empirical models and not experimental data and, therefore, do not
meet OSHA needs. Therefore, EPA is requiring testing of chlorobenzene
and p-dichlorobenzene to determine an in vitro dermal absorption rate.
7. Tetrahydrofuran. THFTF commented that quantitative dermal
absorption data for tetrahydrofuran (CAS No. 109-99-9) are not needed
by OSHA to establish its skin designations because OSHA has established
skin designations in the past without such data. THFTF also commented
that ``current MSDS warnings and product stewardship efforts'' are
adequately protective against harmful dermal exposure to
tetrahydrofuran in the workplace (Ref. 32).
OSHA's current skin designations (29 CFR 1910.1000, Table Z-1) were
originally recommendations made by the Threshold Limit Value (TLV)
Committee of the American Conference of Governmental Industrial
Hygienists (ACGIH) in 1970 or prior to 1970, and adopted without
reservation by OSHA in 1971. It is true that OSHA was able to set the
original ``skin designations'' without quantitative dermal absorption
data. However, OSHA currently believes that now and in the future when
a skin
[[Page 22415]]
designation is included in a standard that limits occupational
exposure, it should be supported by a scientific determination of the
ability or speed of the substance to be absorbed through the skin after
dermal contact. Because methods are now available to provide this
information for human skin, OSHA is seeking such testing.
Regarding ``current MSDS warnings and product stewardship
efforts,'' EPA agrees with THFTF that these vehicles have been
important in reducing worker exposures, but they are only as good as
the scientific data on which they are based. To ensure that the
exposure limits endorsed by MSDSs are sufficiently protective, dermal
absorption rate information is needed to better understand the
contribution to total exposure from the dermal route.
8. Dipropylene glycol methyl ether. ACC's Propylene Glycol Ethers
Panel cited a number of acute, subacute, and subchronic toxicity
studies on dipropylene glycol methyl ether (CAS No. 34590-94-8),
including studies via the dermal route, to support the position that
testing this chemical is unnecessary (Ref. 35). None of the studies
described in the Panel's comments specifically measure the dermal
absorption rate of dipropylene glycol methyl ether nor can dermal
absorption rates be derived from the data provided in those studies
(Ref. 64). Therefore, EPA is requiring testing of dipropylene glycol
methyl ether to determine an in vitro dermal absorption rate.
G. Laboratory Capacity
API and THFTF commented that EPA should consider ongoing demands
for laboratory services. API noted that government and industry are
currently involved in many testing projects, including the voluntary
HPV Challenge Program (Ref. 51). API suggested that EPA evaluate
laboratory capacity and the combined demand that multiple testing
programs will create. Likewise, THFTF warned of the possibility that
available laboratory expertise will be overwhelmed by the testing
required in this final rule.
In specifying the in vitro dermal absorption rate test standard for
this rulemaking, EPA concluded that the test standard uses labor and
materials efficiently and can be performed in the manner described by a
variety of laboratories. The Agency has conducted, in addition to the
analysis (Ref. 52) described in the proposal to this rulemaking (Ref.
5), two more recent studies (Refs. 46 and 53) of laboratory capacity
associated with its other chemical testing programs. These two studies
provided further support to EPA's belief that there is sufficient
laboratory capacity to accommodate the testing which is required by
this final rule.
The testing required under this rulemaking is not very complicated.
The in vitro tests are of short duration, generally taking no longer
than 24 hours to complete. The Agency has provided test sponsors with
13 months to complete the requirements established under this final
rule. EPA does not believe that the relatively modest amount of new
testing required (a total of three tests on each of 34 chemicals) will
exceed the available laboratory capacity, particularly given the short-
term nature of the testing, the relatively low cost of the tests, and
the long time period allowed for completing the studies. Furthermore,
based on the analyses developed by EPA (Refs. 46, 52, and 53), EPA does
not believe the cumulative impacts associated with a variety of its
existing chemical testing programs is likely to overwhelm the available
laboratory expertise as suggested by API and THFTF.
H. Export Notification
Several issues raised in comments relate to EPA's implementation of
TSCA section 12(b) (15 U.S.C. 2611(b)) export notification requirements
for chemicals for which the submission of data is required under TSCA
section 4. Section 12(b) of TSCA states, in part, that any person who
exports or intends to export to a foreign country a chemical substance
or mixture for which the submission of data is required under TSCA
section 4 must notify the EPA Administrator of such export or intent to
export. The Administrator in turn will notify the government of the
importing country of EPA's regulatory action with respect to the
substance. EPA's regulations implementing TSCA section 12(b) are at 40
CFR part 707, subpart D.
As a general matter, comments on the scope of EPA's regulations
under TSCA section 12(b) are beyond the scope of this rulemaking.
However, three comments associated with the requirements under TSCA
section 12(b) do merit some discussion in this preamble.
1. Application to chemical in any form. ACC commented that EPA's
statement in its proposed rule that export notification requirements
would apply to exporters of the chemical substances subject to the
final rule regardless of the form (e.g., byproduct, impurity) in which
they are exported constitutes an unprecedented expansion of the TSCA
section 12(b) notification requirements.
EPA disagrees with this comment. TSCA section 12(b) and the
implementing regulations at 40 CFR part 707 apply, in part, to the
export or intended export of a chemical substance for which the
submission of data is required under TSCA section 4. Neither the
statutory nor the regulatory language restricts this requirement to
exporters of chemical substances and mixtures in particular forms, but
instead generally extends export notification requirements to exporters
of chemical substances and mixtures without regard to the form in which
the chemical substances and mixtures are being or will be exported. The
language in the proposed rule and in this final rule are not an
expansion of the TSCA section 12(b) notification requirements. It is
noted, however, that the Agency did not intend to change the current
export notification provisions affecting articles which specify that no
export notification is required for articles, except polychlorinated
biphenyl articles, unless required in specific section 5, 6, or 7
rules. See 40 CFR 707.60(b).
2. Exporters subject to notification requirement. ACC states that
TSCA section 12(b) limits the imposition of export notification
requirements related to TSCA section 4 actions to persons who actually
have testing obligations under TSCA section 4. EPA disagrees. TSCA
section 12(b)(1) and the implementing regulations at 40 CFR part 707,
subpart D apply to any person who ``exports or intends to export to a
foreign country a chemical substance or mixture for which the
submission of data is required under [TSCA section 4].'' (15 U.S.C.
2611(b)(1)). Under 40 CFR 707.65(a)(2)(ii), exporters must notify EPA
of their first export or intended export to a particular country when
data are required under TSCA section 4. EPA believes the language
unambiguously requires notification of export by exporters of
substances which are the subject of TSCA section 4 actions regardless
of whether the exporters themselves are also subject to the underlying
TSCA section 4 rules. Thus, exporters of a chemical substance that is
covered by data submission requirements under TSCA section 4, including
persons who are not otherwise subject to the TSCA section 4 rule itself
as manufacturers and/or processors, are subject to export notification
requirements under TSCA section 12(b).
3. Information collection request (ICR). API suggests that, because
this final rule will result in the requirement that export
notifications are submitted to EPA for exports or intended exports
[[Page 22416]]
of the substances covered by the final rule, this is a new information
collection activity that requires OMB review (Ref. 19). Furthermore,
API believes that EPA's cost estimates for TSCA section 12(b)
notification ignores the biggest costs associated with export
notification, which are the internal training and systems necessary to
identify exports against the export notification list, tracking of what
notifications have already been submitted and to what countries, and so
forth. These system costs are magnified when business operations change
(e.g., sales, acquisitions, and so forth) and export notification
systems need to be adjusted accordingly.
EPA disagrees that this action is a new collection of information
requiring OMB review. The information collection activities related to
export notification under TSCA section 12(b)(1) are approved under OMB
control number 2070-0030 (EPA ICR No. 0795). The methodologies,
assumptions, and estimates developed by EPA for implementation of TSCA
section 12(b) have been reviewed under notice and comment procedures
during the development of the ICR. EPA believes it would be more
appropriate to address API's burden concerns in the context of the ICR
renewal process and therefore will not respond to them in the context
of this final rule.
I. Persons Required to Test
EPA stated in the proposed rule that manufacturers and processors
of the chemical substances included in the final rule would be subject
to the final rule. As in the past, under the procedures set forth at 40
CFR part 790, the persons subject to the final rule fall into one of
two groups, designated here as Tier 1 and Tier 2. Persons in Tier 1
(those who would initially have to comply with the final rule) would be
obligated either to: Submit to EPA letters of intent to conduct
testing, conduct this testing, and submit the test data to EPA or apply
to and obtain from EPA exemptions from testing. Persons in Tier 2
(those who would not have to initially comply with the final rule)
would not need to take any action unless they are notified by EPA that
they are required to do so. Persons in Tier 1 who obtain exemptions and
persons in Tier 2 would nonetheless be subject to providing
reimbursement to persons who actually conduct the testing.
Under 40 CFR part 790, EPA traditionally has treated the following
persons as being in Tier 2 in TSCA section 4(a) test rules:
Processors (40 CFR 790.42(a)(2)).
Manufacturers of less than 500 kg (1,100 lbs)
per year (``small-volume manufacturers'') (40 CFR 790.42(a)(4)).
Manufacturers of small quantities for research
and development (``Research and Development (R&D) manufacturers'') (40
CFR 790.42(a)(5)).
In the proposed test rule, EPA reconfigured the tiers in 40 CFR
790.42 by adding the following persons to Tier 2: Byproduct
manufacturers; impurity manufacturers; manufacturers of naturally
occurring substances; manufacturers of non-isolated intermediates; and
manufacturers of components of Class 2 substances. The Agency also
proposed that persons who do not know or cannot reasonably ascertain
that they are manufacturing or processing the chemical substances
included in the final rule would not be subject to the final rule.
EPA's proposed approach to the ``persons required to test'' portion
of this test rule was intended to clarify subject entities' obligations
under the final rule and focus the testing requirements initially on
those entities whom EPA believes would be most likely to conduct
testing (Ref. 5, pp. 31080-31082). EPA solicited comment on this new
approach to the ``persons required to test'' portion of the test rule,
and received a number of comments. After considering these comments,
EPA has decided to finalize the approach as proposed, with the addition
of provisions related to the ``subtiering'' of Tier 2 entities (see
Ref. 5, pp. 31081-31082, and Unit III.I.3.).
1. General agreement with EPA's ``persons required to test''
approach. All the commenters on the new approach to the ``persons
required to test'' section of the proposed rule agreed that
manufacturers of byproducts and impurities and processors are
appropriately placed in Tier 2. These commenters also agreed that the
persons EPA has put in Tier 1 are appropriately placed in Tier 1. API
stated that the approach in the proposed rule ``appropriately focuses
the rule, will reduce burden and complexity, and will facilitate timely
accomplishment of testing.'' API also agreed with the Agency's
rationales for tiering. AFPA stated that the new ``persons required to
test'' approach would provide greater certainty to people about what
they must do under the final rule.
ACC/O and ACC/KO additionally agreed with the inclusion of
manufacturers of components of Class 2 substances in Tier 2. API agreed
with the exclusion of manufacturers or processors who do not know or
cannot reasonably ascertain that they are manufacturing or processing a
test rule substance.
2. EPA should retain the ability to move Tier 2 groups to Tier 1.
AFPA, ACC/O, and ACC commented that EPA should retain the flexibility
to move Tier 2 groups to Tier 1 on a case-by-case basis. For example,
if certain processing activities cause special risks, then processors
could be brought into Tier 1 upfront in the proposed rule. If case-
specific justifications exist for moving Tier 2 entities to Tier 1, EPA
should state these justifications publicly.
EPA agrees that the Agency should retain the ability to elevate
Tier 2 entities to Tier 1 on a case-specific basis in future test
rules, and where the Agency takes such an action, it will state its
justification(s) for doing so. For example, if EPA is able to determine
that a chemical is manufactured solely or primarily in the form of a
byproduct, EPA may propose to include persons who manufacture that
chemical as a byproduct in Tier 1, even though byproduct manufacturers
of other chemicals listed in the same proposed rule might otherwise be
included in Tier 2. EPA does not agree, however, that risk should be a
basis for moving entities from Tier 2 to Tier 1 (see Unit III.I.4.).
EPA will continue to retain flexibility over the status of entities
covered by Tier 2 consistent with EPA's flexibility over the narrower
group of entities that have been included in Tier 2 in previous test
rules; processors, small-quantity manufacturers (i.e., manufacturers of
less than 500 kg (1,100 lbs.) of a test rule chemical), and R&D
manufacturers (40 CFR 790.42(a)(2), (a)(4), and (a)(5), respectively).
In the final rule which established the general Tier 2 status of small-
quantity and R&D manufacturers and processors in test rules, EPA stated
that it ``reserves the right to differ from the general procedure in
this final rule by proposing in a specific TSCA section 4 test rule to
require R&D manufacturers and/or small-quantity manufacturers to submit
exemption applications'' (Ref. 69, p. 18882). EPA will also continue to
retain the ability to elevate, on a case-specific basis, R&D
manufacturers, small-quantity manufacturers, and processors, from Tier
2 to Tier 1. The concept that flexibility can be built into test rules
in general is suggested by 40 CFR 790.2, which states in part that
``the procedures for test rules are applicable to each test rule in
part 799 of this chapter unless otherwise stated in specific test rules
in part 799 of this chapter.''
The Agency does not intend to specifically identify all individual
Tier
[[Page 22417]]
2 entities. Rather, these entities would self-identify via the
submission of letters of intent to test or exemption applications. EPA
expects that, similar to the arrangements typically developed when Tier
1 entities are under an obligation to conduct testing, if Tier 2
entities are required to conduct testing, it would generally be to
their benefit to reach agreement on who will actually conduct the
testing. The Agency believes that it is unlikely that Tier 2 entities
will be required to conduct testing under this final test rule, a view
that is shared by ACC which stated that:
[ACC] is not aware of any substance covered by the testing
proposal for which there is likely to be no Tier 1 producer who
comes forward [to conduct testing]. Indeed, ACC is not aware of any
instance in the past where not a single person initially required to
comply with a test rule came forward, such that EPA was required to
notify other persons of their obligations under the test rule.
EPA intends to follow the procedures laid out in the regulatory
text if it becomes necessary for EPA to call upon persons in Tier 2 to
conduct testing. In other words, if EPA does not receive a letter of
intent to test from any Tier 1 entities, the Agency will publish a
Federal Register notice to alert Tier 2 entities to the requirement
that they submit letters of intent to test or exemption applications.
3. Do not subdivide Tier 2 as a general matter, instead subdivide
Tier 2 on a case-by-case basis. In the proposed rule, EPA solicited
comments on subdividing Tier 2 to enable the Agency to prioritize which
persons in Tier 2 would be required to perform testing, if needed. ACC
and API suggested that EPA should not subdivide Tier 2 entities as a
general matter, for all test rules. They commented that, if EPA
considers requiring Tier 2 entities to conduct testing, the Agency
should first determine whether in fact there are no Tier 1 entities,
and reevaluate whether the proposed testing is still necessary. If Tier
1 manufacturers do not conduct testing and the testing is still
necessary, then EPA should identify upfront which persons in Tier 2
will be required to test. ACC suggests that subtiering the Tier 2
entities could be done on a case-by-case basis as needed, based on the
activities that give rise to the need for testing. API argues that
there is no basis for distinguishing processors from the various types
of manufacturers included in Tier 2, therefore there is no
justification for subtiering the Tier 2 entities.
Despite these comments, and although EPA does not anticipate a need
for Tier 2 entities to conduct testing under this final rule, EPA has
decided to subdivide the Tier 2 entities upfront in this final rule
(see Unit V.E.3.e.). Subdividing Tier 2 upfront in test rules may
facilitate compliance by requiring Tier 2 manufacturers, when required
to comply, to submit letters of intent to test or exemption
applications before processors are called upon to do so. The Agency's
expectation is that it may generally be less administratively complex
for manufacturers to conduct the testing (including coordinating
efforts to determine who will actually conduct testing) than for
processors to do so. This is because there are generally fewer
manufacturers (even as byproducts, impurities, etc.) than processors.
EPA also believes that testing costs have traditionally been passed by
manufacturers along to processors, and has not received evidence to the
contrary. The Agency does not believe at this time that it can justify
a subdivision of Tier 2 entities other than between Tier 2
manufacturers and processors. For example, EPA does not believe it
would be appropriate to base a subdivision on the activities that give
rise to the need for testing (see, e.g., Unit III.I.7.).
4. Persons who solely manufacture and/or process non-isolated
intermediates or naturally occurring substances should not be subject
to rules under TSCA section 4. Commenters provided several reasons for
completely exempting these manufacturers from test rule coverage.
Certain commenters believe that these entities have never been covered
by test rules in the past, and were specifically excluded under the
amended proposed rule for hazardous air pollutant (HAP) chemicals (Ref.
70). These commenters pointed out that non-isolated intermediates are
exempt from Premanufacture Notification (PMN), the Inventory Update
Rule (IUR), PAIR, and general TSCA section 8(a) requirements. One
commenter indicated that production of non-isolated intermediates does
not contribute to the need for testing or present the same concerns as
do other substances introduced into commerce, thus manufacturers of
non-isolated intermediates should not be considered subject to test
rules. Another commenter suggested that EPA has discretion under TSCA
section 4 to specify the classes of persons subject to or exempt from a
test rule based on its rationale for requiring testing. The comments
suggest, however, that where EPA has case-specific justification(s)
(for example, chemical-specific hazard or exposure concerns related to
the manufacture of non-isolated intermediates or naturally occurring
substances are demonstrated), these categories of manufacturers could
be appropriately included as subject to a rule.
EPA does not believe that it would be appropriate to fully exempt
manufacturers and processors of non-isolated intermediates and
naturally occurring substances from rules under TSCA section 4.
Instead, it is generally appropriate to include such entities as
persons subject to TSCA section 4 test rules because they are
considered manufacturers and processors under TSCA and should be
included among those responsible for conducting testing or providing
fair and equitable reimbursement to those who have conducted testing.
As a general matter, however, EPA intends to place manufacturers of
non-isolated intermediates and naturally occurring substances in Tier 2
in test rules unless, for example, the Agency believes such
manufacturers are responsible for a disproportionate share of the
production volume of a test rule substance, in which case EPA may place
them in Tier 1.
The plain language of the statute indicates that testing
responsibilities under TSCA section 4(b)(3)(B) are not restricted to
those who manufacture or process a test rule chemical for limited uses.
Nor is EPA required to demonstrate that particular types of
manufacturing or processing contribute to the need for testing (i.e.,
that a particular type of manufacture plays a direct role in increasing
risk, in the case of a rule based on a TSCA section 4(a)(1)(A) finding,
or in increasing exposure, in the case of a rule based on a TSCA
section 4(a)(1)(B) finding). See TSCA section 4(a). The statute
indicates that if EPA finds that the effects associated with
manufacture, distribution in commerce, processing, use, or disposal
cannot reasonably be determined or predicted (see TSCA section
4(a)(1)(A)(ii) and 4(a)(1)(B)(ii)), then manufacturers and/or
processors are generally required to test (see TSCA section
4(b)(3)(B)). For example, the final TSCA section 4 rule for biphenyl
(Ref. 77, pp. 37184-37185) stated that TSCA section 4 testing
responsibilities are not restricted to only those who manufacture or
process a test rule chemical for certain uses. Rather, the persons who
manufacture and/or process (depending on the findings made) a test rule
chemical are generally subject to the requirements of a final test
rule.
In order to ensure that reimbursement of the entity(ies) conducting
testing is equitable, as a general matter, EPA does
[[Page 22418]]
not believe that it is appropriate for classes of entities otherwise
potentially subject to a rule to be dropped from all rule-related
obligations (with the exception of persons who do not know or cannot
reasonably ascertain that they manufacture or process a test rule
substance). There may be circumstances, not present here, when it would
be equitable to exempt additional entities from all test rule
obligations, but that determination would need to be made on a case-by-
case basis.
Persons who solely manufacture a chemical in the form of a non-
isolated intermediate are generally exempt from the TSCA section 5 PMN
regulations (40 CFR 720.30(h)(8)), the TSCA section 8(a) IUR (40 CFR
710.30(c)), the TSCA section 8(a) PAIR (40 CFR 712.25(d)(2)), and the
general TSCA section 8(a) regulations (40 CFR 704.5(d)) for reasons
particular to those regulations. However, this does not preclude EPA
from treating these persons as manufacturers of chemical substances for
purposes of other provisions of TSCA, including TSCA section 4. For
example, EPA has stated that:
chemical substances [which are not intentionally removed from
the equipment in which they were manufactured] are considered to be
manufactured or processed for a commercial purpose for the purposes
of section 8 of the Act.
(Ref. 71, p. 64588).
EPA believes it is generally appropriate to include manufacturers of
non-isolated intermediates and naturally occurring substances as
persons subject to TSCA section 4 test rules in order to ensure that
reimbursement of those who paid the costs of testing is equitable. TSCA
section 4(c)(3)(A) requires EPA to order ``fair and equitable''
reimbursement for test costs under the Agency's reimbursement
regulations. Consistent with this purpose, EPA's current ``persons
required to test'' approach distributes the burden of testing and
reimbursement equitably among the persons who manufacture and/or
process test rule substances, with an exemption for persons who do not
know or cannot reasonably ascertain that they manufacture or process a
test rule substance.
Even if it were relevant to the question of who is subject to a
TSCA section 4 test rule, EPA disagrees with the assertion that the
manufacture of non-isolated intermediates does not present any
exposure-related concerns. While the amount of chemical substance
released as a result of this type of production may generally be
expected to be less than is released as a result of other production,
manufacturing or processing a chemical as an intermediate does not
preclude exposure to that chemical. See Office of Solid Waste final
test rule (Ref. 72, p. 22305). The production of non-isolated
intermediates presents concerns related to acute exposures, from, e.g.,
spills, leaks or transfers. In addition, as EPA stated in the test rule
for Office of Solid Waste chemicals:
It is common experience that process waste streams and reactor
vessel residues will contain ``intermediates.'' In many instances,
these chemicals are released to the environment as fugitive
emissions, liquid or solid wastes, and as unreacted feedstock
(impurities) in finished products. As such, ``intermediates''
typically exist as chemicals to which there is potential for human
exposure.
(Ref. 72, p. 22305).
EPA believes that, although a person's manufacture of a chemical in
the form of a non-isolated intermediate may provide a lesser exposure
concern than the manufacture by other persons of the same chemical in
other forms, an appropriate accounting of responsibility is provided
for in the determination of fair and equitable reimbursement under
TSCA, when necessary. TSCA section 4(c)(3)(A) states that ``all
relevant factors'' must be considered by EPA in the promulgation of
rules for the determination of reimbursement. Pursuant to this
provision, EPA established mechanisms in its general reimbursement rule
to allow, as needed, for the case-specific consideration of factors
such as exposure to a chemical as a result of each subject person's
manufacturing and/or processing activities. See 40 CFR 791.40(a).
Finally, manufacturers and processors of non-isolated intermediates
and naturally occurring substances have been subject to test rules in
the past, except as proposed in the amended proposals for the testing
of certain hazardous air pollutants (HAPs). (Ref. 73, pp. 19696, 19699
and Ref. 70, pp. 67470, 67481). EPA is not adopting the approach taken
in the HAPs proposals for this final rule and, as described in Unit
V.E., is taking a different position here. TSCA section 4(a) requires
testing if findings have been made with regard to certain activities
involving chemical substances or mixtures, and, under TSCA section
4(b)(3)(B), manufacturers and/or processors must conduct such testing
if findings have been made. TSCA does not distinguish among
manufacturers and processors of different forms/production types of a
chemical substance or mixture; all are generally subject to the
requirements of TSCA section 4.
5. ``Manufacturers of test substances as components of Class 2
substances'' should not be included among the persons subject to the
final rule. In the proposed rule, EPA stated that manufacturers of test
substances as components of Class 2 substances would be among those
entities that would be subject to the final rule, but not initially
required to comply (i.e., Tier 2). Class 2 substances are chemical
substances having a chemical composition that cannot be represented by
a specific, complete chemical structure diagram, because such a
substance generally contains two or more different chemical species
(not including impurities) (see 40 CFR 720.45(a)(1)(i)). The Agency
received a number of comments debating the appropriateness of the
proposed Tier 2 status of manufacturers of components of Class 2
substances.
a. ACC and API (Refs. 15 and 19) commented that components of Class
2 substances are not considered under TSCA to have been
``manufactured'' in their own right unless they have been separated
from the Class 2 substance.
EPA disagrees. The Agency considers a substance to be manufactured
for purposes of TSCA section 4 even if it is manufactured as a
component of another chemical substance, and regardless of its
isolation from other components of the combination. EPA maintains that
to be regulated under a TSCA section 4 action (for which findings have
been made that allow EPA to cover manufacturers), a manufacturer must
be a ``manufacturer'' as defined by TSCA section 3, and manufacture a
chemical substance (or mixture) that is subject to a test rule. Under
TSCA section 3(7):
[t]he term `manufacture' means to import into the Customs
territory of the United States (as defined in general headnote 2 of
the Tariff Schedules of the United States), produce, or manufacture.
There are no limitations in the definition of ``manufacture'' or in
TSCA section 4 to suggest that if a person imports, produces, or
manufactures a test rule substance as part of a complex combination of
substances (i.e., a Class 2 substance), as opposed to an isolated
component, then the person is not a manufacturer of that test rule
substance. Therefore, EPA considers a chemical substance to be
manufactured and subject to coverage under TSCA section 4 even if it is
manufactured as a component of another chemical substance, and
regardless of its isolation from other components of the combination.
[[Page 22419]]
EPA has used the term ``Class 2 substance'' as a way to describe
variable composition substances and complex combinations of substances
which can separately be considered ``chemical substances'' under TSCA.
If a Class 2 substance is a chemical substance as defined by section
3(2)(A) of TSCA, then EPA may regulate the Class 2 substance itself.
Neither the designation of a particular substance as a Class 2
substance, nor EPA's authority to regulate it as a distinct chemical
substance under the Act, changes the fact that it may contain any
number of individual components which may also be ``chemical
substances'' as defined by TSCA, and therefore, also be subject to
EPA's regulatory authority under the Act. See, especially, TSCA section
3(2)(A), which identifies among the set of substances that are
``chemical substances'':
. . . any organic or inorganic substance of a particular
molecular identity, including any combination of such substances
occurring in whole or in part as a result of a chemical reaction or
occurring in nature. . .
Thus, if appropriate TSCA section 4(a)(1) findings are made with regard
to manufacturing, distribution in commerce, use, and/or disposal
activities for a chemical substance, then manufacturers of that
substance are subject to the test rule according to TSCA section
4(b)(3), regardless of whether they manufacture the substance as a
component of a Class 2 substance or in some other manner.
This is consistent with the position set forth in the proposed
methylcyclopentane (MCP) and commercial hexane test rule, stating that:
. . .manufacturers and processors of MCP or commercial hexane
who do so in the course of producing gasoline or other motor or
heating fuels are subject to this rule because the Agency's. .
.findings are based on the manufacture, processing, and use of MCP
and commercial hexane.
(Ref. 75, p. 17864-17865).
Gasoline is a Class 2 substance; commercial hexane is a Class 2
component of gasoline and MCP is one of its C6 isomer
components. In the final rule, EPA dropped the testing requirement for
MCP, but kept the requirement for manufacturers of commercial hexane,
stating that ``[i]f health effects are positive for commercial hexane,
then EPA may consider testing the C6 components
individually'' (Ref. 76, pp. 3387-3388).
The Agency acknowledges that it has not explicitly required persons
who manufacture test substances as components of Class 2 substances to
comply with certain test rules in the past. However, the Agency does
believe that these persons are manufacturers for purposes of TSCA
section 4, and hence are subject to test rules where appropriate
findings are made under TSCA sections 4(a)(1) and in accordance with
TSCA section 4(b)(3).
b. ACC (Ref. 15) commented that EPA should clarify that it will
continue to treat Class 2 substances as distinct chemical substances
(with components that are not regulated under the PMN and other TSCA
regulations) regardless of the ``persons required to test'' approaches
taken in the OSHA dermal and HAPs proposed rules.
The approach to the identification of ``persons required to test''
that is being adopted in this final test rule, and which may be applied
in other, future test rules, is not intended to modify the status of
any chemical substance or entity under other existing TSCA regulations.
c. API (Ref. 19) commented that Tier 2 should include
``manufacturers of Class 2 substances that contain a test rule
substance'' rather than ``manufacturers of components of Class 2
substances.''
EPA disagrees with this suggested change, and has not implemented
it in this final rule. The Agency believes it has the authority under
TSCA section 4 to regulate both manufacturers of Class 2 substances
themselves (for example, by requiring the testing of a Class 2
substance by manufacturers of that Class 2 substance) and manufacturers
of test substances as components of Class 2 substances (for example, by
requiring the testing of a chemical substance by manufacturers that
produce or import that chemical substance as a component of a Class 2
substance). In this final test rule, persons in the former group are
included in Tier 1 of the grouping of persons required to test, whereas
persons in the latter group are included in Tier 2.
d. API (Ref. 19) commented that manufacturers of Class 2 substances
should not be considered manufacturers of the myriad components in the
Class 2 substances unless they isolate a component chemical, for a
number of reasons:
Class 2 substances are distinct chemical
substances that are complex and variable in composition, and the Class
2 nomenclature is accurate and useful for representing them.
A Class 2 stream may contain a substance as a
component at some times but not at others.
Applying TSCA rules to Class 2 substances,
rather than to their individual components, does not compromise
protection of human health and the environment.
Because many components of Class 2 substances do
not add commercial value to the products, manufacturers of Class 2
substances may not be aware of the presence of test rule substances as
components.
As stated in Unit III.I.5.a., EPA does not agree that manufacturers
of components of Class 2 substances should only be regulated under TSCA
section 4 if they isolate a component substance that is subject to the
test rule. TSCA section 4(b)(3)(B) generally provides the authority for
the Agency to include all manufacturers and/or processors in the scope
of test rules, regardless of whether they isolate a test rule substance
from a Class 2 substance.
The inclusion of manufacturers of test substances as components of
Class 2 substances as persons subject to this final test rule is not
intended to reflect any finding, or determination on the part of EPA
that there is a direct connection between a specific manufacturing
activity and the potential human health and/or environmental hazards or
risks that may be associated with the test rule substance. See also
biphenyl final test rule (Ref. 77, pp. 37184-37185). Their inclusion as
persons subject to the rule is intended to facilitate the fair and
equitable distribution of burden of testing and reimbursement among the
persons who manufacture and process test rule substances. For example,
there may be cases where large quantities of a component of a Class 2
substance are manufactured, such that the quantity of a particular non-
isolated component (that is the subject of a TSCA section 4 test rule)
is far greater than the quantity of the same chemical substance
manufactured in isolated form by other persons.
The concern that ``because many components of Class 2 substances do
not add commercial value to the products, manufacturers of Class 2
substances may not be aware of the presence of test rule substances as
components'' is addressed by the provision in this final test rule
which exempts persons from testing obligations where their status as
manufacturers or processors of a particular substance is not ``known to
or reasonably ascertainable by'' them.
In response to the comment noting that persons may be aware of the
presence of a component of a Class 2 substance in a stream at some
times but not others, EPA believes that the reimbursement process under
TSCA
[[Page 22420]]
section 4 and the implementing regulations at 40 CFR part 791 address
the concern; under these provisions, if utilized, persons would be
required to provide fair and equitable contributions to test costs. The
circumstance of a substance that is known to be produced at only
certain times and not others may be a consideration under that process.
e. API (Ref. 19) commented that requiring manufacturers of Class 2
substances to test components of Class 2 substances that are also test
substances would be a departure from past regulatory practice under
TSCA section 4.
EPA disagrees with the commenter's statement that requiring
manufacturers of Class 2 substances to test components that are also
test substances that the person manufactures would be a departure from
past regulatory practice under TSCA section 4. EPA acknowledges that in
general its past practice has not been to impose explicit obligations
under TSCA section 4 on persons who manufacture a test substance as a
component of a Class 2 substance, unless that person isolates the test
substance from the Class 2 substance, although as discussed in Unit
III.I.5.a., there have been exceptions.
However, EPA did not explicitly require testing by manufacturers of
test substances as components of Class 2 substances in certain previous
test rules in part because EPA had determined in light of comments
received on the proposals that testing of the Class 2 substance itself
would be more appropriate than requiring testing on the individual
components of Class 2 substances. See the discussion of the commercial
hexane test rule (Ref. 76) in Unit III.I.5.a. In another case, EPA
declined to require testing by manufacturers of components of Class 2
substances in a final test rule because it believed that it had
provided insufficient notice that such manufacturers would be subject
to the test rule. See the clarification to the final test rule covering
certain ``Office of Water chemicals'' (Ref. 78).
As discussed previously, however, TSCA sections 4(c)(3)(A) and
4(c)(4)(A) require EPA to order, where necessary, ``fair and
equitable'' reimbursement from manufacturers and processors for test
costs incurred by those who are developing, or who have submitted the
required test data. EPA believes that fairness and equity can be best
facilitated by including within the pool of persons from whom
reimbursement can potentially be sought all persons who can be
considered manufacturers or processors under TSCA, subject to narrow,
clear exemptions. EPA believes that persons who manufacture test
substances as components of Class 2 substances are ``manufacturers''
under TSCA section 4, and generally should not be exempt from inclusion
among those from whom reimbursement could potentially be sought.
6. Create a de minimis exemption. API suggests that EPA provide a
de minimis exemption like the exemption provided in the amended
proposed HAPs rules (Ref. 70, pp. 67470, 67481 and Ref. 73, pp. 19696,
19699) for manufacturers and processors who solely manufacture or
process test rule chemicals in amounts less than 1% in a mixture.
EPA is not adopting this suggestion in this final rule. The final
rule contains an exemption from all responsibilities associated with
the final rule for persons who do not know or cannot reasonably
ascertain that they manufacture or process a test rule substance. The
final rule also provides Tier 2 status to manufacturers of small-
quantities (less than 500 kg/1,100 lb per year or solely for R&D),
those who manufacture the test substance as a byproduct, impurity,
naturally occurring substance, non-isolated intermediate, or component
of a Class 2 substance, and all processors. With respect to
manufacturers of small quantities who manufacture the test substance as
a component of a Class 2 substance, the 500 kg/1,100 lb cutoff applies
to the manufacture of the test substance, not the Class 2 substance.
EPA believes that these provisions supply sufficient relief from test
rule requirements to lower volume manufacturers and processors. These
groups are still subject to reimbursement, however, and they would also
potentially be subject to testing.
To the extent that persons who manufacture a test rule chemical in
amounts less than 1% in a mixture are not covered by the ``known to or
reasonably ascertainable by'' exemption, and are not otherwise included
in Tier 2, they are initially required to comply with the final test
rule. EPA believes that Tier 1 status is appropriate for these
manufacturers, who produce or import at least 500 kg/1,100 lb of a test
rule chemical each year, and who know (or who could reasonably
ascertain) that they are manufacturing the chemical.
7. In determining who is responsible for conducting testing, EPA
should consider the data needs the rule is intended to fill and the
role of specific manufacturing and processing activities in creating
the exposure scenarios the rule is intended to evaluate. ACC commented
that under TSCA section 4(b)(3)(B), responsibility for conducting
testing may be imposed on those manufacturers and/or processors engaged
in activities for which EPA has determined that available data and
experience are insufficient under TSCA section 4(a). Thus, EPA's
approach to the ``persons required to test'' section in a given test
rule should depend on the data needs the rule is intended to fill, and
the role of the specific manufacturing and processing activities in
creating the particular human or environmental exposure scenarios which
the rule is intended to evaluate.
TSCA does not limit the persons subject to a test rule solely to
specific classes of manufacturers and/or processors based on the data
needs the rule is intended to fill, or based on the role of the
specific manufacturing and processing activities in creating particular
exposures. Rather, persons who manufacture and/or process (depending on
the findings made) a test rule chemical are generally subject to the
requirements of the test rule. TSCA section 4(b)(3)(B). See also
biphenyl final test rule (Ref. 77, pp. 37184-37185), which states that
testing responsibilities under TSCA section 4 are not restricted to
only those who manufacture or process a test rule chemical for certain
uses.
EPA agrees that certain limited exemptions for persons who would
otherwise be subject to test rules may be appropriate. However, in
order to fully exempt a group of persons otherwise covered by a test
rule from responsibilities under the test rule, EPA's view is that
there must be an adequate justification for doing so that is consistent
with the intent of the statute, and that is applicable only to those
persons who it is proposing to exempt, and not any others. For example,
in this final rule EPA is exempting manufacturers and processors who
``do not know or cannot reasonably ascertain'' that they are
manufacturing or processing a test rule chemical (see Sec.
799.5115(b)(2) of the regulatory text).
Exempting individual entities or classes of entities from test rule
requirements on the basis of a determination that their activities do
not relate in some direct way to the data needs the rule is intended to
fill or to the exposure scenarios addressed by the rule is not
consistent with the intent of the statute. Such exemptions would likely
result in the need for multiphase rulemaking, and may in most cases not
be possible from a practical standpoint given that EPA often would not
have enough information to make such determinations. In addition,
exempting
[[Page 22421]]
certain individual entities or classes of entities from test rule
requirements increases the potential that the burden of testing and
reimbursement would be distributed in an inequitable manner among the
persons who manufacture and process test rule substances. The Agency
believes it is appropriate to generally require manufacturers and/or
processors of a test rule chemical to be subject to a rule, rather than
to fully exempt individual manufacturers or processors or certain
classes of manufacturers or processors from test rule responsibilities.
8. Tier 2 should not be subject to reimbursement. AFPA, API, ACC/O,
ACC/KO, and ACC commented that subjecting Tier 2 entities to
reimbursement would, in large part, eliminate the benefit associated
with having a tiered approach. EPA should only require Tier 2 entities
to reimburse if they are required to conduct testing in the absence of
testing commitments from Tier 1 entities.
EPA does not agree. In order to ensure that test sponsors have the
ability to seek equitable reimbursement, Tier 2 entities are subject to
reimbursement regardless of whether the entities included in Tier 1
complete the testing required under the rule. EPA addressed this issue
in the context of its May 7, 1990 rule amending the testing procedural
rule by adding certain groups of manufacturers to Tier 2. EPA stated
the following in the final rule:
Some commenters suggested that chemicals produced solely for R&D
[research and development] purposes should be excluded altogether
from TSCA section 4 rules. Thus, rather than placing R&D
manufacturers in a ``second tier,'' they would not be legally
subject unless specified in a particular test rule... EPA does not
believe that it should grant a total exemption to R&D manufacturers.
TSCA section 4 gives EPA authority to require testing of chemicals
manufactured for R&D. Congress did not exempt R&D manufacturers from
being subject to TSCA section 4, as in the case of [rules under]
sections 5 or 8 of TSCA. In this rule, EPA has lifted the procedural
burden imposed on R&D manufacturers by test rules, recognizing that
test sponsors would rarely, if ever, seek reimbursement from R&D
manufacturers. By maintaining legal authority over R&D
manufacturers, however, EPA has reserved the right of a test sponsor
to seek reimbursement from all persons legally subject to a test
rule.
(Ref. 69, p. 18883).
The final rule amending the testing procedural rule indicates that
persons in Tier 2 are subject to the requirement to conduct testing
under a test rule during the period from the effective date of the test
rule to the end of the reimbursement period, but will not generally be
required to submit letters of intent to test or exemption applications
unless no other manufacturer of the chemical submits a letter of intent
to test (Ref. 69, p. 18882). In addition, persons in Tier 2 will be
required to submit letters of intent to test or exemption applications
if a problem occurs with the initiation, conduct, or completion of the
required testing or the submission of the required data with respect to
a chemical substance included in the test rule.
However, although Tier 2 entities are subject to providing
reimbursement, EPA's experience under previous test rules has been that
persons who manufacture the largest quantities of a test rule substance
have generally found it to be in their best interest to develop cost-
sharing arrangements (which typically do not include all persons
subject to providing reimbursement) to cover the costs of testing,
rather than attempting to reach an agreement regarding reimbursement
among the broader group made up of all persons potentially subject to
providing reimbursement, or soliciting the involvement of the Agency
under the reimbursement regulations at 40 CFR part 791 in developing a
reimbursement arrangement. The development of such private cost-sharing
arrangements appears to avoid possible difficulties that could be
associated with coordinating the larger group of all persons
potentially subject to reimbursement under a test rule, and provides
flexibility to the parties to the arrangement because it may take any
form they choose. If the parties are unable to agree upon a cost-
sharing arrangement, they may contact EPA and initiate formal
reimbursement procedures under 40 CFR part 791. These procedures would
include all persons subject to the rule, i.e., all entities from both
Tier 1 and Tier 2.
Other comments related to the issue of reimbursement by Tier 2
entities are listed below:
a. Persons not initially required to comply with a test rule have
never been required to reimburse before (ACC, ACC/O, API). EPA
disagrees. Since 1990, EPA has included processors, small-quantity
manufacturers (i.e., manufacturers of less than 500 kg (1,100 lbs.) of
a test rule chemical), and R&D manufacturers in Tier 2 (See 40 CFR
790.42(a)(2), 40 CFR 790.42(a)(4), and 40 CFR 790.42(a)(5),
respectively). As a result, for the last decade these entities have
been considered subject to test rules, but not initially required to
comply with the requirement that letters of intent to test or exemption
applications be submitted to EPA. Shifting groups of manufacturers and/
or processors to Tier 2 does not ``change the legal rights and
obligations of persons subject to TSCA section 4 test rules, but would
only eliminate some of the paperwork burden associated with
compliance.'' (Ref. 69, p. 18882). In fact, persons included in Tier 2
``would still be subject to test rules (and export notification
requirements as specified in TSCA section 12(b)), and would not be
exempt from reimbursement claims.'' (Ref. 69, p. 18882).
The Agency shifted R&D and small-quantity manufacturers to Tier 2
based on its recognition that, in practice, the administrative costs of
seeking reimbursement from these entities would likely exceed the
reimbursement that might be gained by their participation. Therefore,
the filing of exemption applications by R&D and small-quantity
manufacturers serves no practical purpose (i.e., there is no need for
them to self-identify by submitting exemption applications). As
discussed in the proposed rule, processors were originally put in Tier
2 for another reason, i.e., manufacturers would not likely seek
reimbursement directly from them, but would rather pass their costs on
to processors indirectly via the market. In addition, the large numbers
of processors would create administrative difficulties in making
testing decisions (Ref. 5, p. 31081).
Persons who are subject to a test rule, but who are not initially
required to comply with the test rule have always been potentially
subject to reimbursement under the formal reimbursement procedures at
40 CFR part 791. For example, see the interim final rule amending the
procedural rule at 40 CFR part 790 (Ref. 74, p. 20654), which states
that, where manufacturers and processors are subject to a test rule,
processors will automatically be given a conditional exemption from the
requirement that letters of intent to test or exemption applications be
submitted to EPA. This exemption is conditional because it would be
lifted if none of the persons initially required to comply with the
rule (i.e., manufacturers) submit a letter of intent to test. In
addition, processors may be required to provide reimbursement directly
to those sponsoring the testing.
Although Tier 2 entities are subject to reimbursement under this
final test rule and have been subject under past test rules (see final
rule amending the testing procedural rule at 40 CFR part 790 (Ref. 69),
EPA believes that they have not historically participated in
reimbursement because other manufacturers have always created cost-
[[Page 22422]]
sharing arrangements that did not require their involvement.
b. Tier 1 manufacturers should be those persons who undertake the
activities that, for the most part, give rise to the need for testing.
As a result, they should be the only ones responsible for
reimbursement. EPA should identify upfront in a rule the persons whose
activities warrant their contribution to the cost of testing. All of
these persons should be included in Tier 1, and reimbursement should
only apply to those Tier 1 persons (unless EPA has to resort to
requiring entities in Tier 2 to submit letters of intent to test/
exemption applications, and then Tier 2 would have to reimburse also)
(API). Entities in Tier 1 that obtain an exemption in lieu of testing
should generally be the only persons responsible for reimbursing. EPA
should retain flexibility to impose costs on Tier 2 entities when
circumstances warrant (ACC, ACC/O).
Under TSCA section 4(b)(3)(B), once EPA has made the requisite
regulatory findings with respect to a chemical, ``each person'' who
manufactures (or intends to manufacture) and/or processes (or intends
to process) the chemical ``shall'' be required to conduct tests and
submit data. Tier 2 entities have ``automatic conditional exemptions''
from the requirement that they conduct testing (see Sec.
799.5115(c)(3) of the regulatory text). TSCA sections 4(c)(3) and
4(c)(4) indicate that persons granted exemptions from the requirement
that testing be conducted and data submitted may be required to
reimburse the costs of testing under reimbursement regulations
promulgated by the Agency if the persons subject to the rule do not
otherwise agree on the amount and method of reimbursement. As a result,
although EPA initially exempts Tier 2 entities from requirements
associated with testing and the submission of data, these entities are
not exempt from the requirement that they reimburse the costs of
testing.
EPA does not believe TSCA provides flexibility to impose
reimbursement obligations on Tier 2 entities only when it makes a
determination that the circumstances warrant it, or based on
determinations as to whether particular manufacturers/processors or
specific groups of such entities undertake activities that relate
directly to the rationale for requiring testing. TSCA section 4
indicates that testing responsibilities are not restricted to those who
manufacture or process a test rule chemical in certain forms (such as
restricting the requirements of the rule only to Tier 1 entities).
Rather, persons who manufacture and/or process (depending on the
findings made) a test rule chemical are generally subject to the
requirements of a final test rule. TSCA section 4(b)(3)(B). See also
biphenyl final test rule (Ref. 77, pp. 37184-37185). EPA has created an
exception to this general approach solely for persons who do not know
or who cannot reasonably ascertain that they manufacture and/or process
a test rule chemical.
c. Reimbursement requirements should only apply to persons who may
be required to conduct tests and submit data, i.e., Tier 1 (ACC).
All persons included in either Tier 1 or Tier 2 may be required to
reimburse the costs of testing because all manufacturers and processors
of the chemical substances included in this final test rule are subject
to the final test rule. As the reimbursement regulations (promulgated
pursuant to TSCA section 4(c)(3)(A)) provide: ``[p]ersons subject to a
test rule have an obligation ... either to test or to obtain an
exemption and pay reimbursement'' (40 CFR 791.2(a)). Tier 2 entities
have automatic conditional exemptions from testing requirements, as
discussed earlier. Although Tier 2 entities are not as likely to be
required to conduct testing as Tier 1 entities, both groups are
responsible for reimbursing the person(s) who actually conduct testing.
d. EPA's proposed extension of reimbursement obligations to Tier 2
entities might complicate future efforts to conduct testing under ECAs
(ACC, ACC/O).
EPA is not significantly changing the status quo with regard to
reimbursement obligations established under previous TSCA section 4
regulations. Persons in Tier 2 under previous test rules have been
subject to providing reimbursement. See the final rule amending the
testing procedural rule at 40 CFR part 790 (Ref. 69). The primary
effect of the approach to ``persons required to test'' that was
proposed and is being adopted in this final rule is to better focus the
set of persons included in Tier 1, and to expand and clarify the set of
persons included in Tier 2. EPA is unaware of any reason to believe
that this approach to ``persons required to test'' will make it more
difficult to develop ECAs.
e. EPA has said that manufacturers of impurities, byproducts, and
components of Class 2 substances have not historically participated in
testing or reimbursement. This is true of all other entities included
in Tier 2 under this final rule. Extending reimbursement to Tier 2
disregards this experience (ACC, ACC/O).
EPA agrees that manufacturers of impurities, byproducts, components
of Class 2 substances, and all other entities included in Tier 2 under
this final rule have probably not historically participated in testing
or reimbursement. However, the likely reason they have not participated
is because the costs of testing under test rules promulgated to date
have been contributed to by a smaller group of entities subject to the
rule (the larger manufacturers of each test rule substance), without
the need for EPA's involvement. EPA anticipates that similar cost-
sharing arrangements would continue to occur under this final rule and
other rules using this revised approach to ``persons required to
test,'' as they offer significant advantages to the persons subject to
the rule. If EPA were to become involved in reimbursement via the
reimbursement procedures at 40 CFR part 791, then all Tier 1 and Tier 2
manufacturers and processors would be included in those proceedings.
9. EPA should clarify that the approaches to the ``persons required
to test'' sections in the OSHA dermal and HAPs proposed rules will not
affect the applicability of requirements under TSCA programs outside
those implementing TSCA section 4. ACC/O and ACC commented that where a
particular group (e.g., manufacturers of non-commercial byproducts) is
currently exempt under certain TSCA regulations, it should continue to
be exempt under those regulations regardless of the ``persons required
to test'' approach taken in test rules under TSCA section 4.
The approach the Agency takes in the ``persons required to test''
portion of any given test rule is not intended to affect the status of
persons under regulations other than those relevant to the given test
rule.
J. Economic Impact Analysis
API noted that EPA's Economic Impact Analysis estimates
administrative costs only for companies initially required to comply
with the final test rule (companies in Tier 1). API believes that this
analysis is inappropriate if EPA pursues imposing reimbursement
obligations on Tier 2 entities. If reimbursement obligations are
imposed on Tier 2 companies, API asserts there will be associated
administrative, negotiation, and other costs that EPA should include in
its analysis.
EPA disagrees with this comment. Although Tier 2 entities are
subject to reimbursement, EPA's experience under past test rules has
been that Tier 1
[[Page 22423]]
persons have found it to be in their best interest to develop cost-
sharing arrangements among themselves to cover the cost of testing. The
development of such private cost-sharing arrangements appears to avoid
possible difficulties that could be associated with coordinating a
larger group of persons subject to reimbursement under a test rule, and
provides maximum flexibility to the parties to the arrangement. Because
manufacturers in Tier 1 have been identified for each subject chemical
(see discussion of economic analysis in Unit VIII. (Ref. 57)), EPA
expects that at least one such person will comply with the testing
requirements. EPA is not aware of any circumstances in which Tier 1
entities have sought reimbursement from Tier 2 entities either through
private agreements or by soliciting the involvement of the Agency under
the reimbursement regulations at 40 CFR part 791. Given this consistent
experience with previous TSCA testing actions, EPA does not believe
that there will be any administrative, negotiation, or any other costs
associated with seeking reimbursement from Tier 2 companies.
K. Definition of Small Business
In the preamble of the proposal to this rule (Ref. 5), EPA
requested comment on whether the Agency should establish an alternative
small business definition to use in the small entity impact analyses
for future TSCA section 4(a) test rules, and what size cutoff may be
appropriate.
SOCMA commented that the most appropriate definition to use in
conducting small entity analyses for TSCA section 4(a) test rules is
the employee-based definition established by the U.S. Small Business
Administration (SBA), which for most industries classifies firms as
small based on the number of employees in the firm. The SBA set the
numerical threshold for what is considered small on an industry-by-
industry basis. SOCMA believes that this definition provides EPA with a
straightforward and appropriate distinction between small and large
companies that are closely related to a company's total annual sales.
SOCMA also commented that it does not believe that an alternative
approach, such as the small business definition from TSCA section 8
would be appropriate for conducting impact analyses for TSCA section
4(a) test rules. However, SOCMA believes if EPA were to pursue a sales
volume-based definition of ``small business,'' an appropriate level
would be, at a minimum, a total annual sales of $100 million.
EPA did use SBA's size criteria, which SOCMA stated it prefers, in
its economic analysis for this final rule. Based on the SBA
definitions, EPA has concluded that there are no significant impacts on
small entities (Ref. 57). Regarding SOCMA's second comment, EPA notes
that SOCMA did not provide its reasoning as to why it considers a
definition of small business based on a combination of revenue and
production volume inappropriate, nor did it provide any research or
justification as to why an appropriate level of annual sales used in
such a definition should be set at a minimum of $100 million.
As a more general matter, EPA disagrees with SOCMA's position that
the SBA small business size standards are the most appropriate to use
in analyzing the impacts of TSCA section 4 testing rules. The
Regulatory Flexibility Act (RFA) of 1980, as amended by the Small
Business Regulatory Enforcement Act (SBREFA) of 1996, requires that
special consideration be given to small businesses affected by proposed
Federal regulations. The SBA size standards, which are primarily
intended to determine whether a business entity is eligible for
government programs and preferences reserved for small businesses (13
CFR 121.101), ``seek to ensure that a concern that meets a specific
size standard is not dominant in its field of operation.'' (13 CFR
121.102(b)). See section 632(a)(1) of the Small Business Act. Section
601(3) of RFA establishes as the default definition of ``small
business'' the definition used in section 3 of the Small Business Act,
15 U.S.C. 632, under which the SBA establishes small business size
standards for each industrial sector using an employment threshold that
entities in that sector may not exceed to be classified as small. (13
CFR 121.201). RFA recognizes that it may be appropriate at times to use
an alternate definition of small business for the purpose of analyzing
potential regulatory impacts. As such, section 601(3) of RFA provides
that an agency may establish a different definition of small business
after consultation with the SBA Office of Advocacy and after notice and
an opportunity for public comment.
When assessing the potential impacts of test rules on chemical
manufacturers, EPA believes that a standard based on total annual sales
may provide a more appropriate means to judge the ability of a chemical
manufacturing firm to support chemical testing without incurring
significant costs or burdens. Therefore, EPA is currently determining
what levels of annual sales would provide the most appropriate size
cutoff with regard to various segments of the chemical industry usually
impacted by TSCA section 4(a) test rules. EPA may propose, following
conclusion of its analysis, that an alternative definition based on
sales be established in accordance with section 601(3) of the RFA.
IV. Findings
A. What is the Basis for EPA's Final Rule to Test These Chemical
Substances?
As indicated in Unit II.B., in order to promulgate a rule under
TSCA section 4(a) requiring testing of chemical substances or mixtures,
EPA must make certain findings for those chemical substances or
mixtures regarding either hazard (TSCA section 4(a)(1)(A)(i)); or
exposure (TSCA section 4(a)(1)(B)(i)). EPA is requiring testing of the
chemical substances included in this final rule based on its findings
under TSCA section 4(a)(1)(B)(i) relating to ``substantial production''
and ``substantial human exposure,'' as well as findings under TSCA
sections 4(a)(1)(B)(ii) and (iii). The chemical substances included in
this final rule are listed in Sec. 799.5115(j) of the regulatory text
along with their CAS numbers.
In EPA's policy for making findings under TSCA section
4(a)(1)(B)(i) (i.e., the ``B'' policy), ``substantial production'' of a
chemical substance or mixture is generally interpreted to be aggregate
production (including import) volume equaling or exceeding one million
pounds per year (Ref. 55, p. 28746). The general ``B'' policy threshold
for ``substantial human exposure'' of workers is the exposure of 1,000
workers annually to a chemical substance or mixture (Ref. 55, p.
28746). See EPA's ``B'' policy (Ref. 55) for further discussion on how
EPA generally makes decisions under TSCA section 4(a)(1)(B)(i).
EPA finds that, under TSCA section 4(a)(1)(B)(i), each of the 34
chemical substances included in this final rule is produced in
``substantial quantities'' and there is or may be ``substantial human
exposure'' to each chemical substance (Ref. 56). In addition, under
TSCA section 4(a)(1)(B)(ii), EPA believes that there are insufficient
data and experience to reasonably determine or predict the effects of
the manufacture, processing, or use of these chemical substances, or of
any combination of such activities, on human health or the environment.
In particular, as discussed
[[Page 22424]]
in Unit IV.D., EPA has determined that there are insufficient in vitro
dermal absorption rate data on these chemicals. EPA also finds that
testing of the 34 chemical substances is necessary to develop such data
(TSCA section 4(a)(1)(B)(iii)) (see Unit IV.E.). EPA has not identified
any ``additional factors'' as discussed in the ``B'' policy (Ref. 55,
p. 28746) to cause the Agency to use decision making criteria other
than the general thresholds described in the policy with respect to the
chemicals included in this final rule.
B. Are These Chemical Substances Produced and/or Imported in
Substantial Quantities?
Each of the chemical substances included in this final rule is
produced and/or imported in an amount equal to or greater than one
million pounds per year (Ref. 57), based on information gathered
pursuant to the 2002 TSCA section 8(a) IUR (40 CFR part 710). The IUR
is the most recently available compilation of TSCA Inventory data, and
is contained in the TSCA Chemical Update System. EPA believes that
these annual production volumes are ``substantial'' as that term is
used with reference to production in TSCA section 4(a)(1)(B)(i) (Ref.
55).
C. Are a Substantial Number of Workers Exposed to These Chemicals?
EPA finds that the manufacture, processing, and use of the chemical
substances included in this action result or may result in exposure to
a substantial number of workers. These chemical substances are used in
a wide variety of industrial applications which result in potential
exposures to workers, as described in the exposure support document for
this final rule (Ref. 56).
EPA defines human exposure as the contact with a chemical or agent
at the visible exterior of a person (i.e., skin and openings into the
body such as mouth and nostrils) (Ref. 58, p. 22891). Worker exposure
is the human exposure to a chemical or agent that occurs while a person
is working. Worker exposure may have various causes, with chemical
releases being a common cause of exposure. Chemical manufacturing and
processing plants can release chemicals from pumps as fugitive
emissions, from reactor and condenser vents as stack emissions, in the
form of a vapor and/or as a particulate. Diffusion and air currents may
carry a chemical throughout the plant and workers may breathe air
containing the chemical, resulting in exposures. Certain human
activities such as manually transferring a chemical from one container
to another may also cause exposures.
Each of the chemicals in this final rule was identified in the NOES
as having a total worker exposure of 1,000 workers or more (Ref. 56).
EPA believes that an exposure of 1,000 workers or more to a chemical
substance is or may be ``substantial'' as that term is used with
reference to ``human exposure'' in TSCA section 4(a)(1)(B)(i) (Ref.
55).
D. Do Sufficient Data Exist for These Chemical Substances?
As discussed in this preamble, dermal absorption rate is an
important factor in ascertaining the health effects of the 34 chemicals
in this final rule. EPA has determined that for the 34 chemicals for
which in vitro dermal absorption rate testing is required under this
final rule, there is either no dermal absorption rate information
available or where there is some information, these data are
insufficient to estimate dermal absorption rate. Therefore, existing
data are insufficient to reasonably determine or predict the human
health effects that may result from dermal exposures to the chemical
substances included in this final rule during the manufacturing,
processing, or use of the subject chemical substances. This finding is
based on the review and analysis of relevant data by the ITC (which
included EPA participation), as described in Unit II.A.
E. Is Testing Necessary for These Chemical Substances?
EPA believes that the testing of these 34 subject chemical
substances is necessary to determine if the manufacturing, processing,
or use of these chemical substances may present an unreasonable risk of
injury to human health. In particular, the testing required by this
final rule will provide dermal absorption rate data which OSHA can
consider together with toxicity data to evaluate the need for skin
designations which are used to protect against potential health risks
associated with exposures to these chemicals in the workplace. See Unit
III.B.3. for a detailed description of this and other data needs that
will be filled by the testing required by this final rule.
V. Final Rule
A. What Testing is Required by this Action?
EPA is specifying testing and reporting requirements for the
chemical substances listed in Table 2 in Sec. 799.5115(j) of the
regulatory text according to the in vitro dermal absorption rate test
standard set forth in Sec. 799.5115(h) of the regulatory text.
The test standard that will be used under this final rule was
refined as described in Unit III.B. of the proposed rule (Ref. 5). In
addition, certain modifications which added flexibility to the test
standard have been made in response to comments submitted to EPA and
addressed in Unit III.E.2. of this final rule.
B. When Will the Testing Imposed by this Final Rule Begin?
Once this final rule is effective, which will be 30 days after its
publication in the Federal Register, the required testing must be
initiated at a time sufficient to allow the final report to be
submitted by the deadline indicated in Sec. 799.5115(i) of the
regulatory text, i.e., 13 months after the effective date of the final
rule.
C. How Must the Studies Required Under this Test Rule be Conducted?
Persons required to comply with this final rule must conduct the
necessary testing in accordance with the testing and reporting
requirements described in the regulatory text, and with the TSCA Good
Laboratory Practice Standards (GLPS) (40 CFR part 792). Clarification
was provided in the test standard concerning how data should be
reported. The clarification indicates that means and standard
deviations must be used when reporting the required determinations.
Although the test standard in the proposed rule would have required
three separate determinations for each chemical (i.e., one each for Kp,
10-minute, and 60-minute short-term dermal absorption rates), reporting
each as a mean and standard deviation was not specified. However, good
scientific practice would suggest that the determinations be reported
in this way, and EPA believes that this clarification does not
substantively change the reporting requirements or their burden and
costs (Ref. 57).
D. What Substances Will be Tested Under this Final Rule?
The ``Class 1'' chemical substances listed in Table 2 in Sec.
799.5115(j) of the regulatory text (i.e., 32 of the 34 chemical
substances included in this final rule) must be tested at a purity of
at least 99%. The term Class 1 chemical substance refers to a chemical
substance having a chemical composition that consists of a single
chemical species (not including impurities) that can be represented by
a specific, complete structure diagram. In those instances in which the
test sponsor(s) believes that a 99% level of purity is unattainable for
a given chemical, the sponsor may
[[Page 22425]]
request a modification under the procedures described in 40 CFR 790.55.
For the ``Class 2'' chemical substances listed in Table 2 in Sec.
799.5115(j) of the regulatory text (i.e., 2 of the 34 chemical
substances included in this final rule), EPA is requiring that the
substance to be tested be any representative form of the chemical
substance.
In providing a different approach for identifying the substance to
be tested with regard to Class 2 substances, EPA recognizes two
characteristics which further distinguish Class 2 from Class 1 chemical
substances. First, unlike Class 1 substances, knowledge of the
composition of commercial Class 2 substances can vary in quality and
specificity from substance to substance. The composition of the
chemical species which comprise a Class 2 substance may be:
Well characterized in terms of molecular
formulae, structural diagrams, and compositional percentages of all
species present (for example, methyl phenol);
Less well-characterized, for example,
characterized only by molecular formulae, nonspecific structural
diagrams, and/or by incomplete or unknown compositional percentages of
the species present (for example C12-C14 tert-
alkyl amines); or
Poorly characterized because all that is known
is the identity of only some of the chemical species present and their
percentages of composition, or of only the feedstock and method used to
manufacture the substance (for example, nut shell liquors of cashews).
Second, the composition of some Class 2 substances may vary from
one manufacturer to another, or, for a single manufacturer, from
production run to production run, because of small variations in
feedstock, manufacturing methods, or other production variables. A
``Class 2'' designation most frequently applies to a substance
consisting of a combination of different chemical species that are
either structurally similar or related by being formed together when a
certain chemical reaction or process is carried out on a certain
chemical feedstock. Small variations in the feedstock or in chemical
production methods or conditions can account for the types of small
variations in composition typically allowable within a given Class 2
Inventory listing. By contrast, a ``Class 1'' designation generally
applies to a substance which is an individual chemical whose only
variables are its impurities and byproducts.
EPA believes that, for purposes of this final rule which would
require the determination of a Kp and two in vitro short-term dermal
absorption rates, the testing of any representative form of a subject
Class 2 substance would be relevant to a determination of whether the
chemical substance would or would not present an unreasonable risk to
human health. However, EPA would encourage the selection of
representative forms of the test substances that meet industry or
consensus standards, where they exist. In accordance with TSCA GLPS at
40 CFR part 792, the final study report must include test substance
identification information, including name, CAS No., strength, purity,
and composition, or other appropriate characteristics. (See 40 CFR
792.185).
E. Am I Required to Test Under this Final Rule?
Under TSCA section 4(a)(1)(B), EPA finds that there are
insufficient data and experience to reasonably determine or predict
health effects resulting from the manufacture, processing, or use of
the chemical substances listed in this rulemaking. As a result, under
TSCA section 4(b)(3)(B), manufacturers and processors of these
substances are subject to the final rule with regard to those listed
chemicals which they manufacture or process.
1. Am I subject to this final rule? You are subject to this final
rule and may be required to test if you manufacture (which is defined
by statute to include import) or process, or intend to manufacture or
process, one or more chemical substances listed in Table 2 in Sec.
799.5115(j) of the regulatory text during the time period discussed in
Unit V.E.2. However, if you do not know or cannot reasonably ascertain
that you manufacture or process a listed test substance (based on all
information in your possession or control, as well as all information
that a reasonable person similarly situated might be expected to
possess, control, or know, or could obtain without an unreasonable
burden), you are not subject to the final rule for that listed
substance.
2. When will my manufacture or processing (or my intent to do so)
cause me to be subject to this final rule? You are subject to this
final rule if you manufacture or process, or intend to manufacture or
process, a substance listed in Table 2 in Sec. 799.5115(j) of the
regulatory text at any time from the effective date of the final test
rule to the end of the test cost reimbursement period.
The term reimbursement period is defined at 40 CFR 791.3(h) and may
vary in length for each substance to be tested under a final TSCA
section 4(a) test rule, depending on what testing is required and when
testing is completed. (See Unit V.E.4.).
3. Will I be required to test if I am subject to the final rule? It
depends on the nature of your activities. All persons who are subject
to this TSCA section 4(a) test rule, which, unless otherwise noted in
the regulatory text, incorporates EPA's generic procedures applicable
to TSCA section 4(a) test rules (contained within 40 CFR part 790),
fall into one of two groups, designated here as Tier 1 and Tier 2.
Persons in Tier 1 (those who must initially comply with the final rule)
must either: Submit to EPA letters of intent to conduct testing,
conduct this testing, and submit the test data to EPA or apply to and
obtain from EPA exemptions from testing. Persons in Tier 2 (those who
do not have to initially comply with the final rule) need not take any
action unless they are notified by EPA that they are required to do so,
as described in Unit V.E.3.d. Note that persons in Tier 1 who obtain
exemptions and persons in Tier 2 are nonetheless subject to providing
reimbursement to persons who actually conduct the testing, as described
in Unit V.E.4.
a. Who is in Tier 1 and Tier 2? All persons subject to this final
rule are considered to be in Tier 1 unless they fall within Tier 2. The
following table describes who is in Tier 1 and Tier 2.
[[Page 22426]]
Table 1.--Persons Subject to the Final Rule: Persons in Tier 1 and Tier
2
------------------------------------------------------------------------
Tier 1 (Persons initially required to Tier 2 (Persons not initially
comply) required to comply)
------------------------------------------------------------------------
Persons who manufacture (as defined at Tier 2A
TSCA section 3(7)), or intend to Persons who manufacture (as
manufacture, a test rule substance who defined at TSCA section 3(7))
are not listed under Tier 2 or intend to manufacture a
test rule substance solely as
one or more of the following:
--As a byproduct (as defined at
40 CFR 791.3(c));
--As an impurity (as defined at
40 CFR 790.3);
--As a naturally occurring
substance (as defined at 40
CFR 710.4(b));
--As a non-isolated
intermediate (as defined at 40
CFR 704.3);
--As a component of a Class 2
substance (as described at 40
CFR 720.45(a)(1)(i));
--In amounts of less than 500
kg (1,100 lbs) annually (as
described at 40 CFR
790.42(a)(4)); or
--In small quantities solely
for research and development
(as described at 40 CFR
790.42(a)(5))
Tier 2B
Persons who process (as defined
at TSCA section 3(10)) or
intend to process a test rule
substance (see 40 CFR
790.42(a)(2))
------------------------------------------------------------------------
b. When is it appropriate for a person required to comply with the
rule to apply for an exemption rather than to submit a letter of intent
to conduct testing? You may apply for an exemption if you believe that
the required testing will be performed by another person (or a
consortium of persons formed under TSCA section 4(b)(3)(A)). You can
find procedures relating to exemptions in 40 CFR 790.80 through 790.99,
and Sec. 799.5115(c)(2), (c)(5), (c)(7), and (c)(11) of the regulatory
text. In this final rule, EPA will not require the submission of
equivalence data (i.e., data demonstrating that your substance is
equivalent to the substance actually being tested) as a condition for
approval of your exemption. Therefore, 40 CFR 790.82(e)(1) and 40 CFR
790.85 do not apply to this final test rule.
c. What will happen if I submit an exemption application? EPA
believes that requiring the collection of duplicative data is
unnecessarily burdensome. As a result, if EPA receives a letter of
intent to test from another source or has received (or expects to
receive) the test data that are required under this final rule, the
Agency will conditionally approve your exemption application under 40
CFR 790.87. The Agency will terminate conditional exemptions if a
problem occurs with the initiation, conduct, or completion of the
required testing, or with the submission of the required data to EPA.
EPA may then require you to submit a letter of intent to test or an
exemption application. See 40 CFR 790.93 and Sec. 799.5115(c)(10) of
the regulatory text. Persons who obtain exemptions or receive them
automatically will nonetheless be subject to providing reimbursement to
persons who actually conduct the testing, as described in Unit V.E.4.
d. What are my obligations if I am in Tier 2? If you are in Tier 2,
you are subject to the final rule and you are responsible for providing
reimbursement to persons in Tier 1, as described in Unit V.E.4. You are
considered to have an automatic conditional exemption. You do not need
to submit a letter of intent to test or an exemption application unless
you are notified by EPA that you are required to do so.
If a problem occurs with the initiation, conduct, or completion of
the required testing, or the submission of the required data to EPA,
the Agency may require you to submit a letter of intent to test or an
exemption application. See 40 CFR 790.93 and Sec. 799.5115(c)(10) of
the regulatory text. In addition, you will need to submit a letter of
intent to test or an exemption application if:
No manufacturer in Tier 1 has notified EPA of
its intent to conduct testing.
EPA has published a Federal Register document
directing persons in Tier 2 to submit to EPA letters of intent to
conduct testing or exemption applications. (See Sec. 799.5115(c)(4),
(c)(5), (c)(6), and (c)(7) of the regulatory text.)
The Agency will conditionally approve an exemption application under 40
CFR 790.87, if EPA has received a letter of intent to test or has
received (or expects to receive) the test data required under this
final rule.
e. Subdivision of Tier 2 entities. In the proposed rule that
preceded this final rule, EPA solicited comment on the issue of whether
the Agency should prioritize which persons in Tier 2 would be required
to perform testing, if needed (Ref. 5, p. 31082). Specifically, the
Agency suggested that it could subdivide Tier 2 entities into:
Tier 2A. Tier 2 manufacturers, i.e., those who
manufacture, or intend to manufacture, a test rule substance solely as
one or more of the following: A byproduct; an impurity; a naturally
occurring substance; a non-isolated intermediate; a component of a
Class 2 substance; in amounts less than 1,100 lbs. annually; or in
small quantities solely for research and development.
Tier 2B. Tier 2 processors, i.e., those who
process, or intend to process, a test rule substance (in any form). The
terms ''process'' and ''processor'' are defined by TSCA section 3(10)
and (11), respectively.
After consideration of comments received by the Agency (see Unit
III.I.3.), EPA has decided that it will subdivide Tier 2 in the
suggested manner, and the final rule regulatory text is structured to
reflect this. If the Agency needs testing from persons in Tier 2, EPA
will seek testing from persons in Tier 2A before proceeding to Tier 2B.
It is appropriate to require manufacturers in Tier 2A to submit letters
of intent to test or exemption applications before processors are
called upon because the Agency believes that testing costs are
traditionally passed by manufacturers along to processors, enabling
them to share in the costs of testing (Ref. 74, p. 20654). In addition,
``[t]here are [typically] so many processors [of a given test rule
chemical] that it would be difficult to include them all in the
technical decisions about the tests and in the financial decisions
about how to allocate the costs'' (Ref. 79, p. 31789).
f. How did EPA decide who would be in Tier 1 and Tier 2 and who
would be excluded from the rule? Under 40 CFR 790.2, EPA may establish
procedures applying to specific test rules that differ from the generic
procedures governing TSCA section 4 test rules in 40 CFR part 790. For
the purposes of this final rule, EPA is setting forth certain
requirements
[[Page 22427]]
that differ from those under 40 CFR part 790.
In this test rule, EPA has reconfigured the tiers in 40 CFR 790.42.
EPA has added the following persons to Tier 2: Byproduct manufacturers;
impurity manufacturers; manufacturers of naturally occurring
substances; manufacturers of non-isolated intermediates; and
manufacturers of components of Class 2 substances. The Agency took
administrative burden and complexity into account in determining who
was to be in Tier 1 in this rule. EPA believes that those persons in
Tier 1 who will conduct testing under this final rule will generally be
large chemical manufacturers who, in the experience of the Agency, have
traditionally conducted testing or participated in testing consortia
under previous TSCA section 4(a) test rules.
The Agency also believes that byproduct manufacturers, impurity
manufacturers, manufacturers of naturally occurring substances,
manufacturers of non-isolated intermediates, and manufacturers of
components of Class 2 substances historically have not themselves
participated in testing or contributed to the reimbursement of those
persons who have conducted testing. EPA understands that these
manufacturers may include persons for whom the marginal transaction
costs involved in negotiating and administering testing arrangements
are deemed likely to raise the expense and burden of testing to a level
that is disproportionate to the additional benefits of including these
persons in Tier 1. Therefore, EPA does not believe that the likelihood
of the persons who are being added to Tier 2 actually conducting the
testing is sufficiently high to justify burdening these persons with
Tier 1 requirements (e.g., submitting requests for exemptions).
Nevertheless, these persons, along with all other persons in Tier 2,
are subject to reimbursement obligations to persons who actually
conduct the testing, as described in Unit V.E.4.
TSCA section 4(b)(3)(B) requires all manufacturers and processors
of a chemical substance to test that chemical substance if EPA has made
findings for that chemical substance, and therefore issued a TSCA
section 4(a) test rule requiring testing. However, practicality must be
a factor in determining who is subject to a particular test rule. Thus,
persons who do not know or cannot reasonably ascertain that they are
manufacturing or processing the substances subject to this final rule,
e.g., manufacturers or processors of the substances as trace
contaminants who are not aware of these activities, are not subject to
the final rule. (See Unit V.E.1. and Sec. 799.5115(b)(2) of the
regulatory text.)
4. How do the reimbursement procedures work? In the past, persons
subject to test rules have independently worked out among themselves
their respective financial contributions to those persons who have
actually conducted the testing. However, if persons are unable to agree
privately on reimbursement, they may take advantage of EPA's
reimbursement procedures at 40 CFR part 791, promulgated under the
authority of TSCA section 4(c). These procedures include:
The opportunity for a hearing with the American
Arbitration Association.
Publication by EPA of a Federal Register
document concerning the request for a hearing.
The appointment of a hearing officer to propose
an order for fair and equitable reimbursement.
The hearing officer may base his or her proposed order on the
production volume formula set out at 40 CFR 791.48, but is not
obligated to do so. Under this final rule, amounts manufactured as
impurities will be included in production volume (40 CFR 791.48(b)),
subject to the discretion of the hearing officer (40 CFR 791.40(a)).
The hearing officer's proposed order may become the Agency's final
order, which is reviewable in Federal court (40 CFR 791.60).
F. What are the Reporting Requirements Under this Final Rule?
A final report must be submitted for each chemical 13 months after
the effective date of the final rule, i.e., by the deadline indicated
in Sec. 799.5115(i) of the regulatory text. Although EPA originally
proposed a deadline of 9 months after the effective date, EPA extended
the reporting deadline to 13 months after the effective date in
response to public comments. (See Unit III.E.2.f.). EPA is not
requiring the submission of interim progress reports for the in vitro
dermal absorption rate testing required in this final rule. For the
short-term studies required by this final rule, interim progress
reports would likely yield little useful information. Furthermore, by
not requiring interim progress reports for these short-term studies,
the overall burden of the final rule will be somewhat reduced.
G. What Would I Need to Do if I Cannot Complete the Testing?
A company that submits a letter of intent to test under this final
rule and that subsequently anticipates difficulties in completing the
testing by the deadline may submit a request to the Agency to modify
the test schedule, pursuant to 40 CFR 790.55. EPA will determine
whether modification of the test schedule is appropriate, and may first
seek public comment on the modification.
H. Will There be Sufficient Test Facilities and Personnel to Undertake
the Testing in this Test Rule?
Various surveys of the availability of test facilities and
personnel to handle the additional demand for testing services created
by TSCA section 4(a) test rules indicate that available test facilities
and personnel will adequately accommodate the testing specified in this
final rule (Refs. 46, 52, and 53) (see also Unit III.G.).
I. Might EPA Seek Further Testing of the Chemicals in this Final Rule?
If EPA determines that it needs additional data regarding any of
the chemical substances included in this final rule, the Agency might
seek further health and/or environmental effects testing for these
chemical substances. Should the Agency decide to seek such additional
testing, EPA would initiate a separate action under TSCA section 4 for
that purpose.
VI. Export Notification
Any person who exports, or who intends to export, one of the
chemical substances contained in this final rule in any form is subject
to the export notification requirements in TSCA section 12(b)(1) and at
40 CFR part 707, subpart D. However, export notification is generally
not required for articles, as provided by 40 CFR 707.60(b).
VII. Decision to Terminate Rulemaking
EPA is withdrawing the in vitro dermal absorption rate testing
proposed on June 9, 1999 (64 FR 31074) for 13 chemicals: Ethyl ether,
isobutyl alcohol, sec-butyl alcohol, o-dichlorobenzene, p-nitrotoluene,
beta-chloroprene, n-amyl acetate, N-isopropylaniline, o-dinitrobenzene,
ethyl bromide, o-chlorotoluene, disulfiram, and N,N-dimethylaniline.
The rationale for the decision to withdraw this proposed testing is
presented in this unit.
A. Ethyl Ether
DEPA commented that ethyl ether (CAS No. 60-29-7) should be removed
from the rule, in part, because dermal
[[Page 22428]]
absorption rate data had previously been developed and because the high
volatility of ethyl ether would not allow a dermal absorption rate to
be adequately determined under the proposed standard (Ref. 21).
EPA and OSHA have reviewed the dermal absorption rate study by
Blank et al., 1967 (Journal of Investigative Dermatology. 49:582-589),
submitted by DEPA as an attachment to its comments (Ref. 21). The study
measured a Kp for an aqueous solution of ethyl ether through a human
abdominal epidermal membrane using an in vitro static diffusion cell.
Barrier function was maintained as verified by measuring penetration of
tritiated water. Most other experimental parameters conformed with the
standard proposed by EPA for determining an in vitro dermal absorption
rate. A sensitive gas chromatographic method was used to analyze the
receptor fluid in place of radiolabeled compound. It is unclear whether
absorption was determined under occluded or unoccluded conditions, but
the Kp values are close to theoretical calculations, indicating that
ethyl ether evaporation likely did not confound absorption measurements
under these experimental conditions. Skin penetration of the neat
liquid was not reported, but EPA and OSHA believe this can be estimated
using the aqueous Kp value and data on water solubility and liquid
density. Therefore, EPA and OSHA believe that this study provides
sufficient data for an adequate determination of the dermal absorption
rate information sought in this rulemaking and testing of ethyl ether
is not required at this time (Ref. 62).
B. Isobutyl Alcohol and Sec-Butyl Alcohol
ACC, in its comment proposing a category approach when testing
chemical substances to determine in vitro dermal absorption rates,
noted that in its suggested aliphatic alcohol category, three of the
four possible isomers for butyl alcohol were included in the proposed
rule (Ref. 15). ACC stated that given their same molecular weight and
functionality, and taking into consideration the likelihood of there
being existing dermal absorption rate data for other three-, four-, and
five-carbon alcohols, evaluating the three isomers using a structure
activity relationship (SAR) approach would appear reasonable, in lieu
of testing three chemicals under this rule.
The three butyl alcohols referred to by ACC are isobutyl alcohol
(CAS No. 78-83-1), sec-butyl alcohol (CAS No. 78-92-2), and tert-butyl
alcohol (CAS No. 75-65-0). The first two were included in the proposed
rule. The third substance, tert-butyl alcohol was cited in the proposed
rule (Ref. 5) as a chemical substance that was removed from the test
list as a result of a 1998 study. The fourth butyl alcohol, not
included in the proposed test rule, is n-butyl alcohol (CAS No. 71-36-
3) which the ITC found to have sufficient dermal absorption rate data.
EPA agrees with ACC that sufficient data on in vitro dermal
absorption rates have been generated on three, four, and five carbon
aliphatic alcohols to adequately predict Kps for isobutyl alcohol and
sec-butyl alcohol (Ref. 62). In vitro dermal absorption rates and Kps
using human skin have already been measured for a series of homologous
two [ethanol], three [propanol], four [n-butanol], and five [pentanol]
carbon aliphatic alcohols (Ref. 65). This provides adequate structure
activity information to predict the dermal absorption rates for the
closely related branched chain alcohols, isobutyl alcohol and sec-butyl
alcohol, with reasonable accuracy. Therefore, EPA is not requiring the
testing of isobutyl alcohol and sec-butyl alcohol under this final
rule.
C. o-Dichlorobenzene
The Chlorobenzene Producers Association cited two documents to
support its position that testing of o-dichlorobenzene (CAS No. 95-50-
1) is unnecessary (Ref. 31). The Association cited EPA's Dermal
Exposure Assessment: Principles and Applications (Ref. 42), which
described a calculated Kp for o-dichlorobenzene. The Association also
noted that a study conducted at the North Carolina State University at
Raleigh entitled Percutaneous Absorption of Volatile Compounds (Ref.
50) analyzed the relative absorption and penetration of o-
dichlorobenzene on the skin surface in the context of evaluating
volatile organic compounds.
The Kp value for o-dichlorobenzene cited in the 1992 EPA Report on
dermal exposure assessment is estimated from empirical models rather
than experimental data and, therefore, does not meet OSHA needs.
However, the data developed for o-dichlorobenzene in the context of
evaluating percutaneous absorption of volatile organic compounds does
provide a measure of the dermal absorption rate of o-dichlorobenzene.
Therefore, testing of o-dichlorobenzene is not required in this final
rule.
D. p-Nitrotoluene
First Chemical Corporation provided EPA with biological monitoring
information (Ref. 17a.), toxicity studies (Ref. 17b.), and specific
information on the numbers of workers exposed to p-nitrotoluene (CAS
No. 99-99-0) (Ref. 17). First Chemical Corporation concluded from the
submitted information that p-nitrotoluene does not present a
significant hazard from dermal contact and proposed that this chemical
be removed from the test list. One study (Ref. 17a.) discussed
biological monitoring in workers but did not measure dermal absorption.
An acute toxicity study with short-term dermal administration to
experimental animals was negative (Ref. 17b.). This study also did not
attempt to measure dermal absorption, and, therefore is not adequate to
eliminate the testing requirement. A submission under section 8(d) of
TSCA ``found no evidence of skin absorption when a dermal dose of 1.0
g/kg was applied to rabbits'' (Ref. 17) but further review by EPA finds
no mention of the methodology or data that support this statement in
the submission. EPA does not consider the data cited by First Chemical
Corporation to be sufficient to determine a dermal absorption rate for
p-nitrotoluene (Ref. 62).
First Chemical Corporation also submitted data relevant to EPA's
finding of substantial human exposure. First Chemical Corporation is
the only domestic manufacturer of p-nitrotoluene and accounts for the
vast majority of the total quantity on the U.S. market. The company
provided information on handling procedures, onsite operations, and a
summary of the number of workers with potential exposure to the
chemical. This summary was based on a survey of onsite operations and
inquiries to each offsite company known to handle p-nitrotoluene. EPA
has reviewed these data and agrees with First Chemical Corporation that
the number of workers exposed to p-nitrotoluene at its facilities and
those of its customers (processors) do not meet the general worker
threshold for substantial human exposure that EPA has established to
require testing under TSCA section 4(a)(1)(B). EPA has also reviewed
the information submitted in response to the TSCA section 8(a) PAIR for
p-nitrotoluene (Ref. 8). PAIR information for 1994 revealed that
another company in the p-nitrotoluene market did not use p-nitrotoluene
in its processes, sell it to its customers, or report any worker
exposure, thus making the number of exposed workers reported by First
Chemical Corp. the total of the reported worker exposures in the United
States. Therefore, EPA is
[[Page 22429]]
not requiring testing of p-nitrotoluene under this final rule.
E. beta-Chloroprene
DuPont Dow Elastomers (DDE) provided EPA with specific information
on production and worker exposure to beta-chloroprene (CAS No. 126-99-
8) during production and use (Ref. 24). According to DDE, domestic
production of beta-chloroprene occurs only at DDE's facility in
LaPlace, Louisiana. DDE also states that no beta-chloroprene is
imported. DDE acknowledges that beta-chloroprene is manufactured in
quantities in excess of one million pounds per year which satisfies the
``substantial production'' TSCA section 4(a)(1)(B) finding. However,
the company maintains that the number of workers exposed to beta-
chloroprene does not meet the general ``substantial human exposure''
TSCA section 4(a)(1)(B) finding.
According to DDE, more than 90% of beta-chloroprene produced
annually is used for the production of dry polychloroprene. Most of the
remaining beta-choloroprene is used to produce polychloroprene latex, a
colloidal suspension of polychloroprene in water. A small portion is
used to manufacture a comonomer, subsequently incorporated in
polychloroprene polymerization. DDE states that polymer manufacture is
the only commercial use of beta-chloroprene. From its sole beta-
chloroprene production facility in Louisiana, DDE produces beta-
chloroprene monomer to supply its polychloroprene manufacturing
operations. DDE, the only domestic producer of beta-chloroprene or
polychloroprene, handles beta-chloroprene at only two of its facilities
and the total number of DDE employees at these sites is approximately
500. DDE states that the actual number of the workers exposed via the
dermal route is significantly less than the total number of DDE
employees at the two facilities that manufacture or handle beta-
chloroprene. DDE has determined that the total number of workers
potentially exposed to beta-chloroprene vapor is less than 200. Due to
the nature of the beta-chloroprene and polychloroprene manufacturing
processes, the number of workers with potential exposure to liquid
beta-chloroprene is apparently significantly less than those
potentially exposed to beta-chloroprene vapor.
EPA has reviewed the production and worker exposure information
submitted by DDE and concurs with DDE in its assessment of the
potential number of workers exposed to beta-chloroprene. Because the
potential number of workers exposed to beta-chloroprene does not appear
to meet the threshold that EPA generally relies upon in making the TSCA
section 4(a)(1)(B) ``substantial human exposure'' finding on the basis
of worker exposure, testing of beta-chloroprene is not required under
this final rule.
F. n-Amyl acetate
EPA and OSHA have reviewed a dermal absorption study for n-amyl
acetate (CAS No. 628-63-7) submitted by Union Carbide Corporation (Ref.
47). A Kp and 6-24 hours dermal absorption rates for n-amyl acetate
were determined. Absorption data were also collected at earlier time
points of 10 minutes and 1 hour. The method used an in vitro static
diffusion cell technique with human cadaver skin and was similar, but
not identical, to the test standard for the study required in this
final rule. The test substance was a mixed isomer of primary amyl
acetate applied neat (65% n-amyl acetate) rather than as a pure
compound. A sensitive (non-radiolabeled) gas chromatographic technique
specific to n-amyl acetate was used as a detection method. The
anatomical region of the skin and membrane thickness were not stated,
although variability in the results and the method of epidermal
membrane preparation were found to be acceptable. The receptor fluid
was ethanol in water instead of the PEG solution required in the test
standard for this final rule; however, it is unlikely that this
influenced the results of the study because ethanol in water, as stated
previously in Unit III.E.2.o.vii., is generally a suitable receptor
fluid. This is the case despite the fact that under this final rule EPA
is requiring the use of a PEG solution as the receptor fluid for all
hydrophobic chemicals for purposes of consistency. Therefore, EPA and
OSHA believe that this study provides sufficient data for an adequate
determination of dermal absorption rate and further testing of n-amyl
acetate is not required under this final rule (Ref. 64).
G. N-Isopropylaniline
Monsanto Company provided EPA with specific information on
production and worker exposure to N-isopropylaniline (CAS No. 768-52-5)
during production and use (Ref. 16). Monsanto Company stated that N-
isopropylaniline is an intermediate in the production of the pesticide
propachlor, the active ingredient in Ramrod branded herbicides, and is
produced and consumed at the Monsanto plant in Muscatine, Iowa. No N-
isopropylaniline is sold or used domestically for any other purpose.
Propachlor, which was introduced on the market in 1965, is nearing the
end of its commercial life cycle and production of N-isopropylaniline
has fallen accordingly. Thus, it is anticipated that N-isopropylaniline
will be produced in amounts far less than the Agency's general
``substantial production'' threshold of one million pounds per year.
Monsanto Company also provided EPA with a detailed description of
the number of workers exposed to N-isopropylaniline during production
and use. N-isopropylaniline is produced and consumed in enclosed
systems. Monsanto Company projected a maximum of 35 workers are
potentially exposed to N-isopropylaniline.
EPA has reviewed the production and worker exposure information
submitted by Monsanto Company for N-isopropylaniline. EPA has
confirmed, via 1998 and 2002 IUR data (see 40 CFR part 710), that
manufacture (including import) of N-isopropylaniline is below the one
million pounds per year threshold which EPA generally relies upon as
``substantial production'' under TSCA section 4(a)(1)(B). In addition,
the potential number of workers exposed to N-isopropylaniline does not
appear to meet the ``substantial human exposure'' threshold of exposure
equal to or greater than 1,000 workers which EPA generally relies upon
in making the TSCA section 4(a)(1)(B) ``substantial human exposure''
finding on the basis of worker exposure. As a result, testing of N-
isopropylaniline is not required under this final rule.
H. o-Dinitrobenzene
EPA received no comments in response to its proposal to require
that o-dinitrobenzene (CAS No. 528-29-0) be tested to determine an in
vitro dermal absorption rate. In developing a finding for the final
rule of ``substantial production'' under TSCA section 4(a)(1)(B) for
this chemical, EPA found that according to 1998 IUR data (see 40 CFR
part 710), o-dinitrobenzene is no longer produced or imported in
amounts equal to or greater than one million pounds per year. The 1998
IUR data became available after the publication of the proposed rule,
which made a finding for substantial production based on 1994 IUR data.
Also, there were no 2002 IUR data reported for o-dinitrobenzene.
Because the 1998 IUR data and the lack of 2002 IUR data do not support
a finding of substantial production as required under TSCA section
4(a)(1)(B)(i), testing of o-dinitrobenzene to determine an in vitro
absorption rate is not required at this time.
[[Page 22430]]
I. Ethyl Bromide, o-Chlorotoluene, Disulfiram, and N,N-Dimethylaniline
In developing findings for the final rule of ``substantial
production'' under TSCA section 4(a)(1)(B) for ethyl bromide (CAS. No.
74-96-4), o-chlorotoluene (CAS No. 95-49-8), disulfiram (CAS No. 97-77-
8), and N,N-dimethylaniline (CAS No. 121-69-7), EPA found that
according to 2002 IUR data (see 40 CFR part 710), these four chemical
substances are no longer manufactured or imported in amounts equal to
or greater than one million pounds per year. Because the 2002 IUR data
show manufacture (including import) below the one million pounds per
year threshold which EPA generally relies upon as ``substantial
production'' under TSCA section 4(a)(1)(B)(i), testing of ethyl
bromide, o-chlorotoluene, disulfiram, and N,N-dimethylaniline to
determine in vitro dermal absorption rates is not required at this
time.
VIII. Economic Impacts
EPA has prepared an economic assessment entitled Economic Impact
Analysis and Small Entity Impact Analysis of the TSCA Section 4(a) Test
Rule for 34 Chemicals Targeted for In Vitro Dermal Absorption Rate
Testing (Ref. 57), a copy of which has been placed in the official
public docket. This economic assessment evaluates the potential for
significant economic impacts as a result of the testing that would be
required by this final rule. The total cost of providing test data on
the 34 chemicals that were evaluated in this economic analysis is
estimated to be a total of $1.16 million for all 34 chemicals, or
$33,987 per chemical (Ref. 57).
While legally subject to this test rule, Tier 2 manufacturers and
all processors of a subject chemical would only be required to comply
with the requirements of the final rule if they are directed to do so
by EPA as described in Sec. 799.5115(c)(5), (c)(7) and (c)(10) of the
regulatory text. EPA would require Tier 2 manufacturers or processors
to test only if no Tier 1 manufacturer has submitted a letter of its
intent to conduct testing, or if, under 40 CFR 790.93, a problem occurs
with the initiation, conduct, or completion of the required testing, or
the submission of the required data to EPA. Because EPA has identified
at least one manufacturer in Tier 1 for each subject chemical, the
Agency expects that, for each chemical in this final rule, at least one
such person will submit a letter of intent to conduct the required
testing and that person will conduct such testing and will submit the
test data to EPA. EPA believes, therefore, that there will not be any
costs to Tier 2 manufacturers or processors for conducting the testing
required by the final rule. In addition, as explained in Unit III.J.,
EPA is not aware of any circumstances in which Tier 1 entities have
sought reimbursement from Tier 2 entities either through private
agreements or by soliciting the involvement of the Agency under the
reimbursement regulations at 40 CFR part 791. Given this consistent
experience with previous test rules, EPA does not believe that there
will be any administrative, negotiation, or any other costs associated
with seeking reimbursement from Tier 2 companies.
To evaluate the potential for an adverse economic impact of testing
on manufacturers of the chemical substances in this final rule, EPA
employed a screening approach that compares the annual revenues from
the sale of a chemical to the annualized testing costs for that
chemical and expresses the testing costs as a percent of revenues
generated from each chemical. Annualized testing costs divide testing
expenditures into an equivalent, constant yearly expenditure over a
longer period of time. To calculate the percent price impact, testing
costs (including laboratory and administrative expenditures) are
annualized over 15 years using a 7% discount rate. Annualized testing
costs are then divided by the estimated annual revenue of the chemical
to derive the cost-to-sales ratio.
EPA estimates the annualized cost of testing the 34 chemicals
evaluated in the economic analysis to be $3,732 per chemical or a total
annualized cost of $126,888 for all 34 chemicals (34 x $3,732) (Ref.
57). In addition, the TSCA section 12(b) export notification that is
required for the first export to a particular country of a chemical
subject to the final rule, is estimated to be $61.31 for the first time
that an exporter must comply with TSCA section 12(b) export
notification requirements, and $18.07 for each subsequent export
notification submitted by an exporter (Ref. 57). The Agency's estimated
total costs of testing (including both laboratory and administrative
costs), annualized testing costs, price impacts, and public reporting
burden hours for this final rule are presented in the economic impact
analysis (Ref. 57).
Price data were available for 26 of the 34 chemicals, with an
average cost of $.88 per pound for those 26 chemicals. The price impact
of the test costs is a function of the chemical's price per pound and
the production volume. For 21 of the 26 chemicals (80.8%) for which
price data were available, the price impact is less than 1.0% when the
production volume for each chemical is assumed to be one million
pounds, which is the threshold for substantial production. The average
test cost impact for all 26 chemicals with price data was 0.68%. This
means that the testing costs represent, on average, 0.68% of revenues
generated from each chemical. The actual impacts are likely to be
lower, however, because all of the subject chemicals are produced in
volumes of at least one million pounds per year. With a price impact of
less than 1.0%, EPA concludes that for these 21 chemicals the potential
for adverse economic impacts is low.
For five of the twenty-six chemicals (19.2%) with price data, the
price impact is in excess of 1.0%. The average price impact for these
five chemicals is 1.96% and the maximum is 3.7%. Again, these impacts
occur when the production volumes are assumed to be one million pounds.
The actual impacts decline in direct proportion to a chemical's actual
production volume above one million pounds. Thus, if the actual
production volume is two million pounds, the impact is reduced by 50%.
The Agency verified production volumes for these five chemicals based
on the 2002 reports to the TSCA Chemical Update System Database, and
has found that the actual production volume in each case exceeds 10
million pounds per year. Therefore, the Agency believes that the impact
for all five of these chemicals is below 1.0%.
The Agency computed ``critical prices'' for the remaining eight
chemicals for which price data were not available. The ``critical
price'' is the price per pound below which there would be an impact of
1.0% or greater. Assuming a minimum production volume of one million
pounds per year and annualized testing costs of $3,732 per chemical,
the critical price is $0.37 per pound. Below that price, the testing
costs would represent more than 1.0% of the revenues from the chemical
at a one million pound production volume level. The average price for
the 26 chemicals with actual price data available is $0.88 per pound.
Thus, the critical price is substantially below this average. While it
cannot be shown conclusively that the price impacts will be less than
or greater than 1.0% of the sales for these chemicals, the Agency
believes that adverse impacts are unlikely, given that both the
chemicals' prices would have to be below $.37 per pound, and the
production volume would have to meet the worst-case assumption of one
million pounds per year.
[[Page 22431]]
On the basis of these calculations, EPA believes that the required
chemical testing presents a low potential for adverse economic impact
for the majority of the chemicals subject to the final rule. Because
the subject chemical substances have relatively large production
volumes, the annualized costs of testing, expressed as a percentage of
annual revenues, are very small for most chemicals. There are, however,
eight chemicals for which it cannot conclusively be shown that the
price impact will be below 1.0% of the revenue for these chemicals. For
these eight chemicals, companies may choose to use revenue sources
other than profits from the individual chemicals to pay for testing. To
account for this, the Agency also compared the costs of compliance to
company sales data. These calculations were made as part of the
Agency's small entity impact analysis (Ref. 57), conducted in
accordance with the requirements of the Regulatory Flexibility Act, as
amended by the Small Business Regulatory Enforcement Fairness Act.
These results are presented in Unit X.B.
IX. Materials in the Docket
An official docket was established under docket ID number OPPT-
2003-0006. The official public docket includes information considered
by EPA in developing this final rule, such as the documents
specifically referenced in this action, any public comments received,
and other information related to this action. In addition, interested
parties should consult documents that are referenced in the documents
that EPA has placed in the docket, regardless of whether these
referenced documents are physically located in the docket. For
assistance in locating documents that are referenced in documents that
EPA has placed in the docket, but that are not physically located in
the docket, please consult one of the technical persons listed under
FOR FURTHER INFORMATION CONTACT. The official public docket is
available for review as specified in ADDRESSES. The following is a
listing of the documents referenced in this preamble that have been
placed in the official docket for this final rule:
A. Supporting Documentation
1. U.S. Census Bureau. Bridge between NAICS and SIC. 1997 Economic
Census. Core Business Statistics Series. Issued June 2000.
2. United States Environmental Protection Agency (USEPA).
Laboratory Cost Estimate for In Vitro Dermal Absorption Rate Testing--
Short-term Absorption Rate. Prepared by Economic and Policy Analysis
Branch (EPAB), Economics, Exposure and Technology Division (EETD),
OPPT. February 20, 2003.
3. USEPA. Laboratory Cost Estimate for In Vitro Dermal Absorption
Rate Testing--Long-term Absorption Rate. Prepared by EPAB, EETD, OPPT.
March 26, 2003.
4. Background information listed in Sec. 799.5115(h)(8) of the
regulatory text:
a. Bronaugh, R.L., Stewart, R.F., and Simon, M. Methods for in
vitro Percutaneous Absorption Studies VII: Use of Excised Human Skin.
Journal of Pharmaceutical Sciences. 75:1094-1097. 1986.
b. Bronaugh, R.L. and Stewart, R.F. Methods for in vitro
Percutaneous Absorption Studies IV: The Flow-Through Diffusion Cell.
Journal of Pharmaceutical Sciences. 74:64-67. 1985.
c. Bronaugh, R.L., Stewart, R.F., and Storm, J.E. Extent of
Cutaneous Metabolism During Percutaneous Absorption of Xenobiotics.
Toxicology and Applied Pharmacology. 99:534-543. 1989.
d. Walker, J.D., Whittaker, C. and McDougal, J.N. Role of the TSCA
Interagency Testing Committee in Meeting the U.S. Government Data
Needs: Designating Chemicals for Percutaneous Absorption Rate Testing.
Dermatotoxicology. F. Marzulli and H. Maibach, Eds. Taylor & Francis,
Washington, DC. pp. 371-381. 1996.
e. Bronaugh, R.L., and Collier, S.W. Protocol for In Vitro
Percutaneous Absorption Studies. In Vitro Percutaneous Absorption:
Principles, Fundamentals, and Applications. R.L. Bronaugh and H.I.
Maibach, Eds. CRC Press, Boca Raton, FL. pp. 237-241. 1991.
B. References
1. Interagency Testing Committee (ITC). Thirty-First Report of the
TSCA Interagency Testing Committee to the Administrator; Receipt of
Report, Request for Comments, Opportunity to Initiate Negotiations for
TSCA Section 4 Testing Consent Agreements. Federal Register (58 FR
26898, May 5, 1993) (FRL-4583-4).
2. ITC. Thirty-Second Report of the TSCA Interagency Testing
Committee to the Administrator; Receipt of Report, Request for
Comments, Notice of Opportunity to Initiate Negotiations for TSCA
section 4 Testing Consent Agreements. Federal Register (58 FR 38490,
July 16, 1993) (FRL-4630-2).
3. ITC. Thirty-Fourth Report of the TSCA Interagency Testing
Committee to the Administrator; Receipt of Report and Request for
Comments. Federal Register (59 FR 35720, July 13, 1994) (FRL-4870-4).
4. ITC. Thirty-Fifth Report of the TSCA Interagency Testing
Committee to the Administrator; Receipt of Report, Request for
Comments, Solicitation of Interested Parties in Developing Testing
Consent Agreement. Federal Register (59 FR 67596, December 29, 1994)
(FRL-4923-2).
5. USEPA. Proposed Test Rule for In Vitro Dermal Absorption Rate
Testing of Certain Chemicals of Interest to Occupational Safety and
Health Administration. Federal Register (64 FR 31074, June 9, 1999)
(FRL-5760-3).
6. USEPA. Preliminary Assessment Information and Health and Safety
Data Reporting; Addition of Chemicals. (TSCA Sections 8(a) and 8(d)
Final Rules for Chemicals contained in the ITC's 31\st\ Report to the
EPA Administrator). Federal Register (58 FR 68311, December 27, 1993)
(FRL-4644-1).
7. USEPA. Preliminary Assessment Information and Health and Safety
Data Reporting; Addition of Chemicals. (TSCA sections 8(a) and 8(d)
Final Rules for Chemicals contained in the ITC's 32\nd\ Report to the
EPA Administrator). Federal Register (59 FR 5956, February 9, 1994)
(FRL-4745-5).
8. USEPA. Preliminary Assessment Information and Health and Safety
Data Reporting; Addition of Chemicals. (TSCA Sections 8(a) and 8(d)
Final Rules for Chemicals contained in the ITC's 35\th\ Report to the
EPA Administrator). Federal Register (60 FR 34879, July 5, 1995) (FRL-
4954-9).
9. USEPA. Thirty-Sixth Report of the TSCA Interagency Testing
Committee to the Administrator; Receipt of Report, Request for
Comments, Solicitation of Use and Exposure Data. Federal Register (60
FR 42982, August 17, 1995) (FRL-4965-6).
10. USEPA. Request for Proposals for Enforceable Consent
Agreements; Dermal Absorption Rate Testing of Eighty OSHA Chemicals;
Solicitation of Interested Parties; Text of Test Protocol. Federal
Register (61 FR 14773, April 3, 1996) (FRL-5359-3).
11. ARCO Chemical Company. Proposal to conduct in vivo dermal
absorption rate testing for tert-butyl alcohol under an enforceable
consent agreement (ECA). Letter from Joan McCuen to Charles M. Auer,
OPPT, USEPA. June 26, 1996.
12. ARCO Chemical Company. A letter from Joan McCuen to Keith
Cronin, OPPT, USEPA transmitting a dermal absorption rate study (Ref.
12a.). March 23, 1998.
12a. Huntington Life Sciences Ltd., Suffolk, England. [14C]-t-Butyl
Alcohol:
[[Page 22432]]
Topical Application: Dermal Absorption Study in the Male Rat; Final
Report. Prepared for ARCO Chemical Company. January 7, 1998.
13. Bronaugh, R.L. and Collier, S.W. Protocol for in vitro
Percutaneous Absorption Studies. In Vitro Percutaneous Absorption:
Principles, Fundamentals, and Applications. R.L. Bronaugh and H.I.
Maibach, Eds. CRC Press, Boca Raton, FL. Chapter 19, pp. 237-241. 1991.
14. Chemical Manufacturers Association (CMA). Comments on ITC
proposal for dermal penetration testing and protocol (Ref. 14a.)
proposed by CMA. Letter from Sarah Doelp to Charles M. Auer, USEPA.
October 21, 1994.
14a. CMA, Existing Chemicals Testing Task Group. Proposed Protocol
for In Vitro Percutaneous Absorption Studies. October 4, 1994.
15. ACC. Comments on EPA's TSCA section 4(a)(1)(B) Proposed Test
Rule for In Vitro Dermal Absorption Rate Testing of Certain Chemicals
of Interest to OSHA submitted to the TSCA Public Docket Office, USEPA.
August 10, 1999.
16. Monsanto Company. Comments on EPA's TSCA section 4(a)(1)(B)
Proposed Test Rule for In Vitro Dermal Absorption Rate Testing of
Certain Chemicals of Interest to OSHA submitted to the TSCA Public
Docket Office, USEPA. July 19, 1999.
17. First Chemical Company. Comments on EPA's TSCA section
4(a)(1)(B) Proposed Test Rule for In Vitro Dermal Absorption Rate
Testing of Certain Chemicals of Interest to OSHA submitted to the TSCA
Public Docket Office, USEPA. August 4, 1999.
17a. Linch, A.L. Biological monitoring for industrial exposure to
cyanogenic aromatic nitro and amino compounds. American Industrial
Hygiene Association Journal. 35:426-432. 1974.
17b. Kinkead, E.R., MacEwen, J.D., Haun, C.C., Vernot, E.H., and
Dacre, J.C. Toxic hazards evaluation of five atmospheric pollutants
from Army ammunition plants. Prepared by University of California,
Irvine for Aerospace Medical Research Laboratory, Wright-Patterson Air
Force Base, OH. Report number AMRL-TR-77-25. June 1977.
18. American Forest & Paper Association. Comments on EPA's TSCA
section 4(a)(1)(B) Proposed Test Rule for In Vitro Dermal Absorption
Rate Testing of Certain Chemicals of Interest to OSHA submitted to the
TSCA Public Docket Office, USEPA. August 9, 1999.
19. American Petroleum Institute. Comments on EPA's TSCA section
4(a)(1)(B) Proposed Test Rule for In Vitro Dermal Absorption Rate
Testing of Certain Chemicals of Interest to OSHA submitted to the TSCA
Public Docket Office, USEPA. August 9, 1999.
20. Biphenyl Work Group, Washington, DC. Comments on EPA's TSCA
section 4(a)(1)(B) Proposed Test Rule for In Vitro Dermal Absorption
Rate Testing of Certain Chemicals of Interest to OSHA submitted to the
TSCA Public Docket Office, USEPA. August 6, 1999.
21. Diethyl Ether Producers Association, Inc. Comments on EPA's
TSCA section 4(a)(1)(B) Proposed Test Rule for In Vitro Dermal
Absorption Rate Testing of Certain Chemicals of Interest to OSHA
submitted to the TSCA Public Docket Office, USEPA. August 9, 1999.
22. Synthetic Organic Chemical Manufacturers Association, Inc.
Comments on EPA's TSCA section 4(a)(1)(B) Proposed Test Rule for In
Vitro Dermal Absorption Rate Testing of Certain Chemicals of Interest
to OSHA submitted to the TSCA Public Docket Office, USEPA. August 9,
1999.
23. Acetonitrile Task Force. Comments on EPA's TSCA section
4(a)(1)(B) Proposed Test Rule for In Vitro Dermal Absorption Rate
Testing of Certain Chemicals of Interest to OSHA submitted to the TSCA
Public Docket Office, USEPA. August 9, 1999.
24. DuPont Dow Elastomers. Comments on EPA's TSCA section
4(a)(1)(B) Proposed Test Rule for In Vitro Dermal Absorption Rate
Testing of Certain Chemicals of Interest to OSHA submitted to the TSCA
Public Docket Office, USEPA. August 9, 1999.
25. Fragranced Products Information Network. Comments on EPA's TSCA
section 4(a)(1)(B) Proposed Test Rule for In Vitro Dermal Absorption
Rate Testing of Certain Chemicals of Interest to OSHA submitted to the
TSCA Public Docket Office, USEPA. July 6, 1999.
26. Association of Veterinarians for Animal Rights. Comments on
EPA's TSCA section 4(a)(1)(B) Proposed Test Rule for In Vitro Dermal
Absorption Rate Testing of Certain Chemicals of Interest to OSHA
submitted to the TSCA Public Docket Office, USEPA. July 17, 1999.
27. People for the Ethical Treatment of Animals. Comments on EPA's
TSCA section 4(a)(1)(B) Proposed Test Rule for In Vitro Dermal
Absorption Rate Testing of Certain Chemicals of Interest to OSHA
submitted to the TSCA Public Docket Office, USEPA. July 30, 1999.
28. Animal Protection Institute, Midwest Regional Office. Comments
on EPA's TSCA section 4(a)(1)(B) Proposed Test Rule for In Vitro Dermal
Absorption Rate Testing of Certain Chemicals of Interest to OSHA
submitted to the TSCA Public Docket Office, USEPA. August 4, 1999.
29. Humane Society of the United States. Comments on EPA's TSCA
section 4(a)(1)(B) Proposed Test Rule for In Vitro Dermal Absorption
Rate Testing of Certain Chemicals of Interest to OSHA submitted to the
TSCA Public Docket Office, USEPA. August 9, 1999.
30. Doris Day Animal League. Comments on EPA's TSCA section
4(a)(1)(B) Proposed Test Rule for In Vitro Dermal Absorption Rate
Testing of Certain Chemicals of Interest to OSHA submitted to the TSCA
Public Docket Office, USEPA. August 9, 1999.
31. Chlorobenzene Producers Association. Comments on EPA's TSCA
section 4(a)(1)(B) Proposed Test Rule for In Vitro Dermal Absorption
Rate Testing of Certain Chemicals of Interest to OSHA submitted to the
TSCA Public Docket Office, USEPA. August 9, 1999.
32. Tetrahydrofuran Task Force. Comments on EPA's TSCA section
4(a)(1)(B) Proposed Test Rule for In Vitro Dermal Absorption Rate
Testing of Certain Chemicals of Interest to OSHA submitted to the TSCA
Public Docket Office, USEPA. August 9, 1999.
33. Private Citizen. Comments on EPA's TSCA section 4(a)(1)(B)
Proposed Test Rule for In Vitro Dermal Absorption Rate Testing of
Certain Chemicals of Interest to OSHA submitted to the TSCA Public
Docket Office, USEPA. June 15, 1999.
34. ACC Naphthalene Panel. Comments on EPA's TSCA section
4(a)(1)(B) Proposed Test Rule for In Vitro Dermal Absorption Rate
Testing of Certain Chemicals of Interest to OSHA submitted to the TSCA
Public Docket Office, USEPA. August 9, 1999.
35. ACC Propylene Glycol Ethers Panel. Comments on EPA's TSCA
section 4(a)(1)(B) Proposed Test Rule for In Vitro Dermal Absorption
Rate Testing of Certain Chemicals of Interest to OSHA submitted to the
TSCA Public Docket Office, USEPA. August 6, 1999.
36. ACC Olefins Panel. Comments on EPA's TSCA section 4(a)(1)(B)
Proposed Test Rule for In Vitro Dermal Absorption Rate Testing of
Certain Chemicals of Interest to OSHA submitted to the TSCA Public
Docket Office, USEPA. August 9, 1999.
37. ACC Hydrocarbon Solvents Panel. Comments on EPA's TSCA section
4(a)(1)(B) Proposed Test Rule for In Vitro Dermal Absorption Rate
Testing of Certain Chemicals of Interest to OSHA submitted to the TSCA
Public Docket Office, USEPA. August 9, 1999.
38. ACC Ketones Panel and Oxo Process Panel. Comments on EPA's TSCA
section 4(a)(1)(B) Proposed Test Rule for In Vitro Dermal Absorption
[[Page 22433]]
Rate Testing of Certain Chemicals of Interest to OSHA submitted to the
TSCA Public Docket Office, USEPA. August 9, 1999.
39. ACC Carbon Disulfide Panel. Comments on EPA's TSCA section
4(a)(1)(B) Proposed Test Rule for In Vitro Dermal Absorption Rate
Testing of Certain Chemicals of Interest to OSHA submitted to the TSCA
Public Docket Office, USEPA. August 9, 1999.
40. Buell, D.A., Blaustein, M.B., and Lynch, J.R. An Assessment of
the National Occupational Exposure Survey. Prepared by Temple, Barker &
Sloane, Inc. and Exxon Corp. Undated.
41. Seta, J.A., Sundin, D.S., and Pedersen, D.H. National
Occupational Exposure Survey Field Guidelines. National Institute for
Occupational Safety and Health, Cincinnati, OH. DHHS (NIOSH)
Publication No. 88-106. 1988.
42. USEPA, Office of Research and Development. Dermal Exposure
Assessment: Principles and Applications. EPA/600/8-91/011B. January
1992.
43. USEPA. Voluntary Children's Chemical Evaluation Program.
Federal Register (65 FR 81699, December 26, 2000) (FRL-6758-5).
44. OECD, Paris. Guidance Document for the Conduct of In Vitro Skin
Absorption Studies. (Draft). April 1999.
45. Harrison, S.M., Barry, B.W., and Dugard, P.H. Effects of
freezing on human skin permeability. Journal of Pharmacy and
Pharmacology. 36: 261. 1984.
46. USEPA. Laboratory Capacity and the HPV Challenge Program. OPPT/
EETD/EPAB, Washington, DC. October 14, 1999.
47. Union Carbide Corporation (now Dow Corporation). A letter from
Dr. Imogene Treble to Frank Kover, USEPA transmitting a study entitled
Primary Amyl Acetate, Mixed Isomers: In Vitro Percutaneous Absorption
Study in Human Skin. July 5, 2000.
48. USEPA. Proposed Test Rule for Hazardous Air Pollutants. Federal
Register (61 FR 33178, June 26, 1996) (FRL-4869-1).
49. National Institute for Occupational Safety and Health. National
Occupational Exposure Survey. March 29, 1989.
50. Riviere, J.E., Brooks, J.D., Qiao, G.L., and Monteiro-Riviere,
N.A. Percutaneous Absorption of Volatile Chemicals. Prepared by North
Carolina State University, Raleigh, NC for AFSOR/NL, Bolling AFB,
Washington, DC. NTIS number ADA332910. November 1997.
51. USEPA. Data Collection and Development on High Production
Volume (HPV) Chemicals. Federal Register (65 FR 81686, December 26,
2000) (FRL-6754-6).
52. USEPA. EPA Census of TSCA Testing Laboratories. Prepared by
OPPT, EETD, EPAB, Washington, DC. October 10, 1996.
53. USEPA. Analysis of U.S. Laboratory Capacity for Developmental
and Reproductive Toxicity Testing and the Impact of Expanded TSCA Test
Rules. Prepared by OPPT/EETD/EPAB, Washington, DC. May 28, 1999.
54. USEPA. ChemRTK, HPV Challenge Program Chemical List. Prepared
by OPPT. (This list is updated periodically, and is available
electronically at http://www.epa.gov/chemrtk/hpvchmlt.htm)
55. USEPA. TSCA section 4(a)(1)(B) Final Statement of
Policy.Federal Register (58 FR 28736, May 14, 1993) (FRL-4059-9).
56. USEPA. Information on OSHA Dermal Test Rule Chemicals: TRI
Release Data and Number of Workers Exposed. Prepared by OPPT/EETD/
Chemical Engineering Branch (CEB), Washington, DC. April 24, 2001 and
March 1998.
57. USEPA. Economic Impact Analysis and Small Entity Impact
Analysis of the TSCA Section 4(a) Test Rule for 34 Chemicals Targeted
for In Vitro Dermal Absorption Rate Testing. Prepared by OPPT/EETD/
EPAB, Washington, DC. February 3, 2004.
58. USEPA. Guidelines for Exposure Assessment. Federal Register (57
FR 22888, May 29, 1992) (FRL-4129-5).
59. Small Business Administration, Office of Size Standards. Small
Business Size Standards matched to North American Industry
Classification System (NAICS). On website: http://www.sba.gov/size/sizetable2002.html.
60. USEPA. Treatment of 12(b) Export Notification Unit Costs for
section 4 Test Rule Analyses. Prepared by Lynne Blake-Hedges OPPT/EETD/
EPAB, Washington, DC. April 1, 1999.
61. USEPA. Economic Analysis in Support of the TSCA 12(b)
Information Collection Request. Prepared by Joseph Callahan OPPT/EETD/
EPAB, Washington, DC. October 30, 1998.
62. OSHA. OSHA dermal test rule. Electronic mail from Val Schaeffer
to Keith Cronin, USEPA. May 22, 2000.
63. OSHA. Dermal rule. Electronic mail from Val Schaeffer to Keith
Cronin, USEPA. March 20, 2002.
64. OSHA. Dermal rule. Electronic mail from Val Schaeffer to Keith
Cronin, USEPA. August 25, 2000.
65. Scheuplein, R.J. and Blank, I.H. Mechanism of percutaneous
absorption. IV. Penetration of nonelectrolytes (alcohols) from aqueous
solutions and from pure liquids. Journal of Investigative Dermatology.
60:286-296. 1973.
66. USEPA. Wage Rates for Economic Analysis of the Toxics Release
Inventory Program. Prepared by Cody Rice, Analytical Support Branch,
Environmental Analysis Division, Office of Environmental Information.
April 11, 2002.
67. USEPA. Review of comments received on proposed dermal
absorption test rule. Memorandum from Greg Macek, CEB to Keith Cronin,
Chemical Control Division. October 8, 1999.
68. USEPA. Office of Water Chemicals; Final Test Rule.Federal
Register (58 FR 59667, November 10, 1993) (FRL-4047-2).
69. USEPA. Testing Consent Agreements and Test Rules; Final
Rule.Federal Register (55 FR 18881, May 7, 1990) (FRL-3687-6).
70. USEPA. Amended Proposed Test Rule for Hazardous Air Pollutants;
Extension of Comment Period. Federal Register (62 FR 67465, December
24, 1997) (FRL-5742-2).
71. USEPA. Inventory Reporting Requirements; Final Rule. Federal
Register (42 FR 64571, December 23, 1977) (FRL-817-1).
72. USEPA. Office of Solid Waste Chemicals; Final Test Rule.Federal
Register (53 FR 22300, June 15, 1988) (FRL-3396-8).
73. USEPA. Amended Proposed Test Rule for Hazardous Air Pollutants;
Extension of Comment Period. Federal Register (63 FR 19694, April 21,
1998) (FRL-5780-6).
74. USEPA. Toxic Substances; Test Rule Development and Exemption
Procedures. Federal Register (50 FR 20652, May 17, 1985) (FRL-2809-7).
75. USEPA. Methylcyclopentane and Commercial Hexane; Proposed Test
Rule. Federal Register (51 FR 17854, May 15, 1986) (FRL-3008-8).
76. USEPA. Commercial Hexane and Methylcyclopentane; Final Test
Rule. Federal Register (53 FR 3382, February 5, 1988) (FRL-3325-1).
77. USEPA. Toxic Substances; Biphenyl; Final Test Rule.Federal
Register (50 FR 37182, September 12, 1985) (FRL-2871-5).
78. USEPA. Office of Water Chemicals, Final Test Rule;
Clarification. Federal Register (59 FR 45629, September 2, 1994) (FRL-
4047-2).
79. USEPA. Toxic Substances Control Act; Data Reimbursement.Federal
Register (48 FR 31785 July 11, 1983) (FRL-2349-8).
[[Page 22434]]
X. Statutory and Executive Order Reviews
A. Paperwork Reduction Act
The information collection requirements contained in TSCA section 4
test rules have already been approved by OMB under the provisions of
the Paperwork Reduction Act, 44 U.S.C. 3501 et seq., and have been
assigned OMB control number 2070-0033 (EPA ICR No. 1139). The
information collection activities related to export notification under
TSCA section 12(b)(1) are already approved under OMB control number
2070-0030 (EPA ICR No. 0795). This final rule does not contain any new
or amended requirements that would require additional review and/or
approval by OMB.
The standard chemical testing program involves the submission of
letters of intent to test (or exemption applications), study plans,
progress reports, and test results. EPA estimates that the information
collection activities related to chemical testing for all chemicals in
this final rule (representing the submission of letters of intent or
exemption applications, study plans, and the final reports; progress
reports are not required by this final rule because testing will be
completed within about 1 year) would result in an annual public
reporting burden of 165 hours per chemical or a total of 5,610 hours
for the 34 chemicals (Ref. 57).
The annual public reporting burden related to export notification
is estimated to be 0.5 to 1.5 burden hours for each chemical/country
combination (Ref. 57). In estimating the total burden hours approved
for the information collection activities related to export
notification, the Agency has included sufficient burden hours to
accommodate any export notifications that may be required by the
Agency's issuance of final chemical test rules (Refs. 57, 60, and 61).
For each manufacturer of the 34 chemicals identified in the
economic analysis, the parent company (ultimate corporate entity, or
UCE) was also identified. The economic analysis identified a total of
84 UCEs that EPA believes would be the likely respondents to the final
rule. The public reporting burden for this collection of information is
estimated to average 165 hours per chemical. Multiplying by 34
chemicals (34 x 165 = 5,610 hours total), and dividing by 84 UCEs,
results in a per respondent estimated burden of 66.8 hours. This burden
estimate includes time for reviewing instructions, searching existing
data sources, gathering and maintaining the data needed, and completing
and reviewing the collection of information.
As defined by PRA and 5 CFR 1320.3(b), ``burden'' means the total
time, effort, or financial resources expended by persons to generate,
maintain, retain, or disclose or provide information to or for a
Federal Agency. This includes the time needed to: Review instructions;
develop, acquire, install, and utilize technology and systems for the
purposes of collecting, validating, and verifying information,
processing and maintaining information, and disclosing and providing
information; adjust the existing ways to comply with any previously
applicable instructions and requirements which have subsequently
changed; train personnel to be able to respond to a collection of
information; search data sources; complete and review the collection of
information; and transmit or otherwise disclose the information.
Under PRA, an agency may not conduct or sponsor, and a person is
not required to respond to, an information collection request unless it
displays a currently valid OMB control number. The OMB control numbers
for EPA's regulations are listed in 40 CFR part 9 and included on the
related collection instrument. EPA is amending the table in 40 CFR part
9 to list the OMB approval number for the information collection
requirements contained in this final rule. This listing of the OMB
control numbers and their subsequent codification in the CFR satisfies
the display requirements of PRA and OMB's implementing regulations at 5
CFR part 1320. This ICR was previously subject to public notice and
comment prior to OMB approval, and given the technical nature of the
table, EPA finds that further notice and comment to amend it is
unnecessary. As a result, EPA finds that there is ``good cause'' under
section 553(b)(1)(B) of the Administrative Procedure Act, 5 U.S.C.
553(b)(1)(B), to amend this table without further notice and comment.
B. Regulatory Flexibility Act (RFA)
Pursuant to section 605(b) of the Regulatory Flexibility Act (RFA),
5 U.S.C. 601 et seq., the Agency hereby certifies that this final rule
will not have a significant adverse economic impact on a substantial
number of small entities. The factual basis for the Agency's
determination is presented in the small entity impact analysis prepared
as part of the economic analysis for this final rule (Ref. 57), and is
briefly summarized here.
Three factors are examined in EPA's small entity assessment (Ref.
57) in order to characterize the potential small entity impacts of this
final rule:
The size of the adverse impact (measured as the
ratio of the cost to sales or revenue).
The total number of small entities that
experience the adverse impact.
The percentage of the total number of small
entities that experience the adverse impact.
Section 601(3) of RFA establishes as the default definition of
``small business'' the definition used in section 3 of the Small
Business Act, 15 U.S.C. 632, under which the SBA establishes small
business size standards for each industry sector. (13 CFR 121.201). For
this final rule, EPA has analyzed the potential small business impacts
using the size standards established under this default definition. The
SBA size standards, which are primarily intended to determine whether a
business entity is eligible for government programs and preferences
reserved for small businesses (13 CFR 121.101), ``seek to ensure that a
concern that meets a specific size standard is not dominant in its
field of operation.'' (13 CFR 121.102(b)). See section 632(a)(1) of the
Small Business Act. Industrial sectors are identified by a NAICS code.
In most cases, SBA has specified an employee size standard (100; 500;
750; 1,000; or 1,500 employees) or, in some cases, a sales-based, or
other industry-specific indicator, cut-off below which an entity in
that particular NAICS code would be considered small (Ref. 59).
The SBA employee size standards that apply to most of the NAICS
codes that are potentially impacted (Ref. 57) by this final rule range
from 500 to 1,500 employees. Size standards for three potentially
affected non-manufacturing NAICS are defined in terms of sales, and in
each case the standards are $5 million in annual sales, while the
standards for the set of possible NAICS where another entity is likely
to fall, are expressed in terms of electricity generating capacity (4
million megawatt hours).
Sales and employment data were obtained for the 84 UCEs that
manufacture the 34 chemicals subject to this final rule to identify
those UCEs that qualify for ``small business'' status, where data were
available. Based on the SBA size standards for the NAICS codes that
applied to those UCEs, 25 of the 84 UCEs (30%) were identified as
small. The significance of this final rule's impact on these small
businesses was analyzed by examining the number of small entities that
experienced different levels of costs as a percentage of their sales.
In such an analysis, small businesses are placed in the following
[[Page 22435]]
categories on the basis of cost-to-sales ratios: less than 1.0%, 1.0%
but less than 3.0%, and 3.0% or greater. Of the 25 companies that
qualified for small business status according to the SBA size
standards, none had a cost-to-sales ratio that exceeded 1.0%. Given
these results, EPA concludes that there is not a significant economic
impact on these small entities as a result of this final rule.
There were an additional seven UCEs for which the NAICS code,
sales, and employment data were not available. Because of this, EPA
could not determine whether they are small businesses or assess the
potential impacts of the test rule on them. However, it is very
unlikely that all seven of these UCEs are small entities. Moreover,
given the Agency's analysis for the identified small businesses, which
concluded that there is not a significant economic impact on any of
them, EPA believes it is reasonable to conclude that even if some of
these seven UCEs are small entities, they will not experience a
significant economic impact. Consequently, EPA concludes that there
will not be a significant economic impact on a substantial number of
small entities as a result of this final rule.
In analyzing potential impacts on small entities, RFA recognizes
that it may be appropriate at times to use an alternate definition of
small business. As such, section 601(3) of RFA provides that an agency
may establish a different definition of small business after
consultation with the SBA Office of Advocacy and after notice and an
opportunity for public comment. Even though the Agency has used the
default SBA definition of small business to conduct its analysis of
potential small entity impacts for this final rule, EPA does not
believe that the SBA size standards are generally the best standards to
use in assessing potential impacts of TSCA section 4(a) test rules on
small entities. EPA believes that a standard based on total annual
sales, such as the definition found in TSCA (40 CFR 704.3), may provide
a more appropriate means to determine the ability of a chemical
manufacturing firm to support testing without significant costs or
burdens. EPA is determining what level of annual sales would provide
the most appropriate size cutoff with regard to various segments of the
chemical industry usually impacted by TSCA section 4(a) test rules, but
has not yet reached a determination. Therefore, as previously stated in
this unit, the RFA determination for this final rule is based on an
analysis using the default SBA size standards. In the proposal to this
rule, EPA requested comment on whether the Agency should establish an
alternate small business definition to use in small entity impact
analyses for future TSCA section 4(a) test rules, and what size cutoff
may be appropriate. The comment received on this subject and the
Agency's response are in Unit III.K.
Although EPA has not yet pursued the establishment of an alternate
definition for use in the analysis conducted for this final rule, the
analysis does present the results of calculations using a standard
based on total annual sales. Under the TSCA definition at 40 CFR 704.3,
a firm is classified as small if it has either total annual sales below
$40 million and annual production or importation volume less than or
equal to 100,000 pounds, or, annual sales below $4 million. Of the 84
UCEs subject to the final rule, a maximum of 9 can be classified as
small under the TSCA definition, with data unavailable for an
additional 7 firms. None of those 9 firms will be affected at the level
of 1.0% or greater. Impacts could not be determined for the 7 firms
whose size was unknown, but as with the analysis conducted using the
SBA size standards, the Agency believes it is reasonable to conclude
that under the referenced TSCA definition of small, the 7 UCEs will not
experience significant economic impacts as a result of the final rule.
The estimated costs of the TSCA section 12(b) export notification,
which, as a result of this final rule, would be required for the first
export to a particular country of a chemical subject to the rule, is
estimated to be $61.31 for the first time that an exporter must comply
with TSCA section 12(b) export notification requirements, and $18.07
for each subsequent export notification submitted by that exporter
(Refs. 57, 60, and 61). EPA has concluded that the costs of TSCA
section 12(b) export notification would have a negligible impact on
exporters of the chemicals in this final rule, regardless of the size
of the exporter.
Therefore, the Agency certifies that this final rule will not have
a significant adverse economic impact on a substantial number of small
entities.
C. Unfunded Mandates Reform Act
Pursuant to Title II of the Unfunded Mandates Reform Act of 1995
(Public Law 104-4), EPA has determined that this regulatory action does
not contain a Federal mandate that may result in expenditures of $100
million or more for State, local, and tribal governments, in the
aggregate, or for the private sector in any 1 year. The analysis of the
costs associated with this action are described in Unit VIII. In
addition, since EPA does not have any information to indicate that any
State, local, or tribal government manufactures or processes the
chemicals covered by this action such that this final rule would apply
directly to State, local, or tribal governments, EPA has determined
that this final rule does not significantly or uniquely affect small
governments. Accordingly, this final rule is not subject to the
requirements of sections 202, 203, 204, and 205 of UMRA.
D. Executive Order 13132
Executive Order 13132, entitled Federalism (64 FR 43255, August 10,
1999), requires EPA to develop an accountable process to ensure
``meaningful and timely input by State and local officials in the
development of regulatory policies that have federalism implications.''
``Policies that have federalism implications'' is defined in the
Executive order to include regulations that have ``substantial direct
effects on the States, on the relationship between the national
government and the States, or on the distribution of power and
responsibilities among the various levels of government.''
This final rule does not have federalism implications. It will not
have substantial direct effects on the States, on the relationship
between the national government and the States, or on the distribution
of power and responsibilities among the various levels of government,
as specified in Executive Order 13132. This final rule establishes
testing and recordkeeping requirements that apply to manufacturers
(including importers) and processors of certain chemicals. Because EPA
has no information to indicate that any State or local government
manufactures or processes the chemical substances covered by this
action, this final rule does not apply directly to States and
localities and will not affect State and local governments. Thus,
Executive Order 13132 does not apply to this final rule. Although
Executive Order 13132 was not yet in effect when EPA developed the
proposed rule, its predecessor, Executive Order 12875, was and EPA's
conclusions under Executive Order 13132 are consistent with EPA's
considerations under Executive Order 12875.
E. Executive Order 13175
Under Executive Order 13175, entitled Consultation and Coordination
with Indian Tribal Governments (65 FR 67249, November 6, 2000), this
final rule does not have tribal implications
[[Page 22436]]
because it will not have substantial direct effects on tribal
governments, on the relationship between the Federal Government and the
Indian tribes, or on the distribution of power and responsibilities
between the Federal Government and Indian tribes, as specified in the
Order. As indicated above, EPA has no information to indicate that any
tribal government manufactures or processes the chemical substances
covered by this action. Thus, Executive Order 13175 does not apply to
this final rule. Although Executive Order 13175 was not yet in effect
when EPA developed the proposed rule, its predecessor, Executive Order
13084, was and EPA's conclusions under Executive Order 13175 are
consistent with EPA's considerations under Executive Order 13084.
F. Executive Order 13045
This final rule does not require special consideration pursuant to
the terms of Executive Order 13045, entitled Protection of Children
from Environmental Health Risks and Safety Risks (62 FR 19885, April
23, 1997), because it is not likely to have an annual effect on the
economy of $100 million or more and it does not have a potential effect
or impact on children. This final rule establishes testing and
recordkeeping requirements that apply to manufacturers (including
importers) and processors of certain chemicals, and will result in the
production of information that will assist the Agency and others in
determining whether the chemical substances in this final rule present
potential risks, allowing the Agency and others to take appropriate
action to investigate and mitigate those risks.
G. Executive Order 13211
This final rule is not a ``significant energy action'' as defined
in Executive Order 13211, Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use (66 FR 28355,
May 22, 2001) because it is not likely to have a significant adverse
effect on the supply, distribution, or use of energy. As such, the
Agency has concluded that this final rule is not likely to have adverse
energy effects.
H. National Technology Transfer and Advancement Act
As noted in the proposed rule, section 12(d) of the National
Technology Transfer and Advancement Act of 1995 (NTTAA), Public Law
104-113 section 12(d) (15 U.S.C 272 note) directs EPA to use voluntary
consensus standards in its regulatory activities unless to do so would
be inconsistent with applicable law or otherwise impractical. Voluntary
consensus standards are technical standards (e.g., materials
specifications, test methods, sampling procedures, and business
practices) that are developed or adopted by voluntary consensus
standards bodies. The NTTAA directs EPA to provide Congress, through
OMB, explanations when the Agency decides not to use available and
applicable voluntary consensus standards.
Because this final rule involves technical standards, the Agency
conducted a search to identify potentially applicable voluntary
consensus standards. No such standards were identified and none were
brought to the Agency's attention in comments. Therefore, EPA has
decided to use the in vitro dermal absorption rate test standard
finalized in this document. This standard was based on the peer
reviewed method of Bronaugh and Collier which was published in 1991
(Ref. 13) and refined by a panel of Federal scientists from ITC member
and liaison agencies (including, for example, CPSC, DoD, EPA, FDA,
NIOSH, and OSHA). The method was further refined by this panel in
response to public comments.
I. Executive Order 12898
Pursuant to Executive Order 12898, entitled Federal Actions to
Address Environmental Justice in Minority Populations and Low-Income
Populations (59 FR 7629, February 16, 1994), the Agency has considered
environmental justice-related issues with regard to the potential
impacts of this action on the environmental and health conditions in
minority and low-income populations. The Agency believes that the
information collected under this final rule will assist EPA and others
in determining the hazards and risks associated with the chemicals
covered by the final rule. Although not directly impacting
environmental justice-related concerns, this information will better
enable the Agency to protect human health and the environment.
J. Congressional Review Act
The Congressional Review Act, 5 U.S.C. 801 et seq., generally
provides that before a rule may take effect, the Agency promulgating
the rule must submit a rule report to each House of the Congress and
the Comptroller General of the United States. EPA will submit a report
containing this rule and other required information to the U.S. Senate,
the U.S. House of Representatives, and the Comptroller General of the
United States prior to publication of the rule in the Federal Register.
This rule is not a ``major rule'' as defined by 5 U.S.C. 804(2).
List of Subjects
40 CFR Part 9
Environmental protection, Reporting and recordkeeping requirements.
40 CFR Part 799
Environmental protection, Chemicals, Hazardous substances,
Laboratories, Reporting and recordkeeping requirements.
Dated: April 4, 2004.
Susan B. Hazen,
Acting Assistant Administrator, Office of Prevention, Pesticides and
Toxic Substances.
0
Therefore, 40 CFR chapter I is amended as follows:
0
1. By amending part 9 as follows:
PART 9--[AMENDED]
0
a. The authority citation for part 9 continues to read as follows:
Authority: 7 U.S.C. 135 et seq., 136-136y; 15 U.S.C. 2001, 2003,
2005, 2006, 2601-2671; 21 U.S.C. 331j, 346a, 348; 31 U.S.C. 9701; 33
U.S.C. 1251 et seq., 1311, 1313d, 1314, 1318, 1321, 1326, 1330,
1342, 1344, 1345 (d) and (e), 1361; E.O. 11735, 38 FR 21243, 3 CFR,
1971-1975 Comp. p. 973; 42 U.S.C. 241, 242b, 243, 246, 300f, 300g,
300g-1, 300g-2, 300g-3, 300g-4, 300g-5, 300g-6, 300j-1, 300j-2,
300j-3, 300j-4, 300j-9, 1857 et seq., 6901-6992k, 7401-7671q, 7542,
9601-9657, 11023, 11048.
0
b. In Sec. 9.1, the table is amended by adding an entry for Sec.
799.5115 in numerical order under the indicated heading to read as
follows:
Sec. 9.1 OMB approvals under the Paperwork Reduction Act.
* * * * *
------------------------------------------------------------------------
OMB control
40 CFR citation No.
------------------------------------------------------------------------
* * * * *
Identification of Specific Chemical Substance and Mixture Testing
Requirements
------------------------------------------------------------------------
* * * * *
799.5115................................................ 2070-0033
* * * * *
------------------------------------------------------------------------
* * * * *
0
2. By amending part 799 as follows:
PART 799--[AMENDED]
0
a. The authority citation for part 799 continues to read as follows:
Authority: 15 U.S.C. 2603, 2611, 2625.
0
b. By adding Sec. 799.5115 to subpart D to read as follows:
[[Page 22437]]
Sec. 799.5115 Chemical testing requirements for certain chemicals of
interest to the Occupational Safety and Health Administration.
(a) What substances will be tested under this section? Table 2 in
paragraph (j) of this section identifies the chemical substances that
must be tested under this section. For the chemical substances
identified as ``Class 1'' substances in Table 2 in paragraph (j) of
this section, the purity of each chemical substance must be 99% or
greater, unless otherwise specified in this section. For the chemical
substances identified as ``Class 2'' substances in Table 2 in paragraph
(j) of this section, a representative form of each chemical substance
must be tested.
(b) Am I subject to this section? (1) If you manufacture (including
import) or intend to manufacture, or process or intend to process, any
chemical substance listed in Table 2 in paragraph (j) of this section
at any time from May 26, 2004, to the end of the test data
reimbursement period as defined in 40 CFR 791.3(h), you are subject to
this section with respect to that chemical substance.
(2) If you do not know or cannot reasonably ascertain that you
manufacture or process a chemical substance listed in Table 2 in
paragraph (j) of this section during the time period described in
paragraph (b)(1) of this section (based on all information in your
possession or control, as well as all information that a reasonable
person similarly situated might be expected to possess, control, or
know, or could obtain without an unreasonable burden), you are not
subject to this section with respect to that chemical substance.
(c) If I am subject to this section, when must I comply with it?
(1)(i) Persons subject to this section are divided into two groups, as
set forth in Table 1 of this paragraph: Tier 1 (persons initially
required to comply) and Tier 2 (persons not initially required to
comply). If you are subject to this section, you must determine if you
fall within Tier 1 or Tier 2, based on Table 1 of this paragraph.
Table 1.--Persons Subject to the Rule: Persons in Tier 1 and Tier 2
------------------------------------------------------------------------
Persons not initially required
Persons initially required to comply to comply with this section
with this section (Tier 1) (Tier 2)
------------------------------------------------------------------------
Persons not otherwise specified in A. Persons who manufacture (as
column 2 of this table that defined at TSCA section 3(7))
manufacture (as defined at TSCA or intend to manufacture a
section 3(7)) or intend to manufacture chemical substance included in
a chemical substance included in this this section solely as one or
section. more of the following:
--As a byproduct (as defined at
40 CFR 791.3(c));
--As an impurity (as defined at
40 CFR 790.3);
--As a naturally occurring
substance (as defined at 40
CFR 710.4(b));
--As a non-isolated
intermediate (as defined at 40
CFR 704.3);
--As a component of a Class 2
substance (as described at 40
CFR 720.45(a)(1)(i));
--In amounts of less than 500
kilograms (kg) (1,100 lbs)
annually (as described at 40
CFR 790.42(a)(4)); or
--For research and development
(as described at 40 CFR
790.42(a)(5)).
B. Persons who process (as
defined at TSCA section 3(10))
or intend to process a
chemical substance included in
this section (see 40 CFR
790.42(a)(2)).
------------------------------------------------------------------------
(ii) Table 1 in paragraph (c)(1)(i) of this section expands the
list of persons specified in Sec. 790.42(a)(2), (a)(4), and (a)(5) of
this chapter, who, while legally subject to this section, must comply
with the requirements of this section only if directed to do so by EPA
under the circumstances set forth in paragraphs (c)(4) through (c)(7)
and (c)(10) of this section.
(2) If you are in Tier 1 with respect to a chemical substance
listed in Table 2 in paragraph (j) of this section, you must, for each
test required under this section for that chemical substance, either
submit to EPA a letter of intent to test or apply to EPA for an
exemption from testing. The letter of intent to test or the exemption
application must be received by EPA no later than June 25, 2004.
(3) If you are in Tier 2 with respect to a chemical substance
listed in Table 2 in paragraph (j) of this section, you are considered
to have an automatic conditional exemption and you will be required to
comply with this section with regard to that chemical substance only if
directed to do so by EPA under paragraphs (c)(5), (c)(7), or (c)(10) of
this section.
(4) If no person in Tier 1 has notified EPA of its intent to
conduct one or more of the tests required by this section on any
chemical substance listed in Table 2 in paragraph (j) of this section
by June 25, 2004, EPA will publish a Federal Register document that
would specify the test(s) and the chemical substance(s) for which no
letter of intent has been submitted, and notify manufacturers in Tier
2A of their obligation to submit a letter of intent to test or to apply
for an exemption from testing.
(5) If you are in Tier 2A with respect to a chemical substance
listed in Table 2 in paragraph (j) of this section, and if you
manufacture this chemical substance as of May 26, 2004, or within 30
days after publication of the Federal Register document described in
paragraph (c)(4) of this section, you must, for each test specified for
that chemical substance in the document described in paragraph (c)(4)
of this section, either submit to EPA a letter of intent to test or
apply to EPA for an exemption from testing. The letter of intent to
test or the exemption application must be received by EPA no later than
30 days after publication of the document described in paragraph (c)(4)
of this section.
(6) If no manufacturer in Tier 1 or Tier 2A has notified EPA of its
intent to conduct one or more of the tests required by this section on
any chemical substance listed in Table 2 in paragraph (j) of this
section within 30 days after the publication of the Federal Register
document described in paragraph (c)(4) of this section, EPA will
publish another Federal Register document that would specify the
test(s) and the chemical substance(s) for which no letter of intent has
been submitted, and notify processors in Tier 2B of their obligation to
submit a letter of intent to test or to apply for an exemption from
testing.
(7) If you are in Tier 2B with respect to a chemical substance
listed in Table 2 in paragraph (j) of this section, and if you process
this chemical substance as of May 26, 2004, or within 30 days after
publication of the Federal Register document described in paragraph
(c)(6) of this section, you must, for each test specified for that
chemical substance in the document described in paragraph (c)(6) of
this section, either submit to EPA a letter of intent to test or apply
to EPA for an exemption from testing. The
[[Page 22438]]
letter of intent to test or the exemption application must be received
by EPA no later than 30 days after publication of the document
described in paragraph (c)(6) of this section.
(8) If no manufacturer or processor has notified EPA of its intent
to conduct one or more of the tests required by this section for any of
the chemical substances listed in Table 2 in paragraph (j) of this
section within 30 days after the publication of the Federal Register
document described in paragraph (c)(6) of this section, EPA will notify
all manufacturers and processors of those chemical substances of this
fact by certified letter or by publishing a Federal Register document
specifying the test(s) for which no letter of intent has been
submitted. This letter or Federal Register document will additionally
notify all manufacturers and processors that all exemption applications
concerning the test(s) have been denied, and will give the
manufacturers and processors of the chemical substance(s) an
opportunity to take corrective action.
(9) If no manufacturer or processor has notified EPA of its intent
to conduct one or more of the tests required by this section for any of
the chemical substances listed in Table 2 in paragraph (j) of this
section within 30 days after receipt of the certified letter or
publication of the Federal Register document described in paragraph
(c)(8) of this section, all manufacturers and processors subject to
this section with respect to that chemical substance who are not
already in violation of this section will be in violation of this
section.
(10) If a problem occurs with the initiation, conduct, or
completion of the required testing or the submission of the required
data with respect to a chemical substance listed in Table 2 in
paragraph (j) of this section, under the procedures in Sec. Sec.
790.93 and 790.97 of this chapter, EPA may initiate termination
proceedings for all testing exemptions with respect to that chemical
substance and may notify persons in Tier 1 and Tier 2 that they are
required to submit letters of intent to test or exemption applications
within a specified period of time.
(11) If you are required to comply with this section, but your
manufacturing or processing of a chemical substance listed in Table 2
in paragraph (j) of this section begins after the applicable compliance
date referred to in paragraphs (c)(2), (c)(5), (c)(7), or (c)(10) of
this section, you must either submit a letter of intent to test or
apply to EPA for an exemption. The letter of intent to test or the
exemption application must be received by EPA no later than the day you
begin manufacturing or processing.
(d) What must I do to comply with this section? (1) To comply with
this section you must either submit to EPA a letter of intent to test,
or apply to and obtain from EPA an exemption from testing.
(2) For each test with respect to which you submit to EPA a letter
of intent to test, you must conduct the testing specified in paragraph
(h) of this section and submit the test data to EPA.
(3) You must also comply with the procedures governing test rule
requirements in part 790 of this chapter, as modified by this section,
including the submission of letters of intent to test or exemption
applications, the conduct of testing, and the submission of data; Part
792--Good Laboratory Practice Standards of this chapter; and this
section. The following provisions of 40 CFR part 790 do not apply to
this section: Paragraphs (a), (d), (e), and (f) of Sec. 790.45;
paragraph (a)(2) and paragraph (b) of Sec. 790.80; and Sec. 790.48.
(e) If I do not comply with this section, when will I be considered
in violation of it? You will be considered in violation of this section
as of 1 day after the date by which you are required to comply with
this section.
(f) How are EPA's data reimbursement procedures affected for
purposes of this section? If persons subject to this section are unable
to agree on the amount or method of reimbursement for test data
development for one or more chemical substances included in this
section, any person may request a hearing as described in 40 CFR part
791. In the determination of fair reimbursement shares under this
section, if the hearing officer chooses to use a formula based on
production volume, the total production volume amount will include
amounts of a chemical substance produced as an impurity.
(g) Who must comply with the export notification requirements? Any
person who exports, or intends to export, a chemical substance listed
in Table 2 in paragraph (j) of this section is subject to part 707,
subpart D, of this chapter.
(h) How must I conduct my testing? The chemical substances
identified by Chemical Abstract Service Registry Number (CAS No.) and
chemical name in Table 2 in paragraph (j) of this section must be
tested as follows:
(1) Applicability. This in vitro dermal absorption rate test
standard must be used for all testing conducted under this section. In
certain instances, modifications to the test standard may be
considered. The procedures for applying for a modification to the test
standard are specified in 40 CFR 790.55.
(2) Source. The test standard is based on the Protocol for In Vitro
Percutaneous Absorption Rate Studies, referenced in paragraph (h)(8)(v)
of this section.
(3) Purpose. In the assessment and evaluation of the
characteristics of a chemical substance or mixture for which testing is
required under this section (test substance), it is important to
determine the rate of absorption of the test substance in cases where
dermal exposure to the test substance in the workplace may result in
systemic toxicity. This test standard is designed to develop data that
describe the rate at which test substances are absorbed through the
skin so that the body burden of a test substance resulting from dermal
exposure in the workplace can be better evaluated.
(4) Principles of the test standard. This test standard describes
procedures for measuring a permeability constant (Kp) and two short-
term dermal absorption rates for test substances in liquid form. The
test standard utilizes in vitro diffusion cell techniques which allow
absorption studies to be conducted with human cadaver skin. In vitro
diffusion studies are necessary for measuring a Kp. This test standard
specifies the use of static or flow-through diffusion cells and non-
viable human cadaver skin. It also requires the use of radiolabeled
test substances unless it can be demonstrated that procedures utilizing
a non-radiolabeled test substance are able to measure the test
substance with a sensitivity equivalent to the radiolabeled method.
(5) Test procedure--(i) Choice of membrane--(A) Skin selection.
Human cadaver skin must be used in all testing conducted under this
test standard. This test standard does not require use of live skin, or
the maintenance of skin viability during the course of the experiment.
However, the time elapsed between death and harvest of tissue must be
reported.
(B) Number of skin samples. Data for the determination of a Kp must
be obtained from a minimum of six skin samples and the skin samples
must come from at least three different human subjects (two skin
samples from each subject) in order to allow for biological variation
between subjects. Data for the determination of each short-term (i.e.,
10 minute and 60 minute) absorption rate must be obtained from a
minimum of six skin samples and the skin samples must come from at
least three different human subjects (two skin samples from each
subject).
[[Page 22439]]
(C) Anatomical region. In order to minimize the variability in skin
absorption measurements for these tests, samples of human cadaver skin
must be obtained from the abdominal region of human subjects of known
source and disease state.
(D) Validation of human cadaver skin barrier. Prior to conducting
an experiment with the test substance, barrier properties of human
cadaver skin must be pretested either by:
(1) Measuring the absorption of a standard compound such as
tritiated water as discussed, for example, in the reference in
paragraph (h)(8)(i) of this section;
(2) Determining an electrical resistance to an alternating current,
at up to two volts; or
(3) Measuring trans-epidermal water loss from the stratum corneum.
(ii) Preparation of membrane. Full thickness skin must not be used.
A suitable membrane must be prepared from skin either with a dermatome
at a thickness of 200 to 500 micrometers (um), or with heat separation
by treating the skin at 60[deg] C for 45 seconds to 2 minutes after
which the epidermis can be peeled from the dermis. These epidermal
membranes can be stored frozen (-20[deg] C) for up to 3 months, if
necessary, if they are frozen quickly and the barrier properties of the
samples are confirmed immediately prior to commencement of the
experiment.
(iii) Diffusion cell design. Either static or flow-through
diffusion cells must be used in these studies. To ensure that an
increase in concentration of the test substance in the receptor fluid
does not alter penetration rate, the testing laboratory must verify
that the concentration of the test substance in the receptor fluid is
less than 10% of the initial concentration in the donor chamber.
Concentration of the neat (i.e., undiluted) liquid must be taken as the
density of the test substance.
(iv) Temperature. Skin must be maintained at a physiological
temperature of 32[deg] C during the test.
(v) Testing hydrophobic chemicals. When testing hydrophobic
chemicals, polyethoxyoleate (polyethylene glycol (PEG) 20 oleyl ether)
must be added to the receptor fluid at a concentration of 6%.
(vi) Vehicle. If the test substance is a liquid at room temperature
and does not damage the skin during the determination of Kp, it must be
applied neat. If the test substance cannot be applied neat because it
is a solid at room temperature or because it damages the skin when
applied neat, it must be dissolved in water. If the concentration of a
hydrophobic test substance in water is not high enough so that a
steady-state absorption can be obtained, the test substance must be
dissolved in isopropyl myristate. A sufficient volume of liquid must be
used to completely cover the skin and provide the amount of test
substance as described in paragraph (h)(5)(vii) of this section.
(vii) Dose--(A) Kp. A Kp must be determined for each test chemical.
An ``infinite dose'' of the test substance must be applied to the skin
to achieve the steady-state rate of absorption necessary for
calculation of a Kp. Infinite dose is defined as the concentration of a
test substance required to give an undepletable reservoir on the
surface of the skin. The actual concentration required to give an
undepletable reservoir on the surface of the skin depends on the rate
of penetration of the test substance. Preliminary studies may be
necessary to determine this concentration. Percutaneous absorption must
be determined under occluded (i.e., covered) conditions unless it is
demonstrated that such conditions cause leakage of material or damage
to the skin membrane as a result of unrealistically high pressures or
excessive hydration. Skin barrier integrity must be verified at the end
of the experiment by the methods discussed in paragraph (h)(5)(i)(D) of
this section.
(B) Short-term absorption rates. Short-term absorption rates must
be determined for all test chemicals. The dose of test chemical applied
to the skin must be sufficient to completely cover the exposed skin
surface. A minimum of four diffusion cells must be set up using skin
from a single subject. Two diffusion cells must be terminated at 10
minutes. The remaining two diffusion cells must be terminated at 60
minutes. Skin absorption at each sampling time is the sum of the
receptor fluid levels and the absorbed test substance that remains in
the skin, as discussed, for example, in the reference in paragraph
(h)(8)(iii) of this section. Unabsorbed chemical must be removed from
the skin surface by washing gently with soap and water. This experiment
must be repeated with skin from two additional subjects. In order to
ensure reliable short-term absorption rates, percutaneous absorption
must be determined under occluded conditions unless it is demonstrated
that such conditions cause leakage of material or damage to the skin
membrane as a result of unrealistically high pressures or excessive
hydration.
(viii) Study duration--(A) Kp. The in vitro dermal absorption rate
test must be performed until at least four absorption measurements per
diffusion cell experiment are obtained during the steady-state
absorption portion of the experiment. A preliminary study may be useful
to establish time points for sampling. The required absorption
measurements can be accomplished in an hour or two with fast-
penetrating chemicals but may require 24 hours or longer for slow-
penetrating chemicals. Unabsorbed test substance need not be removed
from the surface of the skin after each experiment.
(B) Short-term absorption rates. The test substance must be applied
to skin for durations of 10 and 60 minutes. At the end of the study,
the unabsorbed test substance must be removed from the surface of the
skin with soap and water and the amount absorbed into the skin and
receptor fluid must be determined, as discussed, for example, in the
reference in paragraph (h)(8)(iii) of this section.
(6) Results--(i) Kp. The Kp must be calculated by dividing the
steady-state rate of absorption (measured in micrograms (ug) x
hr-\1\ x centimeters (cm)-\2\) by the
concentration of the test substance (measured in ug x
cm-\3\) applied to the skin. (For example, if the steady-
state rate is 1 microgram x hr-\1\ x cm-\2\ and
the concentration applied to the skin is 1,000 micrograms x
cm-\3\, then the Kp value is calculated to be 0.001 cm x
hr-\1\.) The mean and standard deviation of the calculated
Kp values for all diffusion cell experiments must be determined.
(ii) Short-term absorption rate. The absorption rates (ug x
hr-\1\ x cm-\2\) must be determined from the
total amount of test substance found in the receptor fluid and skin
after the 10-minute and 60-minute exposures for each diffusion cell
experiment. The mean and standard deviation of 10-minute short-term
absorption rates from all experiments must be calculated. The mean and
standard deviation of 60-minute short-term absorption rates from all
experiments must also be calculated.
(7) Test report. In addition to compliance with the TSCA Good
Laboratory Practice Standards (GLPS) at 40 CFR part 792, the following
specific information must be collected and reported by the date in
paragraph (i) of this section:
(i) Test systems and test methods. (A) A description of the date,
time, and location of the test, the name(s) of the person(s) conducting
the test, the location of records pertaining to the test, as well as a
GLPS statement. These statements must be certified by the signatures of
the individuals performing the work and their supervisors.
[[Page 22440]]
(B) A description of the source, identity, and purity of the test
substance and the source, identity, and handling of the test skin.
There must be a detailed description of the test procedure and all
materials, devices used and doses tested, as well as a detailed
description and illustration of static or flow-through cell design.
There must also be a description of the skin preparation method,
including measurements of the skin membrane thickness.
(C) A description of the analytical techniques to be used,
including their accuracy, precision, and detection limits (in
particular for non-radiolabeled tests), and, if a radiolabel is used,
there must be a description of the radiolabel (e.g., type, location of,
and radiochemical purity of the label).
(D) All data must be clearly identified as to dose and specimen.
Derived values (means, permeability coefficient, graphs, charts, etc.)
are not sufficient.
(ii) Conduct of study. Data must be collected and reported on the
following:
(A) Monitoring of testing parameters.
(B) Temperature of chamber.
(C) Receptor fluid pH.
(D) Barrier property validation.
(E) Analysis of receptor fluid for radioactivity or test chemical
(iii) Results. The mean Kp and mean short-term absorption rates
must be presented along with their standard deviations and the number
of diffusion cell experiments. In addition, all raw data from each
individual diffusion cell must be retained to support the calculations
of permeability constants and short-term absorption rates. When a
radiolabeled test substance is used, a full balance of the
radioactivity must be presented, including cell rinsing and stability
of the test substance in the donor compartment.
(8) References. For background information on this test standard,
the following references may be consulted. These references are
available under docket ID number OPPT-2003-0006 at the EPA Docket
Center, Rm. B102-Reading Room, EPA West, 1301 Constitution Ave., NW.,
Washington, DC, from 8:30 a.m. to 4:30 p.m., Monday through Friday,
excluding legal holidays.
(i) Bronaugh, R.L., Stewart, R.F., and Simon, M. Methods for In
Vitro Percutaneous Absorption Studies VII: Use of Excised Human Skin.
Journal of Pharmaceutical Sciences. 75:1094-1097. 1986.
(ii) Bronaugh, R.L. and Stewart, R.F. Methods for In Vitro
Percutaneous Absorption Studies IV: The Flow-Through Diffusion Cell.
Journal of Pharmaceutical Sciences. 74:64-67. 1985.
(iii) Bronaugh, R.L., Stewart, R.F., and Storm, J.E. Extent of
Cutaneous Metabolism During Percutaneous Absorption of Xenobiotics.
Toxicology and Applied Pharmacology. 99:534-543. 1989.
(iv) Walker, J.D., Whittaker, C. and McDougal, J.N. Role of the
TSCA Interagency Testing Committee in Meeting the U.S. Government Data
Needs: Designating Chemicals for Percutaneous Absorption Rate Testing.
Dermatotoxicology. F. Marzulli and H. Maibach, Eds. Taylor & Francis,
Washington, DC. pp. 371-381. 1996.
(v) Bronaugh, R.L., and Collier, S.W. Protocol for In Vitro
Percutaneous Absorption Studies. In Vitro Percutaneous Absorption:
Principles, Fundamentals, and Applications. R.L. Bronaugh and H.I.
Maibach, Eds. CRC Press, Boca Raton, FL. pp. 237-241. 1991.
(i) Reporting requirements. The reports submitted under this
section must include the information specified in paragraph (h)(7) of
this section. A final report for each chemical substance must be
received by EPA by June 27, 2005, unless an extension is granted in
writing pursuant to 40 CFR 790.55.
(j) Designation of specific chemical substances for testing. The
chemical substances identified by chemical name, CAS No., and class in
Table 2 of this paragraph must be tested in accordance with the testing
requirements in paragraph (h) of this section and the requirements
described in 40 CFR part 792.
Table 2.--Chemical Substances Designated For Testing
------------------------------------------------------------------------
CAS No. Chemical name Class
------------------------------------------------------------------------
75-05-8 Acetonitrile 1
-------------------------------
75-15-0 Carbon disulfide 1
-------------------------------
75-35-4 Vinylidene chloride 1
-------------------------------
77-73-6 Dicyclopentadiene 1
-------------------------------
77-78-1 Dimethyl sulfate 1
-------------------------------
78-59-1 Isophorone 1
-------------------------------
78-87-5 Propylene dichloride 1
-------------------------------
79-20-9 Methyl acetate 1
-------------------------------
79-46-9 2-Nitropropane 1
-------------------------------
91-20-3 Naphthalene 1
-------------------------------
92-52-4 Biphenyl 1
-------------------------------
98-29-3 tert-Butylcatechol 1
-------------------------------
100-00-5 p-Nitrochlorobenzene 1
-------------------------------
100-01-6 p-Nitroaniline 1
-------------------------------
100-44-7 Benzyl chloride 1
-------------------------------
[[Page 22441]]
106-42-3 p-Xylene 1
-------------------------------
106-46-7 p-Dichlorobenzene 1
-------------------------------
107-06-2 Ethylene dichloride 1
-------------------------------
107-31-3 Methyl formate 1
-------------------------------
108-03-2 1-Nitropropane 1
-------------------------------
108-90-7 Chlorobenzene 1
-------------------------------
108-93-0 Cyclohexanol 1
-------------------------------
109-66-0 Pentane 1
-------------------------------
109-99-9 Tetrahydrofuran 1
-------------------------------
110-12-3 Methyl isoamyl ketone 1
-------------------------------
111-84-2 Nonane 1
-------------------------------
120-80-9 Catechol 1
-------------------------------
122-39-4 Diphenylamine 1
-------------------------------
123-42-2 Diacetone alcohol 1
-------------------------------
127-19-5 Dimethyl acetamide 1
-------------------------------
142-82-5 n-Heptane 1
-------------------------------
150-76-5 p-Methoxyphenol 1
-------------------------------
25013-15-4 Vinyl toluene 2
-------------------------------
34590-94-8 Dipropylene glycol 2
methyl ether
------------------------------------------------------------------------
(k) Effective date This section is effective on May 26, 2004.
[FR Doc. 04-9409 Filed 4-23-04; 8:45 am]
BILLING CODE 6560-50-S