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Proposed Rule2025-18431

Procedures for Chemical Risk Evaluation Under the Toxic Substances Control Act (TSCA)

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Published

September 23, 2025

Issuing agencies

Environmental Protection Agency

Abstract

The U.S. Environmental Protection Agency (EPA, "the Agency") is proposing to amend the procedural framework rule for conducting existing chemical risk evaluations under the Toxic Substances Control Act (TSCA). When conducting an existing chemical risk evaluation under TSCA, EPA must determine whether a chemical substance presents an unreasonable risk of injury to health or the environment, without consideration of costs or non-risk factors, including unreasonable risk to a potentially exposed or susceptible subpopulation identified as relevant to the risk evaluation, under the conditions of use. In this action, EPA proposes to rescind or revise certain 2024 amendments to the procedural framework rule to effectuate the best reading of the statute and ensure that the procedural framework rule does not impede the timely completion of risk evaluations or impair the effective and efficient protection of health and the environment.

Full Text

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<title>Federal Register, Volume 90 Issue 182 (Tuesday, September 23, 2025)</title>
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[Federal Register Volume 90, Number 182 (Tuesday, September 23, 2025)]
[Proposed Rules]
[Pages 45690-45717]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-18431]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 702

[EPA-HQ-OPPT-2025-0260; FRL-8529.1-01-OCSPP]
RIN 2070-AL27

Procedures for Chemical Risk Evaluation Under the Toxic
Substances Control Act (TSCA)

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The U.S. Environmental Protection Agency (EPA, ``the Agency'')
is proposing to amend the procedural framework rule for conducting
existing chemical risk evaluations under the Toxic Substances Control
Act (TSCA). When conducting an existing chemical risk evaluation under
TSCA, EPA must determine whether a chemical substance presents an
unreasonable risk of injury to health or the environment, without
consideration of costs or non-risk factors, including unreasonable risk
to a potentially exposed or susceptible subpopulation identified as
relevant to the risk evaluation, under the conditions of use. In this
action, EPA proposes to rescind or revise certain 2024 amendments to
the procedural framework rule to effectuate the best reading of the
statute and ensure that the procedural framework rule does not impede
the timely completion of risk evaluations or impair the effective and
efficient protection of health and the environment.

DATES: Comments must be received on or before November 7, 2025. Under
the Paperwork Reduction Act, comments on the information collection
provisions are best assured of consideration if the Office of
Management and Budget (OMB) receives a copy of your comments on or
before October 23, 2025.

ADDRESSES: Submit your comments, identified by docket identification
(ID) number EPA-HQ-OPPT-2025-0260, through the Federal eRulemaking
Portal at <a href="https://www.regulations.gov">https://www.regulations.gov</a>. Follow the online instructions
for submitting comments. Do not submit electronically any information
you consider to be Confidential Business Information (CBI) or other
information whose disclosure is restricted by statute. Additional
instructions on commenting or visiting the docket, along with more
information about dockets generally, is available at <a href="https://www.epa.gov/dockets">https://www.epa.gov/dockets</a>.

FOR FURTHER INFORMATION CONTACT:
For technical information contact: Kelly Summers, Existing
Chemicals Risk Management Division, Office of Pollution Prevention and
Toxics, Environmental Protection Agency, 1200 Pennsylvania Ave. NW,
Washington, DC 20460-0001; telephone number: (202) 564-2201; email
address: <a href="/cdn-cgi/l/email-protection#14404757554b5266757971637b667f4b46617871547164753a737b62"><span class="__cf_email__" data-cfemail="91c5c2d2d0ced7e3f0fcf4e6fee3facec3e4fdf4d1f4e1f0bff6fee7">[email&#160;protected]</span></a>.
For general information contact: The TSCA Assistance Information
Service Hotline, Goodwill of the Finger Lakes, 422 South Clinton Ave.,
Rochester, NY 14620; telephone number: (800) 471-7127 or (202) 554-
1404; email address: <a href="/cdn-cgi/l/email-protection#dd898e9e9cf095b2a9b1b4b3b89db8adbcf3bab2ab"><span class="__cf_email__" data-cfemail="7b2f28383a5633140f1712151e3b1e0b1a551c140d">[email&#160;protected]</span></a>.

SUPPLEMENTARY INFORMATION:

I. Executive Summary

A. Does this action apply to me?

EPA is proposing to amend procedural requirements that apply to the
Agency's activities in conducting risk evaluations under TSCA section
6(b) (15 U.S.C. 2605(b)). As part of this action, EPA is proposing
certain amendments to the process and requirements that manufacturers
(including importers) would be required to follow when requesting that
the Agency conduct a risk evaluation on a particular chemical
substance. You may be potentially affected by this action if you
manufacture or import chemical substances regulated under TSCA. Since
other entities may also be interested, the Agency has not attempted to
describe all the specific entities and corresponding North American
Industrial Classification System (NAICS) codes for entities that may be
interested in or affected by this action. The following list of NAICS
codes is not intended to be exhaustive, but rather provides a guide to
help readers determine whether this proposed action would apply to
them. Potentially affected entities may include:
<bullet> Petroleum Refineries (NAICS code 324110);
<bullet> Chemical Manufacturing (NAICS code 325);
<bullet> Unlaminated Plastics Film and Sheet (except Packaging)
Manufacturing (NAICS code 326113);
<bullet> Unlaminated Plastics Profile Shape Manufacturing (NAICS
code 326121);
<bullet> Plastics Pipe and Pipe Fitting Manufacturing (NAICS code
326122);
<bullet> Laminated Plastics Plate, Sheet (except Packaging), and
Shape Manufacturing (NAICS code 326130);
<bullet> Polystyrene Foam Product Manufacturing (NAICS code
326140);
<bullet> Urethane and Other Foam Product (except Polystyrene)
Manufacturing (NAICS code 326150);
<bullet> Plastics Bottle Manufacturing (NAICS code 326160);
<bullet> Plastics Plumbing Fixture Manufacturing (NAICS code
326191);
<bullet> All Other Plastics Product Manufacturing (NAICS code
326199);
<bullet> Tire Manufacturing (except Retreading) (NAICS code
326211);
<bullet> Tire Retreading (NAICS code 326212);
<bullet> Rubber and Plastics Hoses and Belting Manufacturing (NAICS
code 326220);
<bullet> Rubber Product Manufacturing for Mechanical Use (NAICS
code 326291);
<bullet> All Other Rubber Product Manufacturing (NAICS code
326299);
<bullet> Pottery, Ceramics, and Plumbing Fixture Manufacturing
(NAICS code 327110);
<bullet> Clay Building Material and Refractories Manufacturing
(NAICS code 327120);
<bullet> Flat Glass Manufacturing (NAICS code 327211);
<bullet> Other Pressed and Blown Glass and Glassware Manufacturing
(NAICS code 327212);
<bullet> Glass Container Manufacturing (NAICS code 327213);
<bullet> Glass Product Manufacturing Made of Purchased Glass (NAICS
code 327215);
<bullet> Cement Manufacturing (NAICS code 327310);
<bullet> Ready Mix Concrete Manufacturing (NAICS code 327320);
<bullet> Concrete Block and Brick Manufacturing (NAICS code
327331);
<bullet> Concrete Pipe Manufacturing (NAICS code 327332); and
<bullet> Other Concrete Product Manufacturing (NAICS code 327390).
If you have any questions regarding the applicability of this
proposed action to a particular entity, consult the technical
information contact listed under FOR FURTHER INFORMATION CONTACT.

B. What is the Agency's authority for this proposed action?

The statutory authority for this proposed action is TSCA section
6(b)(4)(B), which requires EPA to establish, by rule, a process to
conduct risk evaluations that meet applicable

[[Page 45691]]

statutory requirements (15 U.S.C. 2605(b)(4)(B)). As detailed in Units
II.A and II.B of this preamble, EPA originally promulgated the
procedural framework rule for risk evaluations under TSCA section
6(b)(4)(B) in 2017 and subsequently revised the procedural framework
rule in 2024. Unless provided otherwise by law, agencies may
reconsider, revise, or rescind prior rules by acknowledging the change,
offering a reasonable basis for the change, and taking any significant
reliance interests into account. See FDA v. Wages & White Lion Invs.,
L.L.C., 145 S. Ct. 898, 917 (2025); FCC v. Fox Television Stations,
Inc., 556 U.S. 502, 515 (2009); Motor Vehicle Mfrs. Ass'n v. State Farm
Mut. Auto. Ins. Co., 463 U.S. 29, 42 (1983). For the reasons set out in
Units II and III of this preamble, EPA is proposing to rescind or
revise many of the changes made through the 2024 amendments to
effectuate the best reading of the statute and address serious concerns
arising from Agency and stakeholder experience in application of the
amended procedural framework rule. EPA is not currently aware of any
significant reliance interests in the 2024 amendments to the procedural
framework rule at issue in this proposal, which remain fairly recent
and apply almost exclusively to internal Agency process. EPA seeks
comment on the changes proposed in this action, including on whether
stakeholders have any significant reliance interests on the 2024
amendments at issue and, if so, how such interests should be accounted
for in any final action.

C. What action is the Agency proposing to take?

EPA is proposing to amend the procedural framework rule that
governs how the Agency conducts risk evaluations on existing chemical
substances under TSCA section 6(b) (15 U.S.C. 2605(b)). These proposed
amendments are specifically targeted towards changes made in the 2024
final rule that may not be consistent with the best reading of TSCA and
that may impede the timely completion of risk evaluations and
unnecessarily impair the effective and efficient protection of health
and the environment. Provisions being reconsidered include whether TSCA
necessitates a single risk determination for each chemical substance
evaluated versus a risk determination for each condition of use of the
given chemical substance, outlined in Unit III.B; whether EPA must
evaluate all conditions of use and all exposure routes and pathways in
a risk evaluation, outlined in Unit III.A.3; whether and how the use of
personal protective equipment and engineering and administrative
controls in an occupational work environment should be considered,
outlined in Unit III.C.1; certain regulatory definitions and whether
regulatory definitions should be broader than the statutory
definitions, outlined in Unit III.D.2; and what process EPA should
follow when reconsidering aspects of a risk evaluation, outlined in
Unit III.E. EPA is also proposing certain amendments to the process and
requirements that manufacturers (including importers) would be required
to follow when they request an Agency-conducted TSCA risk evaluation on
a particular chemical substance, outlined in Unit III.F.
Specifically, EPA is proposing to amend the regulations at: 40 CFR
702.31 so that the changes to the procedures as part of this rulemaking
would be applied to all risk evaluations initiated on or after the date
of the final rule and would be applied to risk evaluations that are in
process as of the date of the final rule, but not yet finalized, to the
extent practicable; 40 CFR 702.33 to revise or add definitions to
ensure transparency and accountability in conducting risk evaluations;
40 CFR 702.37 and 40 CFR 702.39 to remove provisions in the 2024 final
rule that require EPA to consider every condition of use and every
exposure route and pathway based on reasonably available information
without exception when conducting a risk evaluation under TSCA section
6(b); 40 CFR 702.39, to return to the risk determination approach in
the 2017 final rule, which required EPA to make a determination of
unreasonable risk for each condition of use instead of a single risk
determination on the chemical substance as a whole, and to further
clarify how EPA will take occupational exposure controls into account
when conducting risk evaluations and making risk determinations; 40 CFR
702.43 to revise procedures established in the 2024 final rule for
whether and how EPA would endeavor to revise or supplement final scope
documents and draft or final risk evaluations; and 40 CFR 702.45 to
generally scale back the information collection obligations that the
2024 final rule imposed on requesting manufacturers, and to clarify
that manufacturers that withdraw a request before it is granted do not
incur fees.
There are certain aspects of the current risk evaluation procedural
regulations that EPA is not proposing to change, including the general
revised organization of the regulations as amended in the 2024 final
rule. EPA is not proposing to make edits to the definitions found in 40
CFR 702.33, some of which were changed in the 2024 final rule, except
for those specifically called out in this proposal (e.g., overburdened
communities). Further, EPA is not proposing to make changes to the
general requirements (40 CFR 702.37) and components of risk evaluations
(40 CFR 702.39), some of which were amended in the 2024 rule, except
where changes are outlined in this proposal (e.g., deletion of 40 CFR
702.39(8) and (9)).
For risk evaluations initiated prior the effective date of the
final rule, but not yet finalized, EPA will seek to apply the
requirements to the extent practicable. These requirements shall not
apply retroactively to risk evaluations already finalized.
EPA is requesting public comment on all aspects of this proposal.

D. Why is the Agency proposing this action?

As further explained in Units I, II, and III of this preamble, EPA
has reviewed the May 3, 2024, final rule entitled Procedures for
Chemical Risk Evaluation Under the Toxic Substances Control Act (89 FR
37028, May 3, 2024) (FRL-8529-02-OCSPP) (Ref. 1) (hereinafter ``2024
final rule''), which amended the July 20, 2017, final rule entitled
Procedures for Chemical Risk Evaluation Under the Amended Toxic
Substances Control Act (82 FR 33726, July 20, 2017) (FRL-9964-38) (Ref.
2) (hereinafter ``2017 final rule'') that established procedures and
requirements for chemical risk evaluation under TSCA, in consideration
of:
<bullet> The statutory text and structure and congressional intent;
<bullet> Executive Order 14219, ``Ensuring Lawful Governance and
Implementing the President's `Department of Government Efficiency'
Deregulatory Initiative,'' which directs agencies to initiate a process
to review existing rules for consistency with law and Administration
policy and to identify certain regulations for potential rescission or
modification (90 FR 10583, February 19, 2025) (Ref. 3); and
<bullet> Executive Order 14303, ``Restoring Gold Standard Science''
(90 FR 22601, May 23, 2025) (Ref. 4).
As a result of this review, the Agency is proposing targeted
amendments to the 2024 final rule and associated regulatory text.

E. What are the estimated incremental impacts of this action?

The incremental impacts of this action are associated with
revisions to

[[Page 45692]]

procedural requirements, as described in Unit III.F of this preamble,
that apply to manufacturers when manufacturers (including importers)
voluntarily request that EPA perform a risk evaluation on a particular
chemical substance. EPA has estimated the potential burden and costs
associated with the proposed requirements for submitting such a
request. These estimates of burden and costs are available in the
docket (Ref. 5), discussed in Unit VI of this preamble, and briefly
summarized here.
The total estimated annual burden is 166 hours and $91,831 (per
year), which is based on an estimated per request burden of 166 hours.
EPA's evaluation of the potential costs associated with this action
is discussed in Unit VI.C of this preamble. Because this proposed
action focuses on the activities that a manufacturer must perform in
voluntarily requesting a risk evaluation, the estimated incremental
costs to the public are expected to be negligible. However, there are
Paperwork Reduction Act (PRA) related burden and costs if industry
chooses to submit a manufacturer requested risk evaluation to the
Agency. This rulemaking is expected to reduce the regulatory burden
associated with these submissions resulting in an estimated PRA
activity cost savings of $23,880 per year (assuming one submission per
year) as compared to the 2024 final rule.
EPA specifically requests comment on the burden estimate and
assumptions associated with the calculation associated with the burden
(e.g., number of requests EPA expects). More generally, EPA requests
comment on whether and how the proposed rule would reduce burdens, and
welcomes detailed information, examples, and data addressing the
impacts of the rule.

F. What should I consider as I prepare my comments for EPA?

EPA is requesting public comment on all aspects of this proposal.
Throughout this proposed rule, the Agency is soliciting feedback from
the public on specific issues. See Unit IV for a summary of those
specific requests for comment.
1. Submitting CBI
Do not submit CBI to EPA through <a href="https://www.regulations.gov">https://www.regulations.gov</a> or
email. If you wish to include CBI in your comment, please follow the
applicable instructions at <a href="https://www.epa.gov/dockets/commenting-epa-dockets#rules">https://www.epa.gov/dockets/commenting-epa-dockets#rules</a> and clearly mark the part or all of the information that
you claim to be CBI. In addition to one complete version of the comment
that includes information claimed as CBI, a copy of the comment that
does not contain the information claimed as CBI must be submitted for
inclusion in the public docket. Information so marked will not be
disclosed except in accordance with procedures set forth in 40 CFR part
2.
2. Tips for Preparing Your Comments
When preparing and submitting your comments, see the commenting
tips at <a href="https://www.epa.gov/dockets/commenting-epa-dockets">https://www.epa.gov/dockets/commenting-epa-dockets</a>.

II. Background

TSCA section 6(b)(4)(B) requires EPA to establish, by rule, a
process to conduct risk evaluations that meet applicable statutory
requirements (15 U.S.C. 2605(b)(4)(B)). EPA originally promulgated the
procedural framework rule for risk evaluations under TSCA section
6(b)(4)(B) in 2017 and subsequently revised the procedural framework
rule in 2024. This Unit summarizes the background for this proposed
rule, including the 2017 final rule, judicial review of the 2017 final
rule, the 2024 final rule, and EPA's review of the 2024 final rule in
consideration of the Administration's priorities and recent judicial
decisions on statutory interpretation, including the Supreme Court's
decision in Loper Bright Enterprises v. Raimondo, 603 U.S. 369 (2024).

A. The 2017 Final Rule

As amended by the 2016 Frank R. Lautenberg Chemical Safety for the
21st Century Act (Pub. L. 114-182, 130 Stat. 448) (Lautenberg Act),
TSCA section 6(b)(4)(B) requires EPA to establish, by rule, a process
to conduct risk evaluations in accordance with statutory requirements
(15 U.S.C. 2605(b)(4)(B)). Specifically, Congress directed EPA to use
this process to ``determine whether a chemical substance presents an
unreasonable risk of injury to health or the environment, without
consideration of costs or other non-risk factors, including an
unreasonable risk to a potentially exposed or susceptible subpopulation
identified as relevant to the risk evaluation by the Administrator,
under the conditions of use'' (15 U.S.C. 2605(b)(4)(A)). TSCA sections
6(b)(4)(A) through (H) enumerate the deadlines and minimum requirements
applicable to this process, including provisions that direct which
chemical substances must undergo risk evaluation, the development of
criteria for manufacturer-requested risk evaluations, the minimum
components of an Agency risk evaluation, and the timelines for public
comment and completion of the risk evaluation (15 U.S.C. 2605(b)(4)(A)
through (H)). The statute also requires EPA to consider reasonably
available information and operate in a manner that is consistent with
the best available science and make decisions based on the weight of
the scientific evidence (15 U.S.C. 2625(h), (i), (k)).
Accordingly, on July 20, 2017, EPA promulgated a final rule that
established the process for conducting risk evaluations under TSCA
section 6(b). The 2017 final rule identified the components of the risk
evaluation process applicable to a chemical substance or category of
chemical substances including: scope, hazard assessment, exposure
assessment, risk characterization, and finally a risk determination.
For the unreasonable risk determination, the 2017 final rule at 40 CFR
702.47 stated that ``EPA will determine whether the chemical substance
presents an unreasonable risk of injury to health or the environment
under each condition of uses [sic] within the scope of the risk
evaluation.'' This process was intended to be used for the initial ten
chemicals identified for evaluation, for chemical substances designated
as high-priority substances during the prioritization process under
TSCA section 6(b)(1), and for those chemical substances for which EPA
has initiated a risk evaluation in response to a manufacturer request.
While the regulatory text of the 2017 final rule did not directly
address the risk evaluation scope decisions that EPA might make, EPA
explained in the preamble that it interpreted the requirements of TSCA
section 6 to apply to conditions of use for which manufacturing,
processing, or distribution in commerce is intended, known to be
occurring, or reasonably foreseen to occur, rather than to legacy uses,
which EPA used as a term for continuing, in-situ uses of chemicals for
which manufacturing, processing, or distribution in commerce had ceased
(e.g., certain phased-out flame retardants present in textiles or
furniture that continue to be used, asbestos-containing pipe wrap,
etc.), associated disposal (disposal of legacy uses), or legacy
disposals (disposals that had already occurred). Therefore, EPA
provided that it would not include legacy uses, associated disposals,
or legacy disposals of a chemical in the scope of a risk evaluation on
that chemical. The 2017 final rule also included various other
provisions, such as requirements for the form and content of
manufacturer requests for risk evaluations, a provision indicating that
manufacturer-submitted information would be held to the scientific

[[Page 45693]]

standards in TSCA section 26(h), and a provision establishing that the
submission of inaccurate, incomplete, or misleading information
pursuant to a manufacturer-requested risk evaluation is a prohibited
act subject to penalties under Title 18 of the U.S. Code.

B. Judicial Review of the 2017 Final Rule

Several non-governmental organizations filed petitions for judicial
review of the 2017 final rule, which were consolidated in the U.S.
Court of Appeals for the Ninth Circuit as Safer Chemicals, Healthy
Families v. EPA on August 10, 2017 (Ref. 6). The Ninth Circuit issued a
decision on November 14, 2019, holding that EPA's exclusion of ``legacy
uses and associated disposals'' from the conditions of use that the
Agency would consider in any risk evaluation was not consistent with
the law in that the TSCA definition for condition of use clearly
includes uses and future disposals. 943 F.3d 397, 425 (9th Cir. 2019)
(Ref. 6). At EPA's request, the Ninth Circuit concurrently (1) vacated
and remanded the rule provisions applying criminal penalties to the
submission of inaccurate or incomplete information to EPA pursuant to a
manufacturer-requested risk evaluation, and (2) remanded without
vacatur the rule provisions addressing the information requirements
for, and application of the TSCA section 26 scientific standards to, a
manufacturer-requested risk evaluation. Safer Chems., Healthy Families
v. EPA, 791 F. App'x 653, 656 through 657 (9th Cir. 2019) (Ref. 7).
The Court declined to rule on several other challenges raised by
the petitioners, including the argument that the 2017 final rule
improperly required EPA to make risk determinations for each condition
of use rather than a single risk determination for the chemical
substance and the argument that the 2017 final rule improperly granted
EPA the discretion to exclude certain conditions of use from the scope
of a risk evaluation. The Court reasoned that petitioners' arguments
were not justiciable because it was unclear ``whether the Agency will
actually conduct risk evaluations in the manner [those litigants]
fear[ed].'' Safer Chems., 943 F.3d at 413. (Ref. 6). With regard to
petitioners' claim that EPA intended to exclude conditions of use out
of the scope of the risk evaluations, the court held that claim not
ripe and did ``not interpret the language in the [2017 final rule] to
say anything about exclusion of conditions of use.'' Id. at 420 (Ref.
6).

C. The 2024 Revisions to the 2017 Final Rule

After a change in Administration, President Biden issued Executive
Order 13990 on January 20, 2021 (86 FR 7037, January 25, 2021) (Ref. 8)
which instructed agencies to review and consider revising regulations
finalized by the prior Administration according to a new set of
environmental policies. In response to the Executive Order, EPA
announced certain policy changes for TSCA risk evaluations on June 30,
2021, including expanded consideration of exposure pathways,
constraints on EPA's assumptions regarding personal protective
equipment (``PPE'') use, and making risk determinations on the ``whole
chemical,'' rather than on individual conditions of use (Ref. 9).
In consideration of Executive Order 13990, EPA issued a Notice of
Proposed Rulemaking on October 30, 2023 (Procedures for Chemical Risk
Evaluation Under the Toxic Substances Control Act (TSCA), 88 FR 74292,
October 30, 2023 (FRL-8529-01-02-OCSPP)) (hereinafter ``2023 proposed
rule'') (Ref. 10), that included the policy changes identified in 2021,
the changes EPA determined necessary to make the rule consistent with
the Ninth Circuit's decision in Safer Chemicals, and a number of other
proposed revisions. During a 45-day public comment period, public
commenters raised a multitude of issues, including but not limited to
concerns about the proposed expanded consideration of exposure
pathways, proposed constraints on EPA's assumptions regarding personal
protective equipment (``PPE'') use, and EPA's proposal to make risk
determinations on the ``whole chemical,'' rather than on individual
conditions of use as detailed in EPA's Response to Comment Document on
the 2023 proposed rule (Ref. 11). EPA issued the 2024 final rule on May
3, 2024 (89 FR 37028) (FRL-8529-02-OCSPP) (Ref. 1). Provisions of the
2024 final rule being reconsidered in this proposed action are
described in this Unit and in Unit III.
The 2024 final rule codifies provisions requiring EPA to consider
all exposure pathways, including those covered by other statutes such
as the Clean Air Act and the Clean Water Act, and to include all
reasonably known conditions of use within the scope of the risk
evaluation, based on an interpretation of TSCA section 6(b)(4) that
limits EPA's discretion on scoping of risk evaluations. Likewise, the
2024 final rule interprets TSCA section 6(b)(4)(A) to require that EPA
make a single determination of unreasonable risk for the entire
chemical substance rather than a risk determination for each individual
condition of use assessed. The 2024 final rule also requires EPA to
consider ``reasonably available information, including known and
reasonably foreseen circumstances where subpopulations of workers are
exposed due to ineffective use of personal protective equipment,'' and
that the Agency ``not consider exposure reduction based on assumed use
of personal protective equipment as part of the risk determination'' 40
CFR 702.39(f)(2). This regulatory language is based in part on the
possibility of noncompliance with Occupational Safety and Health
Administration (OSHA) standards, purported gaps or limitations in OSHA
coverage, and lessons learned from the Agency's implementation of the
risk evaluation program to date (89 FR 37028, May 3, 2024) (FRL-8529-
02-OCSPP) (Ref. 1, at p. 37037).
The 2024 final rule also amended requirements for manufacturer-
requested risk evaluations for the stated reason of assisting EPA in
identifying conditions of use and collecting hazard and exposure
information for the requested chemical substances. Under the 2024 final
rule, manufacturers requesting risk evaluations bear the burden of
providing EPA with all of the information necessary to conduct the risk
evaluation. The revisions require manufacturers to gather and provide
all such information that is known to, or reasonably ascertainable by
them. The 2024 final rule explains that manufacturers must exercise due
diligence in collecting this information, which includes a thorough
search of publicly available information, an inquiry throughout the
manufacturer's entire organization, and inquiries to upstream
suppliers, downstream users, and employees and other agents of the
manufacturer. The 2024 final rule, at 40 CFR 702.45(a)(4), generally
holds manufacturer-requested risk evaluations to the same information
standards as EPA-initiated risk evaluations, which would preclude
limited risk evaluations on a subset of the conditions of use of
interest to the requesting manufacturers.
Other revisions related to the 2021 policy changes included the
addition of the phrase ``overburdened communities'' to the definition
of the term ``potentially exposed or susceptible populations''; the
definition in the 2017 final rule had simply repeated the definition in
the statute. In addition, the preamble to the 2024 final rule discussed
EPA's intention to adhere to the Ninth Circuit's decision in Safer
Chemicals, 943 F.3d 397 (Ref. 6), and to

[[Page 45694]]

include legacy uses and associated disposals in a ``part 2'' risk
evaluation for asbestos, as well as in future risk evaluations.
Provisions of the 2024 final rule not directly related to the 2021
policy change announcement included language on the process EPA will
follow to revise risk evaluation scope documents and other risk
evaluation documents. These include final risk evaluations, which would
generally require EPA to reinitiate the prioritization process under 40
CFR 702.7 for the chemical substance, unless EPA determines that it is
in the interest of protecting human health or the environment to
proceed immediately with substantively revising the risk evaluation.
The 2024 final rule also committed EPA to either performing an
aggregate exposure assessment in each risk evaluation or explaining why
it had not done so.
With respect to regulatory definitions, the 2024 final rule removed
the definitions of ``best available science'' and ``weight of the
scientific evidence,'' and incorporated the statutory considerations
related to the term ``best available science'' elsewhere in the
regulation. Minor amendments to the definitions of the terms
``pathways,'' ``routes,'' ``aggregate exposure,'' and ``sentinel
exposure'' were made to align with Agency phraseology and guidance, and
to clarify that aggregate and sentinel exposures can apply to
individuals and communities. The 2024 final rule also included
additional clarifications and a reorganization of the sections in 40
CFR part 702, subpart B. More information on these amendments can be
found in the preamble to the 2024 final rule.
Petitions for review of the 2024 final rule were filed by industry
stakeholders, a union, and environmental advocacy organizations. See
United Steel, et al. v. EPA, No. 24-1151 (D.C. Cir.). The litigation
was consolidated in the U.S. Court of Appeals for the D.C. Circuit
Court and is currently in abeyance while EPA reconsiders the 2024 final
rule.

D. Review of the 2024 Final Rule

Following another change in Administration, President Trump revoked
E.O. 13990 on January 20, 2025 (90 FR 8353) (Ref. 12) and issued
Executive Order 14219 on February 19, 2025, which directs agency heads
to review all regulations under their jurisdiction for consistency with
law and Administration policy and identify inconsistent regulations for
recission or modification (90 FR 10583) (Ref. 3). Among the categories
of regulations to be identified are those that are based on anything
other than the best reading of the underlying statutory authority;
those that significantly and unjustifiably impede technological
innovation, infrastructure development, disaster response, inflation
reduction, research and development, economic development, energy
production, land use, and foreign policy objectives; and those that
impose undue burdens on small business and impede private enterprise
and entrepreneurship.
On March 10, 2025, Administrator Zeldin identified the 2024 final
rule as one such regulation under review and announced that EPA would
be conducting a rulemaking to review multiple aspects of the 2024 final
rule for consistency with law and Administration policy (Ref. 13). The
Administrator also described the importance of the activity under TSCA
to review chemicals already in commerce, supporting his initiative for
clean air, land and water for every American, as well as advancing
permitting reform, cooperative federalism and cross-agency partnerships
by better integrating the best workplace standards from across the
Federal government and industry and meeting TSCA's tight timelines for
risk evaluations. Specific aspects of the 2024 final rule mentioned in
the Administrator's March 10, 2025, press release include whether EPA
must evaluate all of the conditions of use of a chemical substance, the
single risk determination requirement, whether and how the use of PPE
and industrial controls in an occupational work environment should be
incorporated into risk evaluations, and whether terms should be more
broadly defined in the regulation than they are in the statute (Ref.
13).
Soon after the 2024 final rule was published, the Supreme Court
issued its decision in Loper Bright. In that case, the Court held that
when interpreting statutes administered by federal agencies, courts
must abandon the two-step framework in Chevron, U.S.A., Inc. v. NRDC,
Inc., 467 U.S. 837, 842 through 843 (1984), and instead use ordinary
tools of statutory interpretation to identify and apply the single best
reading of the statute at issue. Loper Bright, 603 U.S. 369 at 400. EPA
believes that certain provisions of the 2024 final rule are not based
on the best reading of TSCA and are thus impermissible under the
Court's decision in Loper Bright.
In addition, as discussed in more detail in Unit III of this
preamble, EPA's preliminary review of the 2024 final rule found that
certain aspects of the rule, such as the requirement to evaluate all
conditions of use and all exposure routes and pathways in a risk
evaluation, could negatively impact EPA's ability to complete risk
evaluations in a timely manner. EPA also found that other aspects of
the rule, such as the single risk determination requirement, could
negatively impact technological innovation, small business, and private
enterprise and entrepreneurship.
Thus, this proposal reflects the results of EPA's targeted review
of these aspects of the 2024 final rule and selected other provisions
as described in Unit III of this preamble. EPA is not proposing to
amend provisions included in the 2024 final rule that are not outlined
in Unit III, and requests comment whether it should revisit other
aspects of the 2024 final rule. This proposal is also deregulatory in
nature, in that it would reduce the regulatory burden associated with
the information a manufacturer would have to provide with a
manufacturer-requested risk evaluation.

III. Proposed Amendments

A. Scope of TSCA Risk Evaluations

1. Introduction
EPA is proposing to remove provisions in the 2024 final rule that
require EPA to consider each and every condition of use and each and
every exposure route and pathway based on reasonably available
information when conducting a risk evaluation under TSCA section 6(b).
Specifically, EPA is proposing to remove the phrase ``EPA will not
exclude conditions of use from the scope of the risk evaluation'' from
40 CFR 702.37(a)(4), combine the remaining text with subparagraph
(a)(3), and remove 40 CFR 702.39(d)(9) in its entirety. The Lautenberg
Act (Pub. L. 114-182, 130 Stat. 448) amended TSCA to direct EPA to
conduct comprehensive risk evaluations, a more efficient process for
EPA to evaluate the large number of existing chemical substances than
the piecemeal approach that EPA had taken previously in several cases,
but also provided EPA with some discretion regarding which conditions
of use, exposure routes, and exposure pathways it will consider in risk
evaluation (Ref. 14 at p. 3519).
When TSCA was originally signed into law in 1976, there were tens
of thousands of chemicals in commerce and, while the law gave EPA
authority to conduct assessments to determine whether those existing
chemicals present unreasonable risk of injury to health or the
environment, TSCA did not specifically require that EPA do so (88 FR
74292, October 30, 2023) (Ref. 10 at p. 74296). EPA did conduct risk

[[Page 45695]]

assessments on a handful of these existing chemicals prior to 2016, but
most of those assessments were focused on a specific subset of chemical
uses (e.g., paint and coating removal, vapor degreasing) being
evaluated at the time. This approach to assessing existing chemicals,
taken under the original TSCA, along with other aspects of the TSCA
authorities regarding existing chemicals, failed to inspire public
confidence in the safety of chemicals present in our households,
communities, and the environment (88 FR 74292, October 30, 2023) (Ref.
10 at p. 74296).
The 2016 amendments to TSCA were designed to address this lack of
confidence. One of the defining features of the amendments was the
mandate for EPA to methodically prioritize those thousands of existing
chemicals for review, and then to evaluate their risks under the
chemical's ``conditions of use,'' i.e., ``the circumstances, as
determined by the Administrator, under which a chemical substance is
intended, known, or reasonably foreseen to be manufactured, processed,
distributed in commerce, used, or disposed of'' (15 U.S.C. 2602(4)).
While clearly a significant undertaking, Congress recognized that
meaningful progress on evaluating the universe of thousands of existing
chemicals would necessitate such a mandate, along with deadlines for
completing the work (Ref. 14). A continuation of the pre-2016 approach
to risk evaluation and risk management for this universe of chemicals
would be inefficient and would further delay progress in the overall
undertaking.
Completing these comprehensive risk evaluations within the
timeframes set forth by Congress, only 3 to 3.5 years, represents a
significant ongoing challenge for EPA. EPA believes that risk
evaluations under TSCA cannot be so complex or procedurally cumbersome
that they cannot reliably be completed within the statutory timeframes.
At the same time, EPA also believes it should not routinely produce
partial or incomplete TSCA risk evaluations. In order for TSCA
implementation efforts to be sustainable while also meeting the
statutory timeframes for completing evaluations, EPA believes risk
evaluations must be fit-for-purpose such that the Agency meets both the
substantive statutory and regulatory requirements for conducting risk
evaluations, while completing those evaluations within the statutory
deadlines. Further, the statute provides EPA with discretion as to the
``hazards, exposures, conditions of use, and the potentially exposed or
susceptible subpopulations the Administrator expects to consider'' in a
risk evaluation under TSCA (15 U.S.C. 2065(b)(4)(D)) as well as on the
level of evaluation expected for each aspect of the risk evaluation.
EPA believes that risk evaluation scoping decisions are highly
fact-specific and are made on a case-by-case basis. EPA intends to
generally explain its scoping decisions in the draft scope document or
the draft risk evaluation, as appropriate. EPA intends to continue to
release draft scope documents and draft risk evaluations for public
comment, to provide multiple opportunities for stakeholders to review
scoping decisions. In addition, TSCA section 19 provides for judicial
review of such decisions, which must be based on substantial evidence
in the rulemaking record taken as a whole (15 U.S.C. 2618).
2. Conditions of Use
EPA proposes that there are two different types of discretion
involved in considering the scope of a risk evaluation with regard to
conditions of use. First, early in the TSCA section 6(b) process, EPA
must determine what the conditions of use are for a candidate chemical
substance. That is, ``the circumstances, as determined by the
Administrator, under which a chemical substance is intended, known, or
reasonably foreseen to be manufactured, processed, distributed in
commerce, used, or disposed of'' (15 U.S.C. 2602(4)). The decision as
to whether a circumstance is ``intended, known, or reasonably
foreseen'' to occur necessarily involves the exercise of discretion,
particularly as to whether an intention to take an action exists, or
whether an occurrence is reasonably foreseeable. Second, once a
particular circumstance is determined to be a condition of use, EPA has
discretion to exclude it from the scope of the risk evaluation under
TSCA section 6(b)(4)(D) (15 U.S.C. 2605(b)(4)(D)). The question whether
the Agency has discretion under TSCA to exclude that condition of use
from the scope of a risk evaluation has been the source of much
discussion publicly, particularly during the development of the 2017
and 2024 final rules. While EPA agrees with the goal of the TSCA
amendments to establish a systematic approach to reviewing and
addressing potential risks posed by chemicals already in commerce, it
also believes that eliminating the Administrator's discretion to
determine which conditions of use are included in the risk evaluation
is neither mandated by the statute nor workable, given the magnitude of
the task.
In the 2017 final rule EPA expressed that it had discretionary
scoping authority (82 FR 33726, July 20, 2017) (Ref. 2 at p. 33729). In
support of this assertion of discretionary scoping authority in the
2017 final rule, EPA pointed to language in TSCA section 6(b)(4)(D)
that requires the Agency to identify the conditions of use in a scope
document that the Agency ``expects to consider'' in a risk evaluation
and the ``as determined by the Administrator'' phrasing in the
statutory definition of ``conditions of use'' itself (id. at 33729).
EPA argued that such language gave the Agency discretion to select
among the conditions of use and, ultimately, to exclude conditions of
use from the scope of TSCA risk evaluations. EPA expressed at that time
that those provisions empowered the Agency to exclude, for example,
conditions of use that the Agency deemed ``de minimis'' in nature, or
conditions of use where opportunities for exposure were likely to be
limited (e.g., closed system or intermediate) (id. at 33729). The 2017
final rule cited excerpts from the Senate's discussion of the House/
Senate Conference Report in support of EPA's contention that EPA had
some discretion to determine the scope of risk evaluations (id. at
33728). As described by Senator Vitter, one of the Senate Sponsors of
the legislation, this discretion ``assures that the Agency's focus on
priority chemicals is on conditions of use that raise the greatest
potential for risk. This also assures that the Agency can effectively
assess and control priority chemicals and meet the new law's strict
deadlines'' (Ref. 14 at p. 3519). For purposes of this proposed action,
EPA agrees with this statement on the focus and goals of TSCA section
6(b) risk evaluations. In exercising the scoping discretion proposed in
this action, EPA would not generally intend to exclude circumstances
that the reasonably available information indicates would raise the
greatest potential for risk.
EPA further proposes that experience in conducting risk evaluations
under TSCA section 6(b) has made clear that at least some discretion to
tailor the scope of risk evaluations is necessary to accomplish the
objective of making meaningful progress in comprehensively evaluating
the risks presented by existing chemicals while also complying with
TSCA's ambitious statutory deadlines. As mentioned in the 2017 final
rule, excluding de minimis uses and uses with minimal exposure
potential are two examples of how EPA might choose to focus risk
evaluations.

[[Page 45696]]

Byproducts are another example. The regulatory definition of
``manufacture for commercial purposes'' includes chemical substances
that are produced coincidentally during the manufacture, processing,
use, or disposal of another chemical substance or mixture, including
both byproducts that are separated from that other substance or mixture
and impurities that remain in that chemical substance or mixture. Such
byproducts and impurities may, or may not, in themselves have
commercial value (e.g., 40 CFR 704.3, 40 CFR 720.3). As explained in
the 2017 final rule, in some instances, it may be most appropriate from
a technical and policy perspective to evaluate the potential risks
arising from a chemical impurity within the scope of the risk
evaluation for the impurity itself. In other cases, it may be more
appropriate to evaluate such risks within the scope of the risk
evaluation for the separate chemical substances that bear the impurity
(82 FR 33726, July 20, 2017) (Ref. 2 at p. 33729). EPA believes that
this is generally the better approach for most chemical substances,
because the risks of the parent chemical and its byproducts will be
evaluated and managed together. In contrast, for example, although EPA
set out to conduct the risk evaluation for 1,4-dioxane by excluding
byproducts, stating that EPA would consider unintentional 1,4-dioxane
production in the risk evaluations of its various parent chemicals
(Ref. 15), EPA has since decided that the risks of 1,4-dioxane
production as a byproduct are best assessed in the same risk evaluation
as the other conditions of use of 1,4-dioxane (Refs. 15 and 16). In the
case of 1,4-dioxane, the parent chemicals are a diverse group, many of
which are not considered hazardous, including surfactants that have
appeared on EPA's Safer Chemical Ingredients List, which represents a
list of chemical ingredients EPA has evaluated and determined to be
safer than traditional chemical ingredients (Ref. 17). This discretion
to decide where to evaluate risks from byproducts, whether in the risk
evaluation for the chemical substance itself or in the risk evaluation
for the parent chemical, is necessary for this ambitious program to
work as intended.
Although EPA asserted in the 2024 final rule that it has no
discretion to exclude conditions of use from the scope of a risk
evaluation, the preamble also acknowledged that the Agency retains the
authority to exercise judgment in making its determination as to
whether a particular circumstance is intended, known, or reasonably
foreseen, and therefore falls within the definition of ``condition of
use'' for a particular chemical (89 FR 37028, May 3, 2024) (Ref. 1 at
pp. 37032 through 37033). EPA further explained in the 2024 final rule
that the Agency has and will continue to undergo a process to determine
each chemical's conditions of use, analyzing reasonably available
information and applying the facts, Agency expertise and professional
judgment on a case-by-case basis. The 2024 final rule states that, when
information suggests that a circumstance of manufacture, processing,
distribution in commerce, use or disposal is known to be occurring, or
is reasonably foreseen to occur in the future, EPA will determine that
circumstance to be a condition of use and include it within the scope
of the risk evaluation.
EPA's approach in the 2024 final rule to determining both the
conditions of use for a chemical substance and the scope of the risk
evaluation for the substance effectively eliminates the Agency's
discretion in scoping in favor of using the ``intended, known, or
reasonably foreseen'' language from the statutory definition of the
term ``conditions of use'' to achieve an appropriately-scoped risk
evaluation. Pursuant to the Supreme Court's decision in Loper Bright
EPA believes that TSCA is best read as permitting the Agency to
exercise discretion under TSCA section 3(4) in determining what
constitutes a condition of use, as well as discretion under TSCA
section 6(b)(4)(D) in determining what conditions of use EPA expects to
consider in a risk evaluation, recognizing that the statute clearly
envisions comprehensive risk evaluations. EPA continues to believe that
TSCA section 3(4) provides the Agency with discretion to determine
whether a use falls under the two buckets: (1) known, intended, or
reasonably foreseen, and (2) manufactured, processed, distributed in
commerce, used, or disposed of. Under the interpretation proposed in
this action, if EPA determines that a use falls into each of these
buckets, the Agency would conclude that the use is a condition of use.
Next, the Agency would determine in its discretion under TSCA section
6(b)(4)(d) whether EPA ``expects to consider'' the given condition of
use in the risk evaluation. This reading avoids the need to stretch the
Agency's discretion in TSCA section 3(4) in order to exclude certain
uses of a chemical, such as the unintentional byproduct example above,
while still maintaining EPA's ability to ensure an appropriately scoped
risk evaluation.
In the preamble to the 2023 proposed rule, EPA also discussed the
Ninth Circuit's Safer Chemicals decision on legacy use, associated
disposal, and legacy disposal (88 FR 74292, October 30, 2023) (FRL-
8529-01-OCSPP) (quoting Safer Chems., 943 F.3d at 425 through 426)
(Ref. 10 at p. 74298). As the Agency explained at the time, the 2017
final rule identified legacy disposal as falling outside the statutory
definition of ``conditions of use'' because EPA interpreted the
definition as focusing on circumstances that are prospective or on-
going, rather than reaching back to evaluate risks associated with
``legacy disposal'' (i.e., disposal that has already occurred). The
Ninth Circuit agreed that ``legacy disposal'' falls outside the
statutory definition of conditions of use, reasoning that a substance
that has already been disposed of will not ordinarily be intended,
known, or reasonably foreseen to be used again (Safer Chems., 943 F.3d
at 425 through 427) (Ref. 6). However, the court additionally held that
EPA could not categorically exclude legacy uses and associated
disposals from the definition of ``conditions of use'' because they
represent future use and disposals that do clearly fall within the
statutory definition of condition of use (id. at 424 through 425) (Ref.
6). The court reasoned that to the extent that these are prospective
use and disposal of a chemical substance that are intended, known, or
reasonably foreseen, they ``unambiguously fall within TSCA's definition
of `condition of use,''' regardless of whether there is ongoing
upstream manufacture, processing, or distribution in commerce (id. at
424 through 425). According to the 2017 final rule, a legacy use is the
continued use of a product, such as in-place asbestos insulation, after
manufacturing has ceased, and an associated disposal is the disposal of
a legacy use product (82 FR 33726, July 20, 2017) (Ref. 2 at p. 33729).
As explained in the preamble to the 2024 final rule, EPA has
committed to complying with the Safer Chemicals decision and continues
to exclude legacy disposals, but not legacy uses or associated
disposals, from the statutory definition of ``conditions of use.'' (89
FR 37028, May 3, 2024) (Ref. 1 at 37032). EPA includes this information
as background and does not propose to revisit or revise its position on
the matter.
EPA is proposing to delete the phrase ``EPA will not exclude
conditions of use from the scope of the risk evaluation''

[[Page 45697]]

from 40 CFR 702.37(a)(4) and combine, ``a fit-for-purpose approach may
result in varying types and levels of analysis and supporting
information for certain conditions of use, consistent with paragraph
(b) of this section. The extent to which EPA will refine its
evaluations for one or more condition of use in any risk evaluation
will vary as necessary to determine whether a chemical substance
presents an unreasonable risk of injury to health or the environment,''
with 40 CFR 702.37(a)(3). The revised subparagraph (a)(3) would read as
follows:

EPA will ensure that all supporting analyses and components of
the risk evaluation are suitable for their intended purpose, and
tailored to the problems and decision at hand, in order to inform
the development of technically sound determinations as to whether
each condition of use presents an unreasonable risk of injury to
health or the environment, based on the weight of the scientific
evidence. A fit-for-purpose approach may result in varying types and
levels of analysis and supporting information for certain conditions
of use, consistent with paragraph (b) of this section. The extent to
which EPA will refine its evaluations for one or more conditions of
use in any risk evaluation will vary as necessary to determine
whether the chemical substance presents an unreasonable risk of
injury to health or the environment under that condition of use.

As discussed in this Unit, EPA agrees that the amended TSCA requires
the Agency to conduct comprehensive risk evaluations, not multiple risk
evaluations for the same chemical, a handful of conditions of use at a
time. However, without the ability to decide where unintentional
byproduct manufacture will be evaluated, for example, or whether an
activity need not be assessed because it is unlikely to result in
exposures to a chemical substance, EPA will be unable to focus its risk
evaluations on the conditions of use that have the greatest potential
for risk and thereby effectively evaluate and manage risks while also
meeting the statutory deadlines.

EPA requests comment on all aspects of its proposed amendments to
40 CFR 702.37(a)(3) and (4), including whether the revisions are
sufficiently clear as to EPA's intent regarding appropriately scoped,
fit-for-purpose risk evaluations under TSCA section 6(b). Based on
additional information submitted to EPA, the Agency also considered
alternative provisions regarding the scope of TSCA risk evaluations
that the Agency is not proposing to include in this action but is
instead requesting comment on. Specifically, EPA requests comment on
whether a definition of ``reasonably foreseen'' would enhance the
transparency and predictability of EPA's decisions on the circumstances
of manufacture, processing, distribution in commerce, use, or disposal
that constitute conditions of use. EPA would likely draw a definition
from the considerations outlined by EPA's new chemicals program under
section 5 of TSCA (Ref. 18, at footnote 1). EPA also requests comment
on whether this rule should provide more specific considerations that
EPA will use in determining which conditions of use are within the
scope of the risk evaluation. Such considerations could include whether
there is a reasonable potential for exposure to humans or the
environment as a result of the condition of use, the extent to which
the potential risks posed by a chemical impurity can be addressed in a
risk evaluation for the separate chemical substance that bears the
impurity, and the extent to which risk reduction opportunities are
available for the condition of use. EPA requests comment on whether one
of these considerations should be whether the substance is present at a
de minimis level under the condition of use, and, if so, whether EPA
should promulgate a definition of de minimis, recognizing that the
toxicity of chemical substances vary. Finally, EPA is also interested
in comments on how to address conditions of use that are identified
after the conclusion of a risk evaluation on a chemical substance. As
previously stated, EPA does not believe stakeholders have reliance
interests pertaining to the process for future, yet-to-be-completed
risk evaluations that will be carried out in accordance with this
proposed rule, but seeks comments on any reliance interests commenters
believe they have.
3. Inclusion of All Exposure Pathways
In carrying out the first ten risk evaluations under TSCA, EPA
appropriately scoped those evaluations by excluding analysis of certain
exposures to the general population from releases to air, water, and
land. The approach, which was not contemplated in the 2017 rule but was
first articulated in ``Problem Formulation'' documents published in
2018 (after the Final Scope documents) for each of the first ten
chemicals undergoing risk evaluation, premised on an argument that
those pathways were already adequately assessed and managed--or could
be adequately assessed and managed--under other EPA statutes and
regulatory programs (Ref. 19 and 20). EPA further stated at that time
that its intention was to use Agency resources efficiently under the
TSCA program, avoid duplicating efforts taken pursuant to other Agency
programs, maximize scientific and analytical efforts, and meet TSCA's
statutory deadlines for completing risk evaluations. In the final risk
evaluations for the first ten chemicals, EPA excluded exposure pathways
that could be covered by regulatory programs under the Clean Air Act
(CAA), Clean Water Act (CWA), Safe Drinking Water Act (SDWA), Resource
Conservation and Recovery Act (RCRA), and Comprehensive Environmental
Response, Compensation, and Liability Act (CERCLA) (e.g., drinking
water pathways covered under the SDWA due to the existence of National
Primary Drinking Water Regulations (NPDWRs) with chemical-specific,
enforceable Maximum Contaminant Levels (MCL), or the inclusion of the
chemical as an unregulated chemical on the Candidate Contaminant List
(CCL)). EPA further asserted that this approach was supported by
several TSCA authorities, including TSCA section 6(b)(4)(D), which in
part directs the Agency to identify, in the scope document, the
exposures that the Administrator ``expects to consider'' in the
applicable risk evaluation, and TSCA section 9(b)(1), which allows the
Administrator to use other EPA administered statutes to address risks
to health or the environment, if the Administrator determines that
these risks ``could be eliminated or reduced to a sufficient extent''
by actions taken under other EPA administered statutes (Ref. 15).
This approach was criticized by EPA's Science Advisory Committee on
Chemicals (SACC) and several public commenters in comments on
individual risk evaluation documents (Refs. 22, 23, and 24). In
response to this and other external criticisms, EPA announced in June
of 2021 that it would abandon this approach and subsequently developed
the Draft TSCA Screening Level Approach for Assessing Ambient Air and
Water Exposures to Fenceline Communities Version 1.0 (Ref. 25). EPA
used this screening level approach during development of risk
management actions under TSCA section 6(a) to consider whether the
conditions of use assessed in six of the first ten risk evaluations may
have resulted in potential risks for nearby communities.
Further, EPA has consistently excluded from the scope of risk
evaluations certain exposures that are associated with a condition of
use, such as accidents, spills, leaks, and extreme weather-related
events like hurricanes and wildfires (89 FR 37028) (Ref. 1 at p.
37033); (82 FR 33726) (Ref. 2 at p. 33729). Therefore, EPA has
consistently read TSCA to provide EPA with some

[[Page 45698]]

discretion to exclude exposures. In the 2023 proposed amendments to the
procedural framework rule, EPA indicated that if accidents, spills,
leaks, or extreme weather-related events result in regular and
predictable changes in exposures associated with a given condition of
use of a chemical substance, such exposures would be known or
reasonably foreseen and would be considered within the scope of the
risk evaluation (88 FR 74292, October 30, 2023) (Ref. 10 at p. 74298).
In the 2024 final rule, EPA added that it would consider whether
exposures from accidents, spills, leaks, and weather-related events
``would be regular or predictable, versus those that are
unsubstantiated, speculative or otherwise not likely to occur'' (89 FR
37028, May 3, 2024) (Ref. 1 at p. 37033). Regardless, whether exposures
associated with such events might be reasonably foreseeable, EPA has
determined that, in the absence of reasonably available information
that shows that they are regular and predictable, it would be too
difficult to assess and accurately characterize the risks associated
with these events. Additionally, in May 2025 EPA denied a citizen's
petition submitted under section 21 of TSCA for a section 6 rulemaking
proceeding primarily because it was premised on the potential for
accidental and catastrophic releases of a chemical which did not result
in regular and predictable exposures. See Hydrogen Fluoride; TSCA
Section 21 Petition for Rulemaking Under TSCA Section 6; Reasons for
Agency Response; Denial of Requested Rulemaking (90 FR 20575, May 15,
2025).
In the 2024 final rule, EPA added a provision at 40 CFR
702.39(d)(9) that requires the Agency to ``assess all exposure routes
and pathways relevant to the chemical substance under the conditions of
use, including those that are regulated under other federal statutes.''
The rationale for this addition was that TSCA sections 6(b)(4)(D) and
9(b)(1) do not specifically authorize EPA to exclude exposure routes or
pathways in the risk evaluation. Rather, EPA interpreted TSCA section
9(b)(1) as applying only to a subsequent risk management rulemaking
action after the completion of a final risk evaluation. EPA concluded
that the goal of the 2016 TSCA amendments was to create more certainty
and confidence in the safety of existing chemicals in the marketplace
and asserted that this goal would not be furthered by evaluating a
subset of a chemical substance's exposures or conditions of use.
In this action, EPA proposes to return to the approach taken in the
first 10 risk evaluations by deleting 40 CFR 702.39(d)(9), thereby
allowing EPA to exercise reasonable discretion in scoping a risk
evaluation to ensure timely and efficient completion of risk
evaluations. As discussed more extensively in Unit III.A.2 of this
document, EPA now believes that TSCA section 6(b)(4)(D) is best read as
permitting EPA some discretion as to the ``hazards, exposures,
conditions of use, and the potentially exposed or susceptible
subpopulations the Administrator expects to consider'' in the risk
evaluation. EPA proposes that this is the best interpretation of the
statute and that this approach better fulfills statutory objectives by
allowing EPA to focus its TSCA risk evaluations on the areas of
greatest concern without conducting evaluations that are redundant of
evaluations conducted by other EPA program offices. This is equally
important, whether considering conditions of use or exposure routes and
pathways. EPA proposes that meeting its obligations under the statutory
scheme requires that the Agency have discretion to exclude exposure
routes and pathways that the reasonably available information indicates
are unlikely to result in exposures that exceed de minimis levels.
Similarly, EPA proposes that meeting its obligations under the
statutory scheme requires that the Agency have discretion to exclude
exposure routes and pathways that have been or are being addressed by
other EPA-administered statutes and programs in order to avoid
duplicative assessments.
In the risk evaluations finalized in 2020 and early 2021, EPA
explained that the instruction in TSCA section 9(b)(1) for the
Administrator to ``coordinate actions taken under [TSCA] with actions
taken under other Federal laws administered [by EPA]'' (15 U.S.C.
2608(b)(1)) provided additional support for EPA's position that it has
discretion to tailor the scope of TSCA risk evaluations to focus on the
areas of greater concern and to avoid duplicative assessments (see,
e.g., Risk Evaluation for Methylene Chloride, sec. 1.4.2) (Ref. 21).
EPA asserted that further support is provided by the remaining text of
TSCA section 9(b)(1), which allows EPA to address risk through
statutory authorities other than TSCA ``[i]f the Administrator
determines that a risk to health or the environment associated with a
chemical substance or mixture could be eliminated or reduced to a
sufficient extent by actions taken under the authorities contained in
such other Federal laws'' (Ref. 21). Intra-agency coordination is
integral to ensuring that EPA actions are well-informed, effective, and
efficient. EPA explained that such coordination ``entails both an
identification of risk, and a referral of any risk that could be
eliminated or reduced to a sufficient extent under other EPA-
administered laws to the EPA offices responsible for implementing those
laws (absent a finding that it is in the public interest to protect
against the risk by actions taken under TSCA)'' (Ref. 21 at sec.
1.4.2.). EPA further explained that risks may be identified by EPA's
Office of Pollution Prevention and Toxics (OPPT) or another EPA office,
and the form of the identification could vary. For instance, OPPT may
find that one or more conditions of use for a chemical substance
present(s) a risk to human or ecological receptors through specific
exposure routes and/or pathways through a quantitative or qualitative
assessment of risk based on reasonably available information (which
might include, e.g., findings or statements by other EPA offices or
other federal agencies). Alternatively, risk could be identified by
another EPA office. For example, another EPA office administering non-
TSCA authorities may have sufficient data to indicate that a particular
condition of use presents risk to certain human or ecological
receptors, based on expected hazards and exposures. This risk finding
could be informed by information made available to the relevant office
under TSCA section 9(e), which supports cooperative actions through
coordinated information-sharing.
Upon further reflection, EPA believes that TSCA section 9(b)(1) is
best read as supporting the Agency's discretion to scope risk
evaluations in a manner that reflects existing activities of its other
program offices, consistent with the approach taken in the 2020-2021
risk evaluations under the 2017 final rule (see, e.g., Ref. 21). For
exposure pathways and risks that fall under the jurisdiction of other
EPA programs, such as those under the CAA or SDWA, EPA's proposal to
delete 40 CFR 702.39(d)(9) will allow the Agency to coordinate risk
evaluation and risk management activities under TSCA with activities
under other programs and to tailor its risk evaluations under TSCA to
facilitate that coordination. It is not an efficient use of EPA
resources to evaluate exposure routes and pathways under TSCA that have
been evaluated and are being managed by other EPA offices, or that
could be more effectively and efficiently assessed and managed by other
EPA offices. EPA proposes that

[[Page 45699]]

nothing in TSCA's text or structure requires such a result and that
duplicative assessments are contrary to the purpose of TSCA section
9(b) as amended in 2016 (see H. Rep. No. 114-176 at p. 28 (stating that
the 2016 TSCA amendments ``reinforce TSCA's original purpose of filling
gaps in Federal law,'' and citing new language in section 9(b)(2)
intended ``to focus the Administrator's exercise of discretion
regarding which statute to apply and to encourage decisions that avoid
confusion, complication, and duplication'')) (Ref. 26). So, for
example, if EPA began a TSCA risk evaluation on a chemical substance
that is also regulated as a Hazardous Air Pollutant under CAA section
112(42 U.S.C. 7412), 40 CFR 702.39(d)(9) currently would require
another robust assessment of the potential risks to the general
population through ambient air exposures.
EPA proposes that such duplication is not what Congress intended in
amending TSCA in 2016. Under this proposed rule, when an exposure
pathway of a chemical substance is not already evaluated and managed by
another EPA program, EPA may assess the particular exposure pathway
under TSCA. If EPA finds unreasonable risk, then it intends to,
pursuant to TSCA section 9(b), coordinate risk management under the
other EPA-administered statute when EPA determines that such risk can
be eliminated or reduced to a sufficient extent by another EPA-
administered statute, unless EPA determines it is in the public
interest to take action under TSCA. Likewise, when a condition of use
of a chemical substance is not evaluated, managed, or both, by another
Federal Agency, EPA intends to evaluate the condition of use and
determine whether it presents unreasonable risk. If EPA makes an
unreasonable risk finding, it will, in its discretion, follow the
procedures of TSCA section 9(a) to coordinate risk management.
EPA requests comments on all aspects of its proposed changes to 40
CFR 702.37(a) and 702.39(d) that relate to the conditions of use and
the exposure routes and pathways assessed in TSCA section 6(b) risk
evaluations. EPA also requests comment on whether this rule should
provide more specificity on EPA's coordination activities under TSCA
section 9, such as a requirement to document consultations with other
Federal agencies on draft scope documents and draft risk evaluations.
EPA requests comment on how EPA should consider, for TSCA section 6(b)
risk evaluation purposes, existing federal statutes and regulations and
risk assessments performed by other governmental entities. EPA requests
comment on whether the Agency should include regulatory text, such as
text that specifies that EPA has discretion to exclude conditions of
use as well as exposure pathways and routes. Further, EPA requests
comment on specific instances where EPA should exercise its authority
to exclude conditions of use and exposure pathways and routes. EPA also
requests comment on whether to add regulatory text that states that EPA
can coordinate actions with other federal laws administered by EPA to
ensure that chemical risks ``could be eliminated or reduced to a
sufficient extent'' by other EPA actions, pursuant to TSCA section
9(b). Finally, EPA welcomes suggested regulatory text that could be
considered. EPA is not currently aware of any significant reliance
interests in the 2024 amendments regarding these proposed changes,
given the 2024 amendments are fairly recent and apply almost
exclusively to internal Agency process.

B. Risk Determinations

The 2024 final rule included a number of revisions to regulatory
provisions on unreasonable risk determinations that EPA is now
proposing to modify. Specifically, EPA is proposing to revise 40 CFR
702.39(f)(1) to return to the risk determination approach in the 2017
final rule and original 2020-2021 risk evaluations, which determined
whether each condition of use of a chemical substance presents
unreasonable risk. As discussed in this Unit, EPA believes that the
provision in the 2024 final rule that requires EPA to make a single
risk determination on the chemical substance as a whole, rather than
determinations on the conditions of use, is not consistent with the
best reading of TSCA section 6, the Supreme Court's decision in Loper
Bright. More specifically, this proposal would replace the current
regulatory text with language that more closely tracks the version of
40 CFR 702.47 promulgated in the 2017 final rule. The new 40 CFR
702.39(f)(1) would read as follows: ``As part of the risk evaluation,
EPA will determine whether the chemical substance presents an
unreasonable risk of injury to health or the environment under the
conditions of use by making separate risk determinations for each
condition of use within the scope of the risk evaluation, either in a
single decision document or in multiple decision documents.'' EPA is
also proposing to revise 40 CFR 702.39(f)(3), which would be
superfluous, given that a risk determination would be made for each
condition of use. The rationale for these proposed changes is discussed
in this Unit. Proposed revisions to subparagraph (f)(2) are discussed
in Unit III.C.1 of this preamble.
1. Background
In each risk evaluation under TSCA section 6(b), EPA must determine
whether a chemical substance presents an unreasonable risk of injury to
health or the environment, without consideration of costs or other non-
risk factors, under the conditions of use. In making a risk
determination, EPA must evaluate relevant risk-related factors,
including, but not limited to: the severity of the hazard (e.g., the
nature of the hazard and irreversibility of the hazard); exposure-
related considerations (e.g., duration, intensity, and frequency of
exposure); the population exposed (including any potentially exposed or
susceptible subpopulations (PESS)); and the confidence in the
information used to inform the hazard and exposure values. This
includes an evaluation of the strengths, limitations, and uncertainties
associated with the information used to inform the risk estimate and
the risk characterization. Descriptions of risk estimates that are
based on highly refined hazard and exposure information would be
considered differently than risk estimates based on compounding
conservative assumptions on both hazard and exposure. The process of
determining unreasonable risk is made on a case-by-case basis, given
the inherently unique nature of risk evaluations, and benchmarks are
not treated as bright lines.
In proposing the 2017 rule (82 FR 7562, January 19, 2017) (Ref.
27), EPA included a regulatory provision on unreasonable risk
determinations that largely mirrored the language of TSCA section
6(b)(4)(A) and clarified that the phrase ``under the conditions of
use'' meant the conditions of use identified in the final scope
document published for the chemical substance. EPA also included an
exception in the 2017 final rule that would allow EPA to make an
``early determination'' for any specific condition of use that the
Agency had sufficient information to find that it presents an
unreasonable risk. Where such an early determination was made, the
Agency could initiate risk management under TSCA section 6(a) for that
specific condition of use immediately without waiting for the
completion of the risk evaluation for all covered conditions of use of
the chemical substance, which often takes multiple years (Ref. 27 at
pp. 7568 and 7578).

[[Page 45700]]

EPA received comments on the 2017 proposed rule asserting that such
early determinations of unreasonable risk for particular conditions of
use was unfair and represented an inherent bias ``toward Risk
Evaluation outcomes that require regulatory actions'' (Ref. 28). These
commenters encouraged the Agency to extend this concept of early risk
determinations to conditions of use found not to present an
unreasonable risk (Ref. 29 at p. 47). Other commenters discouraged the
Agency from allowing early determinations for conditions of use that do
not present unreasonable risk. According to these commenters, a
determination that a condition of use does not present unreasonable
risk cannot be made until the risks of all conditions of use have been
evaluated. One commenter argued that, while it is possible to conclude
that a chemical substance presents an unreasonable risk based on the
evaluation of a subset of uses before all of the conditions of use are
evaluated, the reverse is not true. The same commenter also expressed
concern over the potential for an early determination that a particular
condition of use does not present unreasonable risk foreclosing the
possibility of an aggregate exposure analysis across all of the
conditions of use (Ref. 29 at p. 47).
After considering these comments, EPA finalized language in the
2017 final rule at 40 CFR 702.47 providing that the Agency would
determine whether the chemical substance presents an unreasonable risk
of injury to health or the environment under each condition of use
within the scope of the risk evaluation, either in a single decision
document or in multiple decision documents (82 FR 33726) (Ref. 2). In
the preamble to the 2017 final rule, EPA explained that the Agency
would make individual risk determinations for each condition of use
identified as within the scope of the risk evaluation (82 FR 33726)
(Ref. 2 at p. 33744). EPA further explained in its Response to Public
Comments that the sooner the Agency can determine whether a particular
condition of use of a chemical substance does or does not present an
unreasonable risk, the better (Ref. 29 at p. 47). With respect to
comments about aggregate exposures, EPA explained that the Agency is
likely to take a variety of approaches depending on the chemical
substance at issue, including only making an early determination in
cases where EPA has decided not to do an aggregate exposure assessment,
or for those conditions of use where an aggregate exposure assessment
may not be appropriate (Ref. 29 at pp. 47 through 48).
Certain petitioners challenged the 2017 final rule's condition-of-
use-specific approach to risk determinations in the Safer Chemicals
litigation before the Ninth Circuit. 943 F.3d at 412. (Ref. 6). Among
other things, petitioners argued that issuing early determinations that
certain conditions of use present no unreasonable risk to health or the
environment would lead EPA to underestimate risk where exposure results
from multiple activities involving a chemical substance, such as when
the same individuals are exposed through multiple conditions of use
(e.g., in the workplace and in the home). According to petitioners,
such exposures may present unreasonable risk only when combined.
Consistent with EPA's explanation in the Response to Public Comments
document, the Agency responded that the 2017 final rule allowed EPA to
issue early determinations when appropriate and that EPA would consider
possible aggregate exposures in exercising such discretion, when
appropriate. For example, exposure to a chemical substance may truly
present no unreasonable risk under one condition of use, such as a
circumstance where inhalation is unlikely or impossible, but present an
unreasonable risk under another condition of use, such as a
circumstance where inhalation is prevalent. EPA also responded that the
2017 final rule also allowed EPA to issue early determinations, perform
an aggregate exposure assessment for a chemical substance, and then
issue one or more unreasonable risk determinations based on that
aggregate assessment (Ref. 30). EPA's further noted that TSCA
explicitly does not require EPA to perform an aggregate exposure
assessment for every risk evaluation; rather, TSCA section
6(b)(4)(F)(ii) directs EPA to describe whether aggregate or sentinel
exposures to a chemical substance under the conditions of use were
considered, and the basis for that consideration (15 U.S.C.
2605(b)(4)(F)(ii)).
The Ninth Circuit held in Safer Chemicals that petitioners'
argument was not justiciable because it was not clear that EPA would
conduct risk evaluations in a manner that, under petitioners' theory,
would underestimate risk from aggregate exposures. 943 F.3d at 413
(Ref. 6). Subsequent to the Ninth Circuit's decision, EPA made
individual risk determinations for each condition of use evaluated in
the first ten risk evaluations (i.e., the condition of use-specific
approach to risk determinations). This approach resulted in a mix of
findings that certain conditions of use for a chemical ``present
unreasonable risk'' while others ``do not present unreasonable risk.''
In 2021, however, EPA announced a different path forward for the
first ten risk evaluations (Ref. 9). In a series of Federal Register
notices and ``revised'' risk determinations, EPA reopened the risk
determinations for a vast majority of the first ten risk evaluations
to, among other things, replace determinations for each condition of
use with a single determination for each chemical substance. In doing
so, EPA asserted that revising the risk evaluation to reflect a single
determination of unreasonable risk did not require the Agency to
perform a new risk evaluation or revise any of its underlying analyses
in the risk evaluations. For each of EPA's revised risk determinations
where EPA found that the chemical substance presents unreasonable risk,
rather than specific conditions of use, every condition of use in the
risk evaluation proceeded to risk management, including with respect to
the conditions of use that the Agency had previously found did not
present unreasonable risk (e.g., Refs. 21, 31, and 32).
Although EPA indicated in its June 2021 announcement that it would
make a single risk determination on a chemical when it was ``clear that
majority of conditions of use warrant one determination,'' the preamble
to the 2023 proposed rule went a step further, stating that EPA now
believed that the plain reading of the statute mandates a single
determination for the chemical substance in every instance (88 FR
74292, October 30, 2023). The preamble also asserted that this approach
was consistent with Congressional intent and would enable the Agency's
risk determinations to better reflect the potential for combined
exposures across multiple conditions of use. In support of this
position, EPA noted that TSCA section 6(b)(4)(A) specifies that, in a
risk evaluation, the Agency must determine whether ``a chemical
substance'' presents an unreasonable risk of injury to health or the
environment ``under the conditions of use'' (15 U.S.C. 2605(b)(4)(A)).
EPA interpreted this language at the time as requiring an evaluation on
the chemical substance--not each of its conditions of use--and for the
evaluation to be based collectively on all of the chemical substance's
``conditions of use.'' EPA cited other provisions of TSCA section 6 to
support its new reading of the statute, including TSCA section 6(a),
which requires EPA to apply risk-

[[Page 45701]]

management requirements ``to the extent necessary so that the chemical
substance or mixture no longer presents such risk'' (15 U.S.C. 2605(a))
and which the Agency read as suggesting that the chemical substance
presents the unreasonable risk, not specific conditions of use. EPA
also referenced TSCA section 6(i)(1), which provides that ``a
determination by the Administrator under subsection (b)(4)(A) that a
chemical substance does not present an unreasonable risk of injury to
health or the environment shall be issued by order and considered to be
a final agency action, effective beginning on the date of issuance of
the order,'' and section 6(i)(2), which provides that ``a final rule
promulgated under subsection (a), including the associated
determination . . . that a chemical substance presents an unreasonable
risk of injury to health or the environment, shall be . . . a final
agency action, effective beginning on the date of promulgation of the
final rule'' (15 U.S.C. 2605(i)(1) and (2)). EPA asserted that both of
these provisions support the single risk determination approach because
they speak to whether the chemical substance presents unreasonable risk
without mentioning conditions of use.
EPA acknowledged in the 2023 proposal that there had been comments
critical of this approach on the revised risk determinations that EPA
issued for most of the first ten priority chemicals. The Agency noted
that some commenters thought that a singular risk determination could
create confusion as to whether all conditions of use or only certain
conditions of use of a chemical substance pose unreasonable risk, but
asserted that the potential confusion would be a communications issue
that EPA would strive to improve on. The Agency also noted that other
commenters expressed concern that EPA would use a single risk
determination for the chemical substance to regulate in an overly broad
manner, but asserted nevertheless that its statutory authority to
regulate chemicals under TSCA section 6(a) is available only ``to the
extent necessary so that the chemical substance or mixture no longer
presents [unreasonable] risk'' (15 U.S.C. 2605(a)).
During the comment period on the 2023 proposal, some commenters
supported the single risk determination approach and others opposed for
similar reasons as those asserted in comments on the revised risk
determinations. Industry commenters generally disagreed with EPA's
reading of the statute on this point. One commenter (Ref. 33) observed
that Congress found in TSCA section 2(a)(2) that ``among the many
chemical substances and mixtures which are constantly being developed
and produced, there are some whose manufacture, processing,
distribution in commerce, use, or disposal may present an unreasonable
risk of injury to health or the environment'' (15 U.S.C. 2601(a)(2)).
According to the commenter, this language reflects a congressional
recognition that particular applications of chemical substances have
the potential to pose unreasonable risk, not the chemical substances
themselves. Another commenter (Ref. 34) contended that the phrasing in
TSCA section 6(a), along with the fact that the tools provided therein
for managing unreasonable risks include both broader tools
(``prohibiting or otherwise restricting the manufacturing, processing,
or distribution in commerce of such substance or mixture'') and
narrower ones (``prohibiting or otherwise restricting the manufacture,
processing, or distribution in commerce of such substance or mixture
for . . . a particular use''), means that Congress envisioned use-by-
use determinations.
Industry commenters also contended that the legislative history of
the 2016 TSCA amendments did not support the single risk determination
approach as EPA claimed in the 2023 proposal. They cited floor
statements, including by Senator Inhofe, one of the legislation's key
sponsors, that ``there could be circumstances where EPA determines that
a chemical does not present an unreasonable risk in certain uses, but
does in others'' and that ``[p]reemption for no significant risk
determinations would apply as these determinations are made on a use-
by-use basis'' (Ref. 14 at p. S3521). They also cited statements by
Senator Vitter, another key sponsor, stating that ``[t]o be clear,
every condition of use identified by the Administrator in the scope of
the risk evaluation must, and will be either found to present or not
present an unreasonable risk'' (Ref. 14 at p. S3520).
In the 2024 Response to Comments, EPA disagreed with the industry
commenters on the proper interpretation of both the language of TSCA
and the legislative history of the 2016 amendments (Ref. 11). Instead,
the Agency finalized the language that currently appears at 40 CFR
702.39(f)(1), which requires EPA to issue a single risk determination
for the chemical substance for each risk evaluation.
2. Risk Determinations by Condition of Use
Upon further review of the 2024 final rule, EPA believes that TSCA
section 6 is best read as requiring that risk determinations be made
for each condition of use evaluated in the risk evaluation. There is
ample support for this position in the language of TSCA section
6(b)(4)(A), which provides that EPA ``shall conduct risk evaluations .
. . to determine whether a chemical substance presents an unreasonable
risk of injury to health or the environment, without consideration of
costs or other nonrisk factors, including an unreasonable risk to a
potentially exposed or susceptible subpopulation . . . under the
conditions of use.'' EPA proposes that by specifying ``risk
evaluations'' in the plural and ``a chemical substance'' in the
singular, Congress intended to authorize the Agency to perform more
than one risk evaluation, and therefore at least more than one risk
determination, for the same chemical. For example, EPA could re-
prioritize a chemical substance for which it already conducted a risk
evaluation on, resulting in a second risk evaluation of the chemical
substance. This clear authority to make multiple risk determinations is
incongruent with the single risk determination approach required by the
2024 final rule.
EPA further proposes that the condition-of-use by condition-of-use
approach to risk determinations is the only way to give independent
meaning to the phrase ``under the conditions of use,'' which Congress
added to TSCA section 6(b) and throughout the statute in the 2016
amendments. If Congress intended to require a single risk determination
for a chemical substance, there would have been no need to add the
phrase at the conclusion of this provision. EPA believes this reading
is also supported by TSCA section 3(4), which defines the phrase
``conditions of use'' as ``the circumstances, as determined by the
Administrator, under which a chemical substance is intended, known, or
reasonably foreseen to be manufactured, processed, distributed in
commerce, used, or disposed of'' (15 U.S.C. 2602(4)). Congress used
``circumstances'' in the plural and included a variety of contexts that
are necessarily different from one another and involve different
exposures, different potentially exposed populations, and ultimately
different risks.
Further, EPA proposes that the language in TSCA section 6(a)
supports this reading. TSCA Section 6(a) states that ``[i]f the
Administrator determines in accordance with subsection (b)(4)(A) that
the manufacture, processing, distribution in commerce, use, or disposal
of a chemical substance or mixture, or that any combination of such
activities, presents an

[[Page 45702]]

unreasonable risk of injury to health or the environment, the
Administrator shall by rule . . . apply one or more of the following
requirements to such substance or mixture to the extent necessary so
that the chemical substance or mixture no longer presents such risk''
(15 U.S.C. 2605(b)(4)(A)). The Agency believes that this language
contemplates that risk determinations will be made for each condition
of use. As pointed out by several commenters on the 2023 proposal and
original first ten chemical risk evaluations, it is difficult to ensure
that EPA has addressed unreasonable risk in accordance with TSCA
section 6(a) without first having determined whether each of the
conditions of use, or any combination of particular conditions of use,
presents or present an unreasonable risk to health or the environment
(Ref. 11).
More generally, making a risk determination for each condition of
use provides greater clarity and transparency for the regulated
community and the general public. The greater clarity afforded to the
regulated community by this approach fulfills the congressional policy
enshrined in TSCA itself by ensuring that EPA exercises its authority
to regulate unreasonable risk ``in such a manner as to not impede
unduly or create unnecessary economic barriers to technological
innovation'' (15 U.S.C. 2601(b)(3)). Indeed, Senate Report 114-67
states that the 2016 legislation was ``intended to enhance confidence
in the federal chemical regulatory system, provide EPA the authority
necessary for efficient and effective regulation of chemical risks, and
foster safety and innovation in commercial chemistry.'' The Senate
Report goes on to explain that the legislation is ``designed to ensure
that the competitive advantage of the U.S. chemical industry is not
eroded by regulatory mandates and that industry is subject to a more
consistent set of regulations that equally protect citizens across the
nation'' (Ref. 35 at p. 2).
In contrast, the single risk determination approach of the 2024
final rule does not appear to align with the stated goals of the 2016
TSCA amendments. As several industry commenters on the 2023 proposal
observed, the single risk determination approach is likely to result in
increased confusion on the part of the regulated community, workers,
consumers, and the general public (Refs. 36 and 37). EPA reiterated in
the 2024 final rule that where ``one or more conditions of use for the
chemical present an unreasonable risk, the chemical substance itself
necessarily presents an unreasonable risk'' (89 FR 37028) (Ref. 1 at p.
37035). In this way, however, the single risk determination required
under the 2024 final rule is uninformative for consumers wondering
whether their use of a chemical substance is safe, for workers
wondering whether the exposure controls associated with their
occupational exposure are sufficient to protect them (Ref. 36), or for
the chemical industry wondering whether and how EPA will regulate their
products (Ref. 37).
For example, the January 2025 final risk evaluation for di-isononyl
phthalate (1,2-benzenedicarboxylic acid, 1,2-diisononyl ester) (DINP)
found that the chemical substance presents an unreasonable risk of
injury to health because 4 conditions of use (out of a total of 47)
presented such unreasonable risk (Ref. 38). These 4 conditions of use
represent about 3 percent of the U.S. production volume of DINP, but
all production and all conditions of use of DINP were required to
proceed to risk management under the single risk determination
approach. The single risk determination approach obscures the fact that
EPA did not find that DINP presents unreasonable risk when used under
nearly all conditions of use, likely resulting in an unwarranted
stigmatization of the chemical substance and unnecessary consideration
at risk management.
As in the 2023 proposal, EPA acknowledged these concerns in the
2024 final rule and characterized them as a ``communications issue''
identified as a priority for improvement (89 FR 37028) (Ref. 1 at p.
37035). One communications improvement made by 2024 final rule is to
add a requirement for EPA to identify those conditions of use that
``significantly contribute'' to the unreasonable risk found in the risk
determination. According to the preamble, while this addition is not
necessarily a perfect indicator of how EPA will ultimately regulate, it
``should give industry stakeholders significant insight and more
certainty'' (id. at 37035).
Unfortunately, this addition to the 2024 final rule does not appear
likely to accomplish EPA's stated objective. EPA has received
consistent and widespread feedback that industry stakeholders are now
confused about what it means to ``significantly contribute'' to the
unreasonable risk presented by a chemical substance and how EPA will
regulate under TSCA section 6(a) conditions of use that significantly
contribute to the unreasonable risk (Ref. 39). EPA proposes that the
concept of ``significantly contributes'' is not based in the statutory
text and not defined in any way in the 2024 final rule, meaning it both
lacks a statutory basis and is vague, uninformative, and unpredictable
as applied.
Rather than relying on a vague term like ``significantly
contributes'' to identify the conditions of use of concern to EPA, and,
therefore, the conditions of use that EPA is likely to regulate in a
subsequent TSCA section 6(a) rule, EPA now believes that the better
approach is to use the language provided by the statute and clearly
state which conditions of use present an unreasonable risk to health or
the environment and which conditions of use do not present such an
unreasonable risk.
In addressing public comments on the confusion that could result
from the single risk determination approach, EPA cautioned in the 2024
final rule against placing too much emphasis on the communicative value
of the risk determination itself (89 FR 37028) (Ref. 1 at p. 37035). As
described therein, the primary purpose of a risk evaluation is not to
provide the public with guidance or suggested actions with respect to
particular chemical uses, but rather to serve as a scientific document
that informs EPA decisions on the regulatory actions needed to
sufficiently address any identified unreasonable risk to health or the
environment (89 FR 37028) (Ref. 1 at p. 37036). While this is true for
most sections of a risk evaluation, the risk determination section is a
policy section that is based on all of the inputs and assumptions of
the science in the risk assessment. The risk determination section also
includes explanations of scientific concepts that may not be familiar
to non-scientists, such as the strength of the scientific evidence
(Ref. 40 at p. 7). It is likely that many stakeholders use the risk
determination section of a TSCA section 6(b) risk evaluation to better
understand what conditions of use and exposures EPA evaluated, what EPA
determined based on its analyses, and what conditions of use present
unreasonable risk and are therefore likely to be regulated under TSCA
section 6(a).
The condition of use specific risk determination approach also
results in a TSCA section 9 that works as Congress intended. TSCA
section 9(d) states that EPA shall coordinate with the heads of other
federal agencies ``to achieve the maximum enforcement of [TSCA], while
imposing the least burdens of duplicative requirements'' to the
regulated community. Further, TSCA section 9(a) states that if EPA
makes an unreasonable risk determination and in EPA's discretion
determines that the risk could be ``prevented or reduced to

[[Page 45703]]

a sufficient extent'' by an action taken by another federal agency
under another federal law, EPA shall submit to the other federal agency
a report that includes a description of the risk and the condition(s)
of use or combination of conditions of use that EPA believes presents
such a risk. EPA's risk evaluations involve an analysis of multiple
industries and often include findings of unreasonable risk premised on
exposures to various occupational and consumer groups. In order for EPA
to achieve section 9's command to avoid burdening the regulated
community with ``duplicative requirements,'' EPA must be able to
efficiently consult with, and potentially refer risks to, other
agencies. The condition of use specific approach will allow for this by
ensuring that EPA knows precisely which agency could address the
unreasonable risk presented by a specific condition of use. This is in
sharp contrast to the single risk determination approach which
obfuscates the exact use or uses' role in the identified unreasonable
risk making it nearly impossible to effectively consult with other
agencies. Additionally, because it is highly unlikely that any single
agency would have the authority to address all the unreasonable risk
present in a single risk determination risk evaluation, EPA would be
unlikely to ever refer its risk evaluations to another agency. This
would of course render section 9(a) largely superfluous; a result
Congress did not intend. Thus, the condition-of-use by condition-of-use
approach ensures that section 9(a) operates as envisioned by Congress.
The condition-of-use by condition-of-use approach is also supported
by the text of TSCA section 18(c). TSCA section 18(c)(3)), which
implements and more directly articulates the bounds of the general
preemption provision in section 18(a)(1)(B), states that the scope of
permanent Federal preemption of State actions is limited to the
``hazards, exposures, risks, and uses or conditions of use of such
chemical substances included in any final action the Administrator
takes pursuant to section 6(a) or 6(i)(1)'' (15 U.S.C. 2617(c)(3)). In
the 2024 final rule, EPA interpreted the phrase ``included in any final
action'' to apply to any condition of use within the scope of the risk
evaluation which is the support document for any resulting section 6(a)
rule or section 6(i)(1) determination. In the context of a section 6(a)
rule, this is the case irrespective of whether those uses contribute to
the unreasonable risk and/or are targeted for risk management. (89 FR
37028) (Ref. 1 at p. 37036). EPA now proposes that this reading of the
phrase ``included in any final action'' was unnatural but necessary
because when making a single risk determination on the chemical
substance, no TSCA section 6(i) order would be issued for COUs that
were not regulated in the TSCA section 6(a) rule. In contrast, under
the condition-of-use by condition-of-use approach, a TSCA section 6(a)
rule and/or a TSCA section 6(i) order would be issued, so that every
COU within the scope of the risk evaluation is addressed in, that is,
`included in,'' one of those final agency actions and not just the risk
evaluation. Although the scope of permanent preemption is the same
under either approach, the condition-of-use by condition-of-use
approach achieves that same scope with a more natural reading of the
language ``included in any final action'' in TSCA section 18(c). Thus,
EPA proposes that the condition-of-use by condition-of-use approach
results in a more harmonious interpretation of the statute.
The preemption provisions added in the 2016 TSCA amendments are
important to the regulated community. As explained in Senate Report
114-67, stakeholders were concerned that TSCA had not ``fostered a
robust Federal chemical regulatory system,'' which resulted in
increased State actions on chemicals (Ref. 35 at p. 6). In the view of
these stakeholders, ``a proliferation of different State requirements
will create confusion for the general public, and significantly
increase the cost and burden of regulatory compliance for chemical
manufacturers, importers and users while failing to apply any
protections to more than a relatively small number of citizens'' (Ref.
35 at p. 6). A commenter on the 2023 proposal stated that ``[a] key
motivation for TSCA reform was to create one federal standard for
chemical regulation rather than a patchwork of state/local laws'' (Ref.
34 at p. 8). In a floor statement, Senator Inhofe expressed the view
that ``the preemption section of this bill was the most contentious
issue'' during the negotiations on the compromise bill that became the
Lautenberg Chemical Safety for the 21st Century Act and was ``the most
important linchpin in the final deal'' (Ref. 14 at p. S3521). Given the
importance of the preemption provisions and the more natural and
clearer interpretation of TSCA section 18(c) that results from the
condition-of-use by condition-of-use risk determination approach, EPA
now believes that it is the best interpretation of TSCA section
6(b)(4)(A).
For all of these reasons, EPA is proposing to return to making a
risk determination for each of the conditions of use covered by the
scope of a TSCA section 6(b) risk evaluation. Accordingly, EPA proposes
to revise 40 CFR 702.39(f)(1) to read as follows: ``As part of the risk
evaluation, EPA will determine whether the chemical substance presents
an unreasonable risk of injury to health or the environment under the
conditions of use by making separate risk determinations for each
condition of use within the scope of the risk evaluation, either in a
single decision document or in multiple decision documents.'' EPA also
proposes to revise 40 CFR 702.39(f)(3) because it would be superfluous,
given that a risk determination would be made for each condition of
use. EPA would replace the existing text in 40 CFR 702.39(f)(3) with
the risk-related factors described in following paragraph. EPA
emphasizes that this approach in no way precludes the Agency from
determining that a condition of use, while not presenting unreasonable
risk to health or the environment by itself, does present an
unreasonable risk in combination with other conditions of use, assuming
that the analyses in the risk evaluation support such a finding. As
discussed in Unit III.C.2 of this preamble, EPA may conduct an
aggregate exposure assessment where reasonably available information
supports such an assessment, and an aggregate exposure assessment could
support a finding that a combination of conditions of use, when
considered in the aggregate, present an unreasonable risk.
The preambles of the 2017 and 2024 final rules describe how EPA may
weigh a variety of factors in determining unreasonable risk, including,
but not limited to: the effects of the chemical substance on health and
human exposure to such substance under the conditions of use (including
cancer and non-cancer risks); the effects of the chemical substance on
the environment and environmental exposure under the conditions of use;
the population exposed (including any susceptible subpopulations), the
severity of hazard (the nature of the hazard, the irreversibility of
hazard), and uncertainties (89 FR 37028) (Ref. 1); (82 FR 33726) (Ref.
2). To provide more clarity and transparency surrounding what EPA
considers in determining whether unreasonable risk is presented, EPA is
proposing to codify the risk-related factors EPA considers in making an
unreasonable risk determination. Specifically, EPA is proposing to
replace the existing text in 40 CFR 702.39(f)(3) to require that EPA
consider

[[Page 45704]]

risk-related factors in determining whether unreasonable risk is
presented, including but not limited to: the severity of the hazard
(e.g., the nature of the hazard and irreversibility of the hazard);
exposure-related considerations (e.g., duration, intensity, and
frequency of exposure); the population exposed (including any
potentially exposed or susceptible subpopulations (PESS)); and the
confidence in the information used to inform the hazard and exposure
values, including an evaluation of the strengths, limitations, and
uncertainties associated with the information used to inform the risk
estimate and the risk characterization. These risk-related factors are
components of the risk evaluation, as outlined in 40 CFR 702.39 (c),
(d), and (e) with respect to the hazard assessment, exposure
assessment, and risk characterization, respectively.
EPA requests comment on this change to the regulatory requirements
for risk determinations discussed in this Unit as well as the changes
regarding occupational exposure assumptions discussed in Unit III.C.1.
In addition, EPA requests comments more generally on TSCA section
6(b)(4)(A) risk determinations, including whether there should be more
specific requirements for how EPA is to make and document its risk
determinations or whether EPA's proposal to specifically describe the
factors EPA considers when making risk determinations adds sufficient
clarity. Finally, while EPA is not proposing to define ``unreasonable
risk'' in this rulemaking, because, as discussed in Unit III.B.1 of
this preamble, risk determinations are case-by-case decisions, EPA
requests comment on whether this rule should include a definition of
the term and, if so, how the definition should be crafted in order to
preserve the unique nature of risk determinations. EPA also requests
comment on whether the change to the regulatory requirements for risk
determinations as well as the change s regarding occupational exposure
assumptions impacts any party's reliance interests on the 2024 final
rule.

C. Risk Evaluation Considerations

The 2024 final rule included a number of revisions to and
explanations of risk evaluation considerations that EPA is now
proposing to modify or clarify to be consistent with what the Agency
believes to be the best reading of the statute, pursuant to the Supreme
Court's decision in Loper Bright. EPA requests comment on all aspects
of these proposed regulatory modifications and clarifications.
1. Occupational Exposure Assumptions
EPA is proposing to amend 40 CFR 702.39(f)(2) to further clarify
how the Agency will take exposure controls, such as engineering
controls, administrative controls, and PPE, into account in conducting
risk evaluations and making risk determinations. The revised provision
would read as follows: ``In determining whether unreasonable risk is
presented, EPA's consideration of occupational exposure scenarios will
take into account reasonably available information on the
implementation and use of occupational exposure control measures such
as engineering and administrative controls and personal protective
equipment.''
In the initial risk determinations for the first ten TSCA chemical
risk evaluations, EPA used professional judgement and reasonably
available information to inform assumptions regarding whether workers
use PPE for each condition of use, and generally assumed that workers
were provided and used PPE in a manner that achieves the stated
assigned protection factor (APF) for respiratory protection, or used
impervious gloves for dermal protection, for many but not all
conditions of use. As defined in 29 CFR 1910.134(b), APF means ``the
workplace level of respiratory protection that a respirator or class of
respirators is expected to provide to employees when the employer
implements a continuing, effective respiratory protection program'' as
required by 29 CFR 1910.134. In support of this assumption, EPA relied
on public comments indicating that employers, particularly in the
industrial setting, implement engineering and administrative controls
and provide PPE to their employees, and follow established worker
protection standards (e.g., OSHA regulatory requirements,
recommendations from the American Conference of Governmental Industrial
Hygienists (ACGIH)). Parties in litigation as well as public commenters
on several TSCA risk evaluations argued that making risk determinations
based on assumptions of PPE conflates the risk evaluation and risk
management phases (e.g., Ref. 41). In June 2021, the Agency announced
it would be revisiting the risk determinations that were based on these
assumptions and noted its plans to consider information on use of PPE
and other ways industry protects its workers during the risk management
process (Ref. 9).
The 2024 final rule added a requirement at 40 CFR 702.39(f)(2) for
EPA to consider ``known and reasonably foreseen circumstances where
subpopulations of workers are exposed due to the absence or ineffective
use of personal protective equipment.'' This regulatory provision
further prohibits EPA from considering ``exposure reduction based on
assumed use of personal protective equipment as part of the risk
determination.'' As explained in the 2024 final rule, EPA believed that
the assumed use of PPE in a risk determination could lead to an
underestimation of the risk to workers for several reasons, including
that not all workers are covered by OSHA standards, their employers may
be out of compliance with OSHA standards, the PPE is not sufficient to
address the risk from the chemical, or the PPE does not fit or function
properly (89 FR 37028) (Ref. 1 at p. 37037). EPA also noted that many
of OSHA's chemical-specific permissible exposure limits have not been
updated in recent years.
While some commenters supported the proposed language, others
objected to the perceived assumption that there was widespread
noncompliance with OSHA requirements and interpreted the language to
prohibit EPA from considering reasonably available information on the
existing use of workplace exposure controls in the context of the risk
determination (Ref. 37).
EPA is proposing to amend 40 CFR 702.39(f)(2) because it is
unnecessarily confusing, it limits what EPA can consider in making an
unreasonable risk determination beyond the statutory prohibition on
considering non-risk factors, and it appears to be biased in favor of
reasonably available information that tends to show noncompliance with
mandatory and voluntary exposure control programs. TSCA section 26(k)
requires EPA to consider reasonably available information in making
risk evaluation decisions, including hazard and exposure information
pertaining to conditions of use. EPA intends to consider the reasonably
available information about personal protective equipment in each
chemical risk evaluation, given this information relates to the
exposures under the conditions of use and should not be cabined as
information only relevant to risk management. EPA's revision would
clearly comport with the requirement of TSCA to consider both
reasonably available information that indicates the absence or
ineffective use of worker exposure controls and information that
indicates that such controls are in place and are being implemented
properly. The revised 40 CFR 702.39(f)(2) would read as follows: ``In
determining whether unreasonable risk is presented,

[[Page 45705]]

EPA's consideration of occupational exposure scenarios will take into
account reasonably available information on the implementation and use
of occupational exposure control measures such as engineering and
administrative controls and personal protective equipment.''
2. Aggregate Exposure
TSCA section 6(b)(4)(F)(ii) directs EPA, when conducting a risk
evaluation, to ``describe whether aggregate or sentinel exposures to a
chemical substance under the conditions of use were considered, and the
basis for that consideration'' (15 U.S.C. 2605(b)(4)(F)(ii)). While
there is no mandate to conduct aggregate exposure analyses, EPA may
conduct aggregate exposure analyses at its discretion. The 2017 final
rule included a definition of ``aggregate exposure,'' which the 2024
final rule amended by removing the phrase ``to an individual'' for the
stated reason of promoting consistency with other definitions of the
term and by removing the word ``single'' for the stated reason that
TSCA allows the Agency to conduct risk evaluations on categories of
chemicals. EPA is not currently proposing to amend this definition but
requests comment on the utility and clarity of the current definition.
EPA is, however, proposing to delete the language from the 2024
final rule that requires the Agency, for all risk evaluations that do
not include an aggregate exposure assessment, to explain why. There are
a variety of reasons why EPA would not be able to perform an aggregate
exposure assessment, or why an aggregate exposure assessment would not
be appropriate for one or more conditions of use. For example, while
the 2024 Supplement to the Risk Evaluation for 1,4-Dioxane evaluated
combined exposure and risk from multiple sources of 1,4-dioxane in
surface water and combined exposure and risk across multiple facilities
in proximity releasing to air, EPA did not quantitatively aggregate
exposures across exposure routes and pathways due to uncertainties
around the additivity of effects (Ref. 16 at sec. 1.3.1.3.3.).
The proposed removal of the language that requires EPA to explain
the basis for not performing an aggregate exposure assessment, which is
in addition to the statutory directive to explain the basis for
performing an aggregate exposure assessment, is not meant to suggest
that EPA rejects the notion of performing aggregate exposure
assessments where appropriate and supported by the best available
science. Rather, the burden of explaining the absence of an aggregate
risk evaluation is significant and cumulative with the challenging
undertaking already required to complete a risk evaluation and is not
mandated by the statute. EPA is proposing to return to the language in
the 2017 final rule, which tracks the statute. Accordingly, EPA
proposes to delete 40 CFR 702.39(d)(8) and revise paragraph (d)(7) to
include aggregate exposures.
3. Potentially Exposed or Susceptible Subpopulations
TSCA section 6(b)(4)(A) requires EPA to evaluate risk to
``potentially exposed or susceptible subpopulation[s]'' (``PESS'')
identified as relevant to the risk evaluation by the Administrator,
under the conditions of use (15 U.S.C. 2605(b)(4)(A)). TSCA section
2(12) defines the term as ``a group of individuals within the general
population identified by the EPA who, due to either greater
susceptibility or greater exposure, may be at greater risk than the
general population of adverse health effects from exposure to a
chemical substance or mixture, such as infants, children, pregnant
women, workers, or the elderly'' (15 U.S.C. 2601(12)). The 2017 final
rule included this definition in 40 CFR 702.33. The 2024 final rule
added the phrase ``overburdened communities'' to the definition's list
of examples of groups of individuals that may be at greater risk. The
term ``overburdened communities'' was not defined, although EPA stated
that the term reflected its understanding and acknowledgment that a
chemical substance may disproportionately expose or disproportionately
impact communities already experiencing disproportionate and adverse
human health or environmental burdens. EPA further explained that this
``disproportionality can be as a result of greater exposure or
vulnerability to environmental hazards, lack of opportunity for public
participation, or other factors'' (89 FR 37028) (Ref. 1 at p. 37039).
The rationale given for adding this term to the regulatory definition
of PESS was that specifically including overburdened communities in the
regulatory definition would assist EPA and others (including the
public) in understanding, and would assist EPA in determining the
potential exposures, hazards and risks to the public, including for
overburdened communities associated with existing chemicals as part of
a TSCA section 6(b) risk evaluation (id. at 37052). EPA further
explained that the inclusion of overburdened communities among the
potentially exposed or susceptible subpopulations considered in a risk
evaluation will also enable EPA to design appropriate risk management
approaches to address the unreasonable risk that the Agency may
determine is presented by a chemical substance to all potentially
affected people, including any unreasonable risk that is
disproportionately borne by some communities.
As noted by several commenters on the 2023 proposed rule, the term
``overburdened communities'' as described by EPA is overbroad and could
be read to include exposures and susceptibilities not tied to the
specific chemical substance being evaluated (Ref. 33). Further, the
``vague and expansive scope'' of this term is likely to make it more
difficult for EPA to meet its statutory deadlines (Ref. 33). Mindful of
these concerns, EPA is proposing to remove the term ``overburdened
communities'' from the regulatory definition of PESS at 40 CFR 702.33
to better match the statutory text. EPA believes that the examples
provided in the statute, such as children, are illustrative and do not
prohibit EPA from identifying and considering additional PESS within
its risk evaluations. EPA specifically requests comment on the extent
to which the regulatory definition of PESS and other terms should
depart from the definitions provided by TSCA.

D. Science Policy and Scientific Standards

1. Peer Review
Science is the foundation of EPA's work on TSCA risk evaluations.
The quality and integrity of the science is vital to the credibility of
the Agency's decisions and processes, including but not limited to the
evaluation of risks from chemicals, determination of whether a
condition of use of a chemical substance presents an unreasonable risk,
decisions on how best to manage that risk, and ultimately the Agency's
effectiveness in pursuing its mission to protect human health and the
environment. One important element in ensuring that decisions are
consistent with the best available science and based on the weight of
scientific evidence is to have an open, transparent and independent
scientific peer review process along with opportunities for public
comment. 15 U.S.C. 2625(h), (i).
EPA has a long-standing history of peer review and has shown its
commitment to peer review in the TSCA program. TSCA section 26(o)
requires EPA to establish an advisory committee, known as the Science
Advisory Committee on Chemicals (SACC), to

[[Page 45706]]

provide independent advice and expert consultation with respect to the
scientific and technical aspects of issues relating to the
implementation of TSCA. EPA expects to continue to obtain scientific
advice and peer review from the SACC. The 2017 final rule explicitly
required peer review to be conducted on all risk evaluations, which the
Agency did for each of the first ten risk evaluations (82 FR 33726)
(Ref. 2 at 33743 through 33744). Reports from those peer review
committees proved instructive and resulted in more robust and
scientifically defensible products and improvements to EPA methods used
in the risk evaluation process.
The 2024 final rule made several revisions to the regulatory
provision for peer review. First, EPA removed the reference to specific
versions of guidance documents. The 2017 final rule specifically named
the EPA Peer Review Handbook 4th Edition 2015 (Ref. 42) and OMB's
Information Quality Bulletin for Peer Review (Ref. 43). As explained in
the 2023 proposal, EPA recognized that these documents may be updated
and/or their names modified and sought to avoid confusion as to which
guidance documents will be used. The 2024 final rule at 40 CFR 702.41
instead refers to ``applicable peer review policies, procedures,
guidance documents, and methods adopted by EPA and the OMB to serve as
the guidance for peer review activities.''
In the 2023 proposal, EPA discussed its experiences with the peer
reviews conducted for the risk evaluations for the first ten TSCA risk
evaluations and explained that, in the future, rather than peer
reviewing an entire risk evaluation, in adhering to applicable peer
review guidance, it may be appropriate for EPA to conduct peer review
on only portions or sections that constitute unreviewed influential
information (88 FR 74292, October 30, 2023) (Ref. 10 at p 74307). EPA
also explained that it expects that a TSCA risk evaluation may use peer
reviewed products (e.g., risk assessments, hazard assessments, models),
or portions thereof, conducted by another EPA office or other
authoritative body (e.g., state, national, or international programs)
that adhered to the best available science and weight of scientific
evidence standards. To clarify, EPA proposed revisions to 40 CFR 702.41
that would incorporate EPA's expectation that peer review activities
could be conducted on risk evaluations ``or portions thereof.''
As stated in the 2024 final rule, EPA received many comments on
these proposed changes, most of which did not support the new approach
to peer review. Commenters thought that the removal of the references
to specific guidance documents could potentially result in a lack of
clarity as to which policies, procedures, guidance documents, and
methods were applicable (Ref. 37). Commenters also thought that the
addition of the phrase ``or portions thereof'' and the framing of ``EPA
expects'' would give EPA too much flexibility, resulting in limited,
less transparent peer reviews, or potentially none at all. In response
to these comments, the 2024 final rule removed the reference to
specific guidance documents as proposed, and included the ``EPA
expects'' framing, but did not add the phrase ``or portions thereof''
(89 FR 37028) (Ref. 1 at 37041 through 37042).
EPA is not proposing to restore the 2017 final rule provisions for
peer review that referenced specific versions of guidance documents or
explicitly required peer review to be conducted on all risk evaluations
(i.e., did not include the ``EPA expects'' framing that allows EPA to
consider the complexity, novelty, and any prior peer review to
determine the appropriate approach to and scope of peer review to
apply). However, EPA is requesting comment on whether the 2017 language
describing peer review provisions should be restored, or whether other
amendments to the peer review provision should be considered. More
generally, EPA requests comment on how to ensure transparency and
accountability in the peer review of risk evaluations, consistent with
language in the EPA Peer Review Handbook 4th Edition 2015 (Ref. 42),
OMB's Information Quality Bulletin for Peer Review (Ref. 43), OMB's
Guidelines for Ensuring and Maximizing the Quality, Objectivity,
Utility, and Integrity of Information Disseminated by Federal Agencies
(Ref. 44), and OMB's Memorandum M-19-15, Memorandum for the Heads of
Executive Departments and Agencies: Improving Implementation of the
Information Quality Act.(Ref. 45).
2. Definitions
TSCA section 26(h) and (i) require the Agency to make decisions
under TSCA section 6 in a manner that is consistent with the best
available science and based on the weight of scientific evidence. 15
U.S.C. 2625(h) and (i). Specifically, TSCA section 26(h) requires that
in carrying out TSCA sections 4, 5, and 6, to the extent the Agency
makes decisions based on science, the Agency shall ``use scientific
information, technical procedures, measures, methods, protocols,
methodologies, or models, employed in a manner consistent with the best
available science.'' 15 U.S.C. 2625(h). The statute then lists
considerations: (1) The extent to which the scientific information,
technical procedures, measures, methods, protocols, methodologies, or
models employed to generate the information are reasonable for and
consistent with the intended use of the information; (2) The extent to
which the information is relevant for the Administrator's use in making
a decision about a chemical substance or mixture; (3) The degree of
clarity and completeness with which the data, assumptions, methods,
quality assurance, and analyses employed to generate the information
are documented; (4) The extent to which the variability and uncertainty
in the information, or in the procedures, measures, methods, protocols,
methodologies, or models, are evaluated and characterized; and (5) The
extent of independent verification or peer review of the information or
of the procedures, measures, methods, protocols, methodologies or
models. Id. Section 26(i) states ``the Administrator shall make
decisions under sections 4, 5, and 6 based on the weight of scientific
evidence.'' 15 U.S.C. 2625(i). TSCA does not define either ``best
available science'' or ``weight of scientific evidence'' and there is
no requirement in the statute to define them by rule.
During the development of the 2017 proposed rule, EPA received
input from stakeholders about the codification of definitions for these
terms (Refs. 2 and 29). Some noted that it is imperative that the
Agency have specific criteria which would allow for consistency and
transparency for how EPA will implement science. Others contended that
since interested persons may submit risk assessments to the Agency for
consideration (under TSCA section 26(l)(5)), it is necessary for the
Agency to provide a standard and expectation. 15 U.S.C. 2625(l)(5).
Many noted that there are a number of ways the Agency could and has
defined these terms across other statutory obligations and suggested
this could be both a reason to codify TSCA-specific definitions, or to
not codify them to avoid future limitations in implementation
approaches. Others thought that codification of specific process
definitions would limit the Agency's ability to adapt to the changing
science of risk evaluation, as well as the science that informs risk
evaluation.
The 2017 proposed rule did not include definitions for either of
these terms (82 FR 7562) (Ref. 27 at p. 7572), citing the need to
remain flexible to changing science and approaches.

[[Page 45707]]

Ultimately, EPA chose to codify definitions for both of these terms in
the final rule, explaining that this would instill confidence, increase
transparency, predictability, and provide the public with assurance
that EPA will adhere to the requirements of the statute (Ref. 29 at p.
11). The definition of ``best available science'' incorporated much of
the direction from TSCA section 26(h). In the response to comments
document, EPA further explained that the definitions that EPA had
chosen to codify, particularly for best available science and weight of
scientific evidence were not overly prescriptive, but instead captured
universal principles, which EPA did not think would restrict
flexibility or scientific advancement.
In the 2024 final rule EPA removed the definitions of best
available science and weight of the scientific evidence, explaining
that they were unnecessary and could act to limit the Agency's
flexibility and, therefore, its ability to meeting the science
standards of TSCA section 26. EPA discussed in detail the existing
requirements for using the best available science in TSCA section 6(b)
risk evaluations, including TSCA itself, as well as other guidance
documents such as OMB's Information Quality Guidelines (Ref. 44).
Similarly, EPA described four guidance documents that it would look to
in implementing the TSCA section 26(i) directive to make decisions
based on the weight of the scientific evidence (89 FR 37028) (Ref. 1 at
37044). EPA further explained that the 2017 final rule's definition of
weight of the scientific evidence appeared to conflate two ideas,
weight of the scientific evidence and systematic review. In the 2024
final rule EPA also described the expected application of systematic
review methods for identifying and assessing reasonably available
information to uphold TSCA's scientific standards for ``best available
science'' and ``weight of scientific evidence,'' including that the
Agency may consider existing assessments conducted by EPA or other
federal, state, or international authoritative bodies, determine
whether these existing assessments or reviews represent the best
available science as required under TSCA, and use portions of them to
directly inform a risk evaluation. More information on the rationale
for removing these definitions and not promulgating alternatives, or a
definition of systematic review, can be found in the 2024 final rule
(Id. at 37042 through 37045).
EPA is not proposing to restore the 2017 final rule definition for
best available science because much of the 2017 definition is
incorporated into 40 CFR 702.37(a). However, to enhance transparency in
its approach to risk evaluations, EPA is proposing to incorporate the
definition of ``weight of scientific evidence'' from section 2(e) of
Executive Order 14303 (Ref. 4). EPA believes that this definition
appropriately captures the intention behind TSCA sections 6(b)(4)(F)(v)
and 26(i). The proposed definition is ``an approach to scientific
evaluation in which each piece of relevant information is considered
based on its quality and relevance, and then transparently integrated
with other relevant information to inform the scientific evaluation
prior to making a judgment about the scientific evaluation. Quality and
relevance determinations, at a minimum, should include consideration of
study design, fitness for purpose, replicability, peer review, and
transparency and reliability of data.'' To meet the law's requirement
to base decisions in TSCA risk evaluations on the ``weight of the
scientific evidence,'' EPA expects to continue to rely on established
and peer reviewed Agency guidance documents or any successor documents
to guide weight of scientific evidence analysis under TSCA and to
provide a summary weight of scientific evidence narrative or
characterization, as described in the 2024 final rule (89 FR 37028)
(Ref. 1 at 37044). EPA's guidance documents all similarly describe the
weight of scientific evidence assessment as based on the strengths,
limitations, and interpretation of data available, information across
multiples lines of evidence and how these different lines of evidence
may or may not fit together when drawing conclusions. EPA is requesting
comment on all aspects of the proposed definition of ``weight of
scientific evidence'' and related terms, including the specific terms
within the definition and their meaning, and whether the consideration
of strengths, limitations, and uncertainties associated with
integrating lines of relevant information, is appropriately captured.
Additionally, the Agency seeks comment on whether the 2017 definition
for ``best available science'' should be restored, whether other
definitions for these terms should be considered, and whether EPA
should promulgate a definition of systematic review. EPA is also
requesting comment on how the Agency can apply systematic review
methods for TSCA risk evaluations that leverage consideration of
systematic review approaches and risk assessments from other EPA
offices and authoritative bodies. More generally, EPA requests comment
on how to ensure transparency and accountability in conducting risk
evaluations, including making risk determinations.
3. Occupational Exposure Value
The 2024 final rule preamble contained a discussion of how Existing
Chemical Exposure Limits (ECELs) were calculated for the first ten
priority chemicals, and how some ECELs were issued at a different time
than the risk evaluation on which they were based (89 FR 37028) (Ref. 1
at 37040). EPA also explained that these early ECELs were risk-based
occupational exposure values, and did not take non-risk factors into
account. Using the same terminology, EPA incorporated these ECELs into
the subsequent TSCA section 6(a) risk management rules (e.g., Ref. 46).
However, EPA soon realized that using the same term, ECEL, for both a
risk-based occupational exposure value and an enforceable regulatory
exposure limit applied in a risk management rule, where costs and other
non-risk factors may be considered, was confusing. As a result, EPA
stopped referring to the risk-based occupational exposure value as an
ECEL.
In the 2023 proposed rule EPA requested comment on how the Agency
could improve the transparency of risk-based occupational exposure
values derived from the risk evaluation process (88 FR 74292, October
30, 2023) (Ref. 10). Commenters generally expressed a preference for
more opportunity for public review and scientific input on how the
values are derived, and for a more formalized approach to developing
corresponding regulatory limits (89 FR 37028, May 30, 2024) (Ref. 1 at
p 37040). In response to these comments, EPA began issuing draft risk-
based occupational exposure values in, or concurrently with, draft risk
evaluations (Refs. 47 and 48). The 2024 final rule also provides, at 40
CFR 702.49(h), that where unreasonable risk to workers is identified
via inhalation, EPA will make available a calculated risk-based
occupational exposure value.
EPA is not specifically proposing changes to 40 CFR 702.49 at this
time. However, EPA is requesting comment on whether EPA should
establish occupational exposure values, and, if so, whether EPA should
do so as part of the risk evaluation for a chemical substance, or in
the subsequent risk management rule, or both. If both, EPA requests
comments on what considerations EPA should be taking into account in
moving from the value established as part of the risk evaluation to the
value established during risk management.

[[Page 45708]]

E. Process for EPA Revisions to Scope or Risk Evaluation Documents

The 2024 final rule established new procedures and criteria for
whether and how EPA would endeavor to revise or supplement final scope
documents, and draft or final risk evaluations. The 2017 final rule did
not provide for any special procedures or criteria for these actions.
Under the procedures in the 2024 final rule, changes to a draft scope
document or a draft risk evaluation will be described in the final
scope document or final risk evaluation. Changes to the scope of a risk
evaluation after the final scope document has been published will
either be described in the draft risk evaluation or separately in a
notice of availability published before the draft risk evaluation. So
far, none of this represents a departure from what EPA's practice has
been since implementation of the 2016 TSCA amendments began. For
example, information about an additional condition of use for 1,4-
dioxane was brought to EPA's attention after the scope of the risk
evaluation was published, and the expanded scope is discussed in the
draft risk evaluation (Ref. 49 at sec. 2.4.1.) The 2024 final rule
departed from established risk evaluation practice in promulgating new
criteria and procedures for revising final risk evaluations. 40 CFR
702.43(g)(3) states that ``EPA will generally not revise, supplement,
or reissue a final risk evaluation without first undergoing the
procedures at Sec. 702.7 to re-initiate the prioritization process for
that chemical substance, except where EPA has determined it to be in
the interest of protecting human health or the environment to do so . .
. .'' Should EPA determine to revise or supplement a final risk
evaluation, 40 CFR 702.43(g)(4) requires EPA to follow the procedures
set forth in the section, including publication of draft and final risk
evaluations and public comment periods.
One rationale given for the new procedures and criteria is to
provide greater certainty and transparency for stakeholders. However,
as explained in the 2023 proposal, given the tens of thousands of
existing chemical substances in commerce and EPA's responsibility to
assess and manage risks from those chemicals through a statutory
deadline-driven pipeline of prioritization, risk evaluation and risk
management activities, the new procedures and criteria for revising
final risk evaluations are intended to ensure that the Agency continues
to make forward progress on existing chemicals as Congress intended,
and does not drain already limited resources and divert attention from
other chemicals actively in the prioritization, risk evaluation or risk
management phases by continuously revisiting final risk evaluations (88
FR 74292, October 30, 2023) (Ref. 10 at p. 74311). In the 2023
proposal, EPA further explained that re-prioritizing a chemical
substance will provide the public with ample notice and opportunity to
engage, provide anticipatable milestones and process, and better
position the Agency to maintain a manageable workload (88 FR 74292,
October 30, 2023) (Ref. 10 at p. 74312). Nevertheless, EPA recognized
in the 2023 proposal that there may be instances where revisions to a
final risk evaluation outside of re-prioritization of a chemical are in
the interest of protecting human health and the environment.
While EPA appreciates the magnitude of the task assigned by
Congress in section 6 of TSCA, EPA maintains its authority to revise
final risk evaluations without going back through the prioritization
process, and not just because the revision is needed to protect human
health or the environment. Stakeholders, including States, the
regulated community, workers, consumers, and the general public, must
have confidence in EPA's risk evaluations under TSCA section 6,
including that they represent the best available science and are based
on the weight of the scientific evidence. To the extent that it becomes
apparent that a risk evaluation does not meet the statutory science
standards under TSCA section 26(h) and (i), EPA must be able to fix it.
The 2023 proposed rule provides an example of just such an instance, a
scientific error that meaningfully impacts the risk evaluation or the
Agency's ability to appropriately address risks through rulemaking (88
FR 74292, October 30, 2023) (Ref. 10 at p. 74312). The 2023 proposed
rule language implies that the only time EPA should revise a risk
evaluation that includes such a scientific error without going back
through prioritization is when the revision is needed to protect human
health or the environment. However, a scientific error could also
result in a determination that a condition of use presents an
unreasonable risk, when, in fact, it does not. Promulgating a TSCA
section 6(a) risk management rule based on that faulty risk
determination could entail burdensome requirements for industry without
the anticipated benefits and potentially impair the competitiveness of
the American manufacturing and industrial sectors or negatively impact
the health and safety of workers.
In conducting risk evaluations, or revising or supplementing final
risk evaluations, EPA is bound by the procedural requirements of TSCA
section 6 and the implementing regulations at 40 CFR part 702. As
described in this Unit, EPA believes that the limitation in 40 CFR
702.43(g)(3) on revising or supplementing final risk evaluations, as
promulgated in the 2024 final rule, is not consistent with EPA's
obligations under TSCA section 6 to assess and manage risks within the
statutory deadlines. For this reason, EPA is proposing to remove 40 CFR
702.43(g)(3) in its entirety, and to amend subparagraph (g)(3) to read
as follows: ``Final risk evaluations. When EPA supplements or revises,
in whole or in part, a final risk evaluation, EPA will follow the
procedures in this section including publication of a new draft and
final risk evaluation and solicitation of public comment in accordance
with Sec. Sec. 702.43(c) and (d), and peer review, as appropriate, in
accordance with Sec. 702.41.'' EPA requests comment on this change,
and also on whether there are circumstances that would allow for the
correction of a scientific error or to make other revisions without
reopening the risk evaluation or going back to the draft risk
evaluation stage. EPA requests comment on whether there should be
criteria for when a final risk evaluation should be revised, including
circumstances where EPA becomes aware of information that was developed
after the risk evaluation was finalized, as well as comment on
circumstances that would not warrant reopening the risk evaluation or
going back to the draft risk evaluation stage.
EPA requests comment on two alternatives to the above approach.
First, the Agency could remove all regulatory text related to revising
or supplementing existing risk evaluations and not replace the current
language with an analogous provision. Under this approach, EPA's
procedural framework rule would arguably satisfy the statutory
requirement to ``establish, by rule, a process to conduct risk
evaluations'' (15 U.S.C. 2605(b)(4)(C)) by setting out the process for
a risk evaluation while remaining silent on whether and how to revise
or supplement an evaluation. That would leave the Agency's assertion of
authority to revise and supplement an evaluation to particular cases.
While this approach would increase flexibility, EPA acknowledges that
the absence of such language could undermine interests in certainty and
predictability.
Second, the Agency could retain the current regulatory language
added in the

[[Page 45709]]

2024 final rule, except for the provision allowing EPA to supplement or
revise on an ad hoc basis in the interest of public health or the
environment. This approach would address the Agency's concerns with the
one-sided nature of the current regulatory allowance for
supplementation and revision while retaining the position that EPA
generally will not revise or supplement a risk evaluation without re-
prioritizing the chemical substance for a new risk evaluation. While
this approach would increase certainty and predictability, and helps to
ensure that the Agency proceeds to evaluate listed chemicals promptly
rather than revisiting already evaluated chemicals, EPA acknowledges
such a requirement would make it more difficult to update evaluations
and determinations for evaluated chemicals and conditions of use and
reduce the Agency's flexibility. EPA seeks comment on both alternative
approaches and any other approaches that commenters believe the Agency
should take to revisions and supplements in any final rule.

F. Requirements for Manufacturer-Requested Risk Evaluations

The 2024 final rule incorporated a number of changes to the
provisions for manufacturer-requested risk evaluations (MRREs). TSCA
section 6(b)(4)(C)(ii) allows a manufacturer or group of manufacturers
to request that the Agency conduct a risk evaluation of a chemical
substance (or category of substances) that they manufacture. TSCA
section 6(b)(4)(C)(ii) directs EPA to establish the ``form . . . manner
and . . . criteria'' for such requests by rule, which the Agency
finalized in 2017.
Many of the changes in the 2024 final rule were understandable
process changes based on EPA's experience in handling such requests and
on implementing TSCA section 6(b) in general. However, the 2024 final
rule includes new requirements for requesting manufacturers, including
requirements to provide all information ``known to or reasonably
ascertainable by'' the requesting manufacturer regarding a chemical
substance's conditions of use, hazards, and exposures. 40 CFR
702.43(a)(8) defines the phrase ``known to or reasonably ascertainable
by'' as including all information in the requesting manufacturer's
possession or control, as well as information obtained through a
thorough search of publicly available information, a reasonable inquiry
within the requester's entire organization, and a reasonable inquiry
outside of the requester's organization, including suppliers and
downstream users. Further, 40 CFR 702.43(e)(7) provides that, should
EPA determine that additional information is needed to carry out the
risk evaluation, the requester will provide the requested information,
withdraw the risk evaluation request, or request that EPA use its
authorities under TSCA sections 4, 8, or 11 to obtain the information
because the information is not reasonably ascertainable to the
requester.
As explained in the 2024 final rule, the process established for
MRREs in 2017 was challenging for EPA in a number of ways. The 2017
final rule allowed requests to contain information relevant only to
conditions of use of the chemical of interest to the requesting
manufacturer and also gave EPA a relatively short period of time in
which to grant or deny the request. Once EPA granted the request, the
statutory three-year clock for completing the risk evaluation began.
EPA further explained that the process effectively left the Agency with
the heavy burden of identifying the remaining conditions of use,
reviewing information that came in with the request, obtaining and
reviewing additional available literature, and determining any missing
information or data needs--all within a matter of months. The 2024
final rule asserted that, in addition to needing more information in
incoming requests, and additional time to properly review them and
determine any additional information needs prior to initiating the
evaluation, EPA also needed some flexibility in the process to pursue
data collection or development during the risk evaluation. In support,
EPA pointed to the process and timeframes that precede EPA-initiated
risk evaluations in prioritization, which provides a significant amount
of time to review and analyze available information, identify data gaps
and needs, and pursue various data gathering strategies, all before
initiating the risk evaluation and the associated deadlines.
While these challenges are evident with the MRREs that EPA has
received, the 2024 final rule's solution requires manufacturers to take
on the obligation to identify all of the conditions of use for the
chemical substance and to supply all of the information that would be
needed for EPA to perform the risk evaluation, including information
for conditions of use that they, their suppliers, and their customers
were not engaged in. The responsibility for determining the conditions
of use of a chemical substance and, thereby, the scope of the TSCA
section 6(b) risk evaluation, rests with EPA, and forcing manufacturers
to undertake some of the same tasks that EPA performs with regard to
risk evaluations that arise from the prioritization process is
inefficient.
EPA is therefore proposing to revise 40 CFR 702.45 to generally
scale back the information collection obligations that the 2024 final
rule imposed on requesting manufacturers, particularly with respect to
conditions of use that neither the manufacturers nor their customers
are engaged in. EPA would delete the statement at 702.45(a)(3) that
manufacturers are obligated to provide EPA with the information needed
to carry out the risk evaluation, as well as the statement at
702.45(a)(5) that manufacturers are obligated to develop, at any time
during the risk evaluation process, information that EPA determines is
necessary to complete the risk evaluation. TSCA provides EPA with
various information collection authorities, including section 4(a)(2)
that specifically allows EPA to require, by rule, order, or consent
agreement, the development of new information needed to support a TSCA
section 6(b) risk evaluation. This requirement may be directed at any
manufacturers and processors, including those manufacturing or
processing a chemical substance for a different purpose than the
requesting manufacturer.
For the same reasons, EPA is proposing to revise 40 CFR
702.45(a)(8) to read as follows: ``For purposes of this section,
information that is `known to or reasonably ascertainable by' the
requesting manufacturer(s) would include all information in the
requesting manufacturer's possession or control, plus all information
that a reasonable person similarly situated might be expected to
possess, control, or know.'' In EPA's view, this is a reasonable
measure of the information that requesting manufacturers ought to be
able to provide without significant additional effort. This definition
also comports with how the term is used in other TSCA regulations,
including 40 CFR 704.3. EPA requests comment on whether this or another
such standard is appropriate for manufacturer requests.
EPA is also proposing to modify the content requirements for
manufacturer requests to make it clear that requesters are only
obligated to submit information on the conditions of use that they have
identified in their request. So, for example, EPA would revise
702.45(c)(4) to read as follows: ``A description of the circumstances
for which the manufacturer is requesting that EPA conduct a risk
evaluation, all information known to or reasonably ascertainable by the
requesting manufacturer that supports the identification of the
requested

[[Page 45710]]

circumstances, and a rationale for why the requested circumstances
constitute conditions of use under 702.33.''
EPA is similarly proposing to revise 40 CFR 702.45(e) to limit
manufacturer information obligations to information about the
identified conditions of use, and to clarify the decisions EPA will
make regarding request completeness and the result of the request. In
general, EPA will grant requests that are complete and that provide
sufficient information to permit EPA to complete a risk evaluation on
the identified conditions of use. To the extent that EPA lacks other
information needed to perform a comprehensive risk evaluation on the
chemical substance, such as information about other conditions of use,
revised paragraph (e)(7) would require EPA to develop a strategy to
obtain the information and would permit EPA to delay initiation of the
risk evaluation on the chemical substance for up to one year in order
to obtain the information using available TSCA authorities.
Finally, EPA is revising paragraphs (g) and (k) to clarify that
manufacturer requests that are withdrawn before the request is granted
do not incur fees. EPA requests comment on all aspects of the changes
being proposed to the requirements for manufacturer-requested risk
evaluations.

G. Severability

EPA intends that the provisions of this proposed rulemaking would,
if finalized, be severable from one another. In the event that any
individual provision or part of this rulemaking is invalidated, EPA
intends that this would not render the entire rulemaking invalid, and
that any individual provisions that are finalized would continue to be
followed.

IV. Requests for Comment

EPA requests comment on all aspects of the proposal. Additionally,
within this proposal, the Agency is soliciting feedback from the public
on specific issues throughout this proposed rule. For ease of review,
this unit summarizes those specific requests for comment, with
numbering provided to help simplify referencing.
1. In Unit I.C., EPA requests comment on how the requirements of
this rule, when finalized, would apply to risk evaluations initiated
prior the effective date of the final rule, and whether these
requirements shall not apply retroactively to risk evaluations already
finalized.
2. In Unit I.E, EPA requests specific comment on the burden
estimate and assumptions associated with the calculation associated
with the burden (e.g., number of manufacturer requests for risk
evaluations that EPA expects). More generally, EPA requests comment on
whether and how the proposed rule would reduce burdens, and welcomes
detailed information, examples, and data addressing the impacts of the
rule.
3. In Unit III.A.2, EPA requests comment on the proposed amendments
to 40 CFR 702.37(a)(3) and (4), including whether the revisions are
sufficiently clear as to EPA's intent regarding appropriately scoped,
fit-for-purpose risk evaluations under TSCA section 6(b). EPA is also
interested in comments on how to address conditions of use that are
identified after the conclusion of a risk evaluation on a chemical
substance.
4. In Unit III.A.3, EPA requests comment on whether the Agency
should include regulatory text that specifies that EPA has discretion
to exclude conditions of use as well as exposure pathways and routes.
Further, EPA requests comment on specific instances where EPA should
exercise its authority to exclude conditions of use and exposure
pathways and routes. EPA also requests comment on whether to add
regulatory text that states that EPA can coordinate actions with other
federal laws administered by EPA to ensure that chemical risks ``could
be eliminated or reduced to a sufficient extent'' by other EPA actions,
pursuant to TSCA section 9(b). Finally, EPA welcomes suggested
regulatory text that could be considered.
5. In Unit III.B.2, EPA requests comment on the change to the
regulatory requirements for risk determinations discussed in Unit
III.B.2., as well as the changes regarding occupational exposure
assumptions discussed in Unit III.C.1. In addition, EPA requests
comments more generally on TSCA section 6(b)(4)(A) risk determinations,
including whether there should be more specific requirements for how
EPA is to make and document its risk determinations.
6. In Unit III.C, EPA requests comment on all aspects of the
proposed regulatory modifications and clarifications to provisions from
the 2024 final rule related to risk evaluation.
7. In Unit III.C.2 EPA requests comment on the clarity and utility
of the current definition of ``aggregate exposure.''
8. In Unit III.C.3, EPA requests comment on the extent to which the
regulatory definition of PESS and other terms should depart from the
definitions provided by TSCA.
9. In Unit III.D.1, EPA requests comment on whether the 2017
language describing peer review provisions should be restored, or
whether other amendments to peer review should be considered. More
generally, EPA requests comment on how to ensure transparency and
accountability in the peer review of risk evaluations.
10. In Unit III.D.2, EPA is requesting comment on all aspects of
the proposed definition of ``weight of scientific evidence'' and
related terms, including whether the 2017 definition for ``best
available science'' should be restored, whether other definitions for
these terms should be considered, and whether EPA should promulgate a
definition of systematic review. More generally, EPA requests comment
on how to ensure transparency and accountability in conducting risk
evaluations, including making of risk determinations.
11. In Unit III.D.3, EPA requests comment on whether EPA should
establish occupational exposure values, and, if so, whether EPA should
do so as part of the risk evaluation for a chemical substance, or in
the subsequent risk management rule, or both. If both, EPA requests
comments on what considerations should be taken into account in moving
from the value established as part of the risk evaluation to the value
established during risk management.
12. In Unit III.E, EPA requests comment on the proposed changes to
40 CFR 702.43(g), the two alternatives EPA is considering in lieu of
the proposed changes to 40 CFR 702.43(g), and also on whether there are
circumstances that would allow for the correction of a scientific error
without reopening the risk evaluation or going back to the draft risk
evaluation stage.
13. In Unit III.F, EPA requests comment on all aspects of the
changes being proposed to the requirements for manufacturer-requested
risk evaluations, including whether the proposed revision to 40 CFR
702.45(a)(8) regarding information known to, or reasonably
ascertainable by the manufacturer outlined in Unit III.F, or another
such standard, is appropriate for manufacturer requests.

V. References

1. U.S. EPA. Procedures for Chemical Risk Evaluation Under the Toxic
Substances Control Act (TSCA); Final Rule. Federal Register (89 FR
37028, May 3, 2024) (FRL-8529-02-OCSPP). <a href="https://www.govinfo.gov/content/pkg/FR-2024-05-03/pdf/2024-09417.pdf">https://www.govinfo.gov/content/pkg/FR-2024-05-03/pdf/2024-09417.pdf</a>
2. U.S. EPA. Procedures for Chemical Risk Evaluation Under the
Amended Toxic Substances Control Act; Final Rule. Federal Register
(82 FR 33726, July 20, 2017) (FRL-9964-38). https://

[[Page 45711]]

www.govinfo.gov/content/pkg/FR-2017-07-20/pdf/2017-14337.pdf
3. Executive Order 14219. Ensuring Lawful Governance and
Implementing the President's ``Department of Government Efficiency''
Deregulatory Initiative. Federal Register (90 FR 10583, February 19,
2025). <a href="https://www.govinfo.gov/content/pkg/FR-2025-02-25/pdf/2025-03138.pdf">https://www.govinfo.gov/content/pkg/FR-2025-02-25/pdf/2025-03138.pdf</a>
4. Executive Order 14303. Restoring Gold Standard Science. Federal
Register (90 FR 22601, May 29, 2025). <a href="https://www.govinfo.gov/content/pkg/DCPD-202500121/pdf/DCPD-202500121.pdf">https://www.govinfo.gov/content/pkg/DCPD-202500121/pdf/DCPD-202500121.pdf</a>
5. U.S. EPA. Information Collection Request (ICR) for the Proposed
Rule: Procedures for Chemical Risk Evaluation Under TSCA (RIN 2070-
AL27). EPA ICR No.: 2781.03 and OMB Control No. 2070-0231.
6. U.S. Court of Appeals for the Ninth Circuit. Safer Chemicals,
Healthy Families v. EPA, Nos. 17-72260, 17-72501, 17-72968, 17-
73290, 17-73383, 17-73390, Opinion. November 14, 2019. 943 F.3d 397,
425-426. <a href="https://cdn.ca9.uscourts.gov/datastore/opinions/2019/11/14/17-72260.pdf">https://cdn.ca9.uscourts.gov/datastore/opinions/2019/11/14/17-72260.pdf</a>
7. Safer Chemicals, Healthy Families; et al., v. U.S. Environmental
Protection Agency, No. 17-72260, 17-72501, 17-72968, 17-73290, 17-
73383, 17-73390, 2019 WL 6041996 (9th Cir. November 14, 2019).
8. Executive Order 13990. Protecting Public Health and the
Environment and Restoring Science to Tackle the Climate Crisis.
Federal Register (86 FR 7037, January 25, 2021). <a href="https://www.govinfo.gov/content/pkg/FR-2021-01-25/pdf/2021-01765.pdf">https://www.govinfo.gov/content/pkg/FR-2021-01-25/pdf/2021-01765.pdf</a>
9. U.S. EPA. EPA Announces Path Forward for TSCA Chemical Risk
Evaluations. Press Release. June 30, 2021. <a href="https://www.epa.gov/newsreleases/epa-announces-path-forward-tsca-chemical-risk-evaluations">https://www.epa.gov/newsreleases/epa-announces-path-forward-tsca-chemical-risk-evaluations</a>
10. U.S. EPA. Procedures for Chemical Risk Evaluation Under the
Toxic Substances Control Act (TSCA); Proposed Rule. Federal Register
(88 FR 74292, October 30, 2023) (FRL-8529-01-OCSPP). <a href="https://www.govinfo.gov/content/pkg/FR-2023-10-30/pdf/2023-23428.pdf">https://www.govinfo.gov/content/pkg/FR-2023-10-30/pdf/2023-23428.pdf</a>
11. U.S. EPA. Response to Public Comments on the Proposed Rule on
Procedures for Chemical Risk Evaluation Under the Toxic Substances
Control Act (TSCA). April 2024. Docket EPA-HQ-OPPT-2023-0496-0431.
<a href="https://www.regulations.gov/document/EPA-HQ-OPPT-2023-0496-0431">https://www.regulations.gov/document/EPA-HQ-OPPT-2023-0496-0431</a>
12. Executive Order 14154. Unleashing American Energy. Federal
Register (90 FR 8353, January 29, 2025). <a href="https://www.govinfo.gov/content/pkg/DCPD-202500121/pdf/DCPD-202500121.pdf">https://www.govinfo.gov/content/pkg/DCPD-202500121/pdf/DCPD-202500121.pdf</a>
13. U.S. EPA. EPA Announces Path Forward on Chemical Reviews to
Protect Public Health, Increase Efficiency and Follow the Law. Press
Release. March 10, 2025. <a href="https://www.epa.gov/newsreleases/epa-announces-path-forward-chemical-reviews-protect-public-health-increase-efficiency">https://www.epa.gov/newsreleases/epa-announces-path-forward-chemical-reviews-protect-public-health-increase-efficiency</a>
14. U.S. Senate Congressional Record, 162 Cong. Rec. S3511-01 (daily
ed. June 7, 2016). <a href="https://www.congress.gov/114/crec/2016/06/07/CREC-2016-06-07-pt1-PgS3511.pdf">https://www.congress.gov/114/crec/2016/06/07/CREC-2016-06-07-pt1-PgS3511.pdf</a>
15. U.S. EPA. Final Risk Evaluation for 1,4-Dioxane. EPA-740-R1-
8007. Office of Chemical Safety and Pollution Prevention.
Washington, DC. 2020. <a href="https://www.epa.gov/sites/default//files/2020-12/documents/1._risk_evaluation_for_14-dioxane_casrn_123-91-1.pdf">https://www.epa.gov/sites/default//files/2020-12/documents/1._risk_evaluation_for_14-dioxane_casrn_123-91-1.pdf</a>
16. U.S. EPA. Supplement to the Risk Evaluation for 1,4-Dioxane.
EPA-740-R-24-013. Office of Chemical Safety and Pollution
Prevention. November 2024. <a href="https://www.epa.gov/system/files/documents/2024-11/1.-1-4-dioxane-.-supplement-to-the-risk-evaluation-.-public-release-.-hero.-nov-2024.pdf">https://www.epa.gov/system/files/documents/2024-11/1.-1-4-dioxane-.-supplement-to-the-risk-evaluation-.-public-release-.-hero.-nov-2024.pdf</a>
17. U.S. EPA. Safer Chemical Ingredients List. Last Updated on
January 10, 2025. <a href="https://www.epa.gov/saferchoice/safer-ingredients">https://www.epa.gov/saferchoice/safer-ingredients</a>
18. U.S. EPA. TSCA Section 5(a)(3) Determination for Premanufacture
Notice (PMN) P-16-0218. May 6, 2025. <a href="https://www.epa.gov/system/files/documents/2025-05/p-16-0218_determination_non-cbi_final.pdf">https://www.epa.gov/system/files/documents/2025-05/p-16-0218_determination_non-cbi_final.pdf</a>
19. U.S. EPA. Problem Formulation of the Risk Evaluation for 1,4-
Dioxane. EPA/740/R1/7012. Office of Chemical Safety and Pollution
Prevention. Washington, DC. 2018. <a href="https://www.regulations.gov/document/EPA-HQ-OPPT-2016-0723-0064">https://www.regulations.gov/document/EPA-HQ-OPPT-2016-0723-0064</a>
20. U.S. EPA. Summary of Public Comments Received on the Draft
Scopes of the Risk Evaluations for Twenty Chemical Substances Under
the Toxic Substances Control Act (TSCA); Response to Public
Comments. September 2020. <a href="https://www.regulations.gov/document/EPA-HQ-OPPT-2019-0131-0054">https://www.regulations.gov/document/EPA-HQ-OPPT-2019-0131-0054</a>
21. U.S. EPA. Risk Evaluation for Methylene Chloride
(Dichloromethane, DCM) CASRN: 75-09-2. EPA-740-R1-8010. Office of
Chemical Safety and Pollution Prevention. June 2020. <a href="https://www.epa.gov/sites/default/files/2020-06/documents/1_mecl_risk_evaluation_final.pdf">https://www.epa.gov/sites/default/files/2020-06/documents/1_mecl_risk_evaluation_final.pdf</a>
22. TSCA Science Advisory Committee on Chemicals. Peer Review for
EPA Draft Risk Evaluation for Methylene Chloride. Meeting Minutes
and Final Report No. 2020-1. March 2020. <a href="https://www.regulations.gov/document/EPA-HQ-OPPT-2019-0437-0080">https://www.regulations.gov/document/EPA-HQ-OPPT-2019-0437-0080</a>
23. Comment from the Attorneys General of Massachusetts, California,
Hawaii, Maine, Maryland, New Jersey, New York, Oregon, Vermont,
Washington, and the District of Columbia. Comments submitted to EPA
in response to Notice of Availability on Problem Formulations for
the Risk Evaluations to be Conducted Under the Toxic Substances
Control Act and General Guiding Principles to Apply Systematic
Review in TSCA Risk Evaluations. <a href="https://www.regulations.gov/comment/EPA-HQ-OPPT-2016-0723-0074">https://www.regulations.gov/comment/EPA-HQ-OPPT-2016-0723-0074</a>
24. Safer Chemicals, Healthy Families et al. Comments submitted to
EPA on Notice of Availability on Risk Evaluation Problem
Formulations Documents for Ten Chemical Substances under the Toxic
Substances Control Act. <a href="https://www.regulations.gov/docket/EPA-HQ-OPPT-2016-0723-0089">https://www.regulations.gov/docket/EPA-HQ-OPPT-2016-0723-0089</a>
25. U.S. EPA. Draft TSCA Screening Level Approach for Assessing
Ambient Air and Water Exposures to Fenceline Communities Version
1.0. EPA/744/D/22/001. Washington, DC. 2022. <a href="https://www.epa.gov/system/files/documents/2022-01/draft-fenceline-report_sacc.pdf">https://www.epa.gov/system/files/documents/2022-01/draft-fenceline-report_sacc.pdf</a>
26. U.S. House Report on the TSCA Modernization Act of 2015,
H.R.2576, H.Rept. 114-176. June 23, 2015. <a href="https://www.congress.gov/congressional-report/114th-congress/house-report/176/1">https://www.congress.gov/congressional-report/114th-congress/house-report/176/1</a>
27. U.S. EPA. Procedures for Chemical Risk Evaluation Under the
Amended Toxic Substances Control Act; Proposed Rule. Federal
Register (82 FR 7562, January 19, 2017) (FRL-9957-75). <a href="https://www.govinfo.gov/content/pkg/FR-2017-01-19/pdf/2017-01224.pdf">https://www.govinfo.gov/content/pkg/FR-2017-01-19/pdf/2017-01224.pdf</a>
28. American Cleaning Institute. Public Comment. Comments on
Procedures for Chemical Risk Evaluation Under the Amended Toxic
Substances Control Act; Proposed Rule. Docket EPA-HQ-OPPT-2016-0654-
0073. March 2017. <a href="https://www.regulations.gov/comment/HQ-OPPT-2016-0654-0073">https://www.regulations.gov/comment/HQ-OPPT-2016-0654-0073</a>
29. U.S. EPA. Response to Public Comments on the Proposed Rule on
Procedures for Chemical Risk Evaluation under the Amended Toxic
Substances Control Act. July 2017. Docket EPA-HQ-OPPT-2016-0654-
0109. <a href="https://www.regulations.gov/document/EPA-HQ-OPPT-2016-0654-0109">https://www.regulations.gov/document/EPA-HQ-OPPT-2016-0654-0109</a>
30. Brief of Respondents U.S. EPA et al., Safer Chemicals, Healthy
Families, et al. v. U.S. EPA, et al., No. 17-72260 (9th Cir. August
8, 2018).
31. U.S. EPA. Risk Evaluation for Perchloroethylene (Ethene,
1,1,2,2-Tetrachloro-) CASRN: 127-18-4. EPA-740-R1-8011. Office of
Chemical Safety and Pollution Prevention. December 2020. <a href="https://www.epa.gov/sites/default/files/2020-12/documents/_risk_evaluation_perchloroethylene_pce_casrn_127-18-4_0.pdf">https://www.epa.gov/sites/default/files/2020-12/documents/_risk_evaluation_perchloroethylene_pce_casrn_127-18-4_0.pdf</a>
32. U.S. EPA. Risk Evaluation for Trichloroethylene. CASRN: 79-01-6.
EPA-740-R1-8008. Office of Chemical Safety and Pollution Prevention.
November 2020. <a href="https://www.epa.gov//default/files/2020-11/documents/1._risk_evaluation_for_trichloroethyene_tce_casrn_79-01-6.pdf">https://www.epa.gov//default/files/2020-11/documents/1._risk_evaluation_for_trichloroethyene_tce_casrn_79-01-6.pdf</a>
33. Center for Environmental Accountability. Public Comment.
Comments on Procedure for Chemical Risk Evaluation Under the Toxic
Substances Control Act (TSCA) Proposed Rule. Docket EPA-HQ-OPPT-
2023-0496-0251. December 2023. <a href="https://www.regulations.gov//HQ-OPPT-2023-0496-0251">https://www.regulations.gov//HQ-OPPT-2023-0496-0251</a>
34. Silicones Environmental, Health and Safety Center (SEHSC).
Public Comment Re: Comments on Procedures for Chemical Risk
Evaluation Under the Toxic Substances Control Act (TSCA). Docket
EPA-HQ-OPPT-2023-0496-

[[Page 45712]]

0246. December 2023. <a href="https://www.regulations.gov//EPA-HQ-OPPT-2023-0496-0246">https://www.regulations.gov//EPA-HQ-OPPT-2023-0496-0246</a>
35. U.S. Senate Report on the Frank R. Lautenberg Chemical Safety
for the 21st Century Act, S.697, S.Rept. 114-67. June 18, 2015.
<a href="https://www.congress.gov/congressional-report/114th-congress/senate-report/67/1">https://www.congress.gov/congressional-report/114th-congress/senate-report/67/1</a>
36. Household & Commercial Products Association (HCPA). Public
Comment Re: Procedures for Chemical Risk Evaluation Under the Toxic
Substances Control Act (TSCA). Docket EPA-HQ-OPPT-2023-0496-0239.
December 2023. <a href="https://www.regulations.gov//EPA-HQ-OPPT-2023-0496-0239">https://www.regulations.gov//EPA-HQ-OPPT-2023-0496-0239</a>
37. American Chemistry Council (ACC). Public Comment Re: Proposed
rule, Procedures for Chemical Risk Evaluation Under the Toxic
Substances Control Act (TSCA). Docket EPA-HQ-OPPT-2023-0496-0249.
December 2023. <a href="https://www.regulations.gov/comment/EPA-HQ-OPPT-2023-0496-0249">https://www.regulations.gov/comment/EPA-HQ-OPPT-2023-0496-0249</a>
38. U.S. EPA. Risk Evaluation for Diisononyl Phthalate (DINP).
CASRNs 28553-12-0 and 68515-48-0. EPA-740-R-25-001. January 2025.
<a href="https://www.epa.gov/system/files/documents/2025-01/01.-dinp-.-risk-evaluation-.-public-release-.-hero-.-jan-2025.pdf">https://www.epa.gov/system/files/documents/2025-01/01.-dinp-.-risk-evaluation-.-public-release-.-hero-.-jan-2025.pdf</a>
39. Brief of the Chamber of Commerce of the U.S. and the National
Association of Manufacturers as Amici Curiae in Support of
Petitioners and Vacatur. United Steel, Paper and Forestry, Rubber,
Manufacturing, Energy, Allied Industrial and Service Workers
International Union, AFL-CIO, et al. v. U.S. EPA, et al., No. 24-
1151 (D.C. Cir. October 17, 2024).
40. U.S. EPA. Unreasonable Risk Determination of the Risk Evaluation
for Formaldehyde. EPA-740-R24-017. Office of Chemical Safety and
Pollution Prevention. Washington, DC. December 2024. <a href="https://www.epa.gov/system/files/documents/2025-01/37.-formaldehyde-.-unreasonable-risk-determination-.-public-release-.-hero-.-dec-2024.pdf">https://www.epa.gov/system/files/documents/2025-01/37.-formaldehyde-.-unreasonable-risk-determination-.-public-release-.-hero-.-dec-2024.pdf</a>
41. The Environmental Defense Fund. Comments on the Draft Risk
Evaluation of 1,4-Dioxane. Docket EPA-HQ-OPPT-2019-0238-0058. August
30, 2019. <a href="https://www.regulations.gov/comment/EPA-HQ-OPPT-2019-0238-0058">https://www.regulations.gov/comment/EPA-HQ-OPPT-2019-0238-0058</a>
42. U.S. EPA. Peer Review Handbook (4th Edition). EPA/100/B-15/001.
Science and Technology Policy Council. Washington, DC. October 2015.
<a href="https://www.epa.gov/sites/default/files/2020-08/documents/epa_peer_review_handbook_4th_edition.pdf">https://www.epa.gov/sites/default/files/2020-08/documents/epa_peer_review_handbook_4th_edition.pdf</a>
43. OMB. Final Information Quality Bulletin for Peer Review; Final
Bulletin. Federal Register (70 FR 2664, January 14, 2005). <a href="https://www.govinfo.gov/content/pkg/FR-2005-01-14/pdf/05-769.pdf">https://www.govinfo.gov/content/pkg/FR-2005-01-14/pdf/05-769.pdf</a>
44. OMB. Guidelines for Ensuring and Maximizing the Quality,
Objectivity, Utility, and Integrity of Information Disseminated by
Federal Agencies; Republication; Final Guidelines. Federal Register
(67 FR 8452, February 22, 2002). <a href="https://www.govinfo.gov/content/pkg/FR-2002-02-22/pdf/R2-59.pdf">https://www.govinfo.gov/content/pkg/FR-2002-02-22/pdf/R2-59.pdf</a>
45. OMB. Memorandum M-19-15, Memorandum for the Heads of Executive
Departments and Agencies: Improving Implementation of the
Information Quality Act. April 24, 2019. <a href="https://www.whitehouse.gov/wp-content/uploads/2019/04/M-19-15.pdf">https://www.whitehouse.gov/wp-content/uploads/2019/04/M-19-15.pdf</a>
46. U.S. EPA. Methylene Chloride; Regulation Under the Toxic
Substances Control Act (TSCA); Final Rule. Federal Register (89 FR
39254, May 8, 2024) (FRL-8155-01-OCSPP). <a href="https://www.govinfo.gov/content/pkg/FR-2024-05-08/pdf/2024-09606.pdf">https://www.govinfo.gov/content/pkg/FR-2024-05-08/pdf/2024-09606.pdf</a>
47. U.S. EPA. Draft Risk Evaluation for Tris(2-chloroethyl)
Phosphate (TCEP). EPA-740-D-23-002. Office of Chemical Safety and
Pollution Prevention. Washington, DC. December 2023. <a href="https://www.regulations.gov/document/EPA-HQ-OPPT-2023-0265-0030">https://www.regulations.gov/document/EPA-HQ-OPPT-2023-0265-0030</a>
48. U.S. EPA. Existing Chemical Exposure Limit (ECEL) for
Occupational Use of 1,4-Dioxane. Docket EPA-HQ-OPPT-2022-0905-0039.
August 8, 2023. <a href="https://www.regulations.gov/document/EPA-HQ-OPPT-2022-0905-0039">https://www.regulations.gov/document/EPA-HQ-OPPT-2022-0905-0039</a>
49. U.S. EPA. Draft Risk Evaluation for 1,4-Dioxane. EPA-740-R1-
8007. Office of Chemical Safety and Pollution Prevention.
Washington, DC June 2019. <a href="https://www.regulations.gov//EPA-HQ-OPPT-2019-0238-0011">https://www.regulations.gov//EPA-HQ-OPPT-2019-0238-0011</a>
50. U.S. EPA. Information Collection Request (ICR) for the Final
Rule: Procedures for Chemical Risk Evaluation Under TSCA (RIN 2070-
AL27). EPA ICR No. 2781.02 and OMB Control No. 2070-0231. June 24,
2024.

VI. Statutory and Executive Order Reviews

Additional information about these statutes and Executive Orders
can be found at <a href="https://www.epa.gov/laws-regulations/laws-and-executive-orders">https://www.epa.gov/laws-regulations/laws-and-executive-orders</a>.

A. Executive Orders 12866: Regulatory Planning and Review and 13563:
Improving Regulation and Regulatory Review

This action is a significant regulatory action that was submitted
to OMB for review under Executive Orders 12866 (58 FR 51735, October 4,
1993) and 13563 (76 FR 3821, January 11, 2011). Any changes made in
response to Executive Order 12866 review have been documented in the
docket. EPA prepared an analysis of the potential costs and burdens
associated with this action. This analysis can be found in Unit VI.C.

B. Executive Order 14192: Unleashing Prosperity Through Deregulation

This action is expected to be an Executive Order 14192 deregulatory
action. Details on the estimated direct cost savings of this proposed
rule can be found in Unit I.E and in the Information Collection Request
(ICR) document entitled ``Procedures for Requesting a Chemical Risk
Evaluation under TSCA (Proposed Rule)'' (Ref. 5). Additionally,
although EPA's determinations as to whether a chemical presents
unreasonable risk under its conditions of use are necessarily made
without consideration of cost or other non-risk factors through the
course of a TSCA risk evaluation, by proposing to amend the procedural
rule to reassert EPA's discretion (e.g., to determine the scope of the
risk evaluation and to make a risk determination for each condition of
use of a chemical substance instead for the chemical substance as a
whole), the Agency anticipates that it could also be responsive to
public comments that have suggested that unreasonable risk
determinations formulated under the 2024 final rule would necessarily
result in regulatory actions that would be overbroad and overly
burdensome compared to potential actions in response to unreasonable
risk determinations that are tailored to individual conditions of use.

C. Paperwork Reduction Act (PRA)

The information collection activities in this proposed rule have
been submitted for approval to OMB under the PRA, 44 U.S.C. 3501 et
seq. EPA has prepared a new rule-related Information Collection Request
(ICR) document entitled ``Procedures for Requesting a Chemical Risk
Evaluation under TSCA (Proposed Rule)'' and is identified by EPA ICR
No. 2781.03, to replace an existing approved ICR. You can find a copy
of the new ICR document (Ref. 5) in the docket for this rule, and it is
briefly summarized here.
The information activities related to the current requirements for
manufacturer-requested risk evaluations are already approved by OMB in
an ICR entitled, ``Procedures for Requesting a Chemical Risk Evaluation
under TSCA'' (EPA ICR No. 2781.02 and OMB Control No. 2070-0231) (Ref.
50). The proposed rule replacement ICR addresses the information
collection requirements contained in the current regulations as well as
in the amendments identified in this proposed rule. As addressed in the
currently approved ICR and pursuant 40 CFR 702, subpart B, the
information collection activities are those carried out by a chemical
manufacturer in requesting a specific chemical risk evaluation under
TSCA be conducted by EPA. EPA established the process for conducting
risk evaluations under TSCA. Chemicals that will undergo this
evaluation include chemicals designated by the Agency as high-priority
in accordance with 40 CFR 702, subpart A, as well as chemicals for
which EPA has granted requests made

[[Page 45713]]

by manufacturers to have the chemicals evaluated under EPA's risk
evaluation process. The replacement ICR addresses proposed amendments
to information requirements for manufacturer-requested risk
evaluations, including proposed amendments to information requirements
addressing joint submissions, the scope of the requested risk
evaluation, and the information to be provided in support of the
requested risk evaluation, and fee payment. Please see Unit III.F. for
additional information about these proposed amendments.
This ICR revision addresses adjustments to the estimated time for
activities and wage rates related to the current regulatory
requirements as approved under OMB Control No. 2070-0202. In addition,
the ICR revision addresses program changes related to the proposed
amendments, including changes to content requirements for manufacturer-
requested risk evaluation request and associated process changes. The
estimated annual burden approved by OMB under OMB Control No. 2070-0231
is 166 hours. The total estimated annual respondent burden being
proposed in the replacement ICR is 166 hours, a net decrease of 0
hours. Certain information included with a manufacturer-requested risk
evaluation may be claimed as TSCA CBI in accordance with TSCA section
14 (15 U.S.C. 2613), and any such claims must be substantiated in
accordance with the Act.
Respondents/affected entities: Persons that manufacture chemical
substances and request a chemical be considered for risk evaluation by
EPA. Such persons may voluntarily request a risk evaluation but would
be required to comply with the requirements for such a request. See
Unit I.A.
Respondent's obligation to respond: Voluntary (15 U.S.C.
2605(b)(4)).
Estimated number of respondents: 1 (per year).
Frequency of response: On occasion.
Total estimated burden: 166 hours (per year). Burden is defined at
5 CFR 1320.3(b).
Total estimated cost: $91,831 (per year), includes $0 annualized
capital or operation and maintenance costs.
An agency may not conduct or sponsor, and a person is not required
to respond to, a collection of information unless it displays a
currently valid OMB control number. The OMB control numbers for the
EPA's regulations in 40 CFR are listed in 40 CFR part 9.
Submit your comments on the Agency's need for this information, the
accuracy of the provided burden estimates and any suggested methods for
minimizing respondent burden to EPA using the docket identified at the
beginning of this rule. EPA will respond to any ICR-related comments in
the final rule. You may also send your ICR-related comments to OMB's
Office of Information and Regulatory Affairs using the interface at
<a href="https://www.reginfo.gov/public/do/PRAMain">https://www.reginfo.gov/public/do/PRAMain</a>. Find this particular ICR by
selecting ``Currently under Review--Open for Public Comments'' or by
using the search function. OMB must receive comments no later than
October 23, 2025.

D. Regulatory Flexibility Act (RFA)

I certify that this action will not have a significant economic
impact on a substantial number of small entities under the RFA, 5
U.S.C. 601 et seq. In making this determination, EPA concludes that the
impact of concern for this action is any significant adverse economic
impact on small entities and that the Agency is certifying that this
action will not have a significant economic impact on a substantial
number of small entities because the action can relieve regulatory
burden on the small entities subject to the rule and the number of
small entities likely to be affected may be approximately 1 or less a
year as estimated in Unit VI.C of this preamble. As described in Units
I.E and VI.B, this proposal would reduce the amount of information a
manufacturer would have to provide with a voluntary request for a risk
evaluation. Details of this analysis are presented in the rule-related
ICR (Ref. 5). We have therefore concluded that this action can relieve
regulatory burden for all directly regulated small entities.

E. Unfunded Mandates Reform Act (UMRA)

This action does not contain an unfunded mandate as described in
UMRA, 2 U.S.C. 1531-1538, and does not significantly or uniquely affect
small governments. The action imposes no enforceable duty on any state,
local or tribal governments. The costs involved in this action are
imposed only on the private sector entities (manufacturers) that may
voluntarily elect to submit a request for a risk evaluation as they
would be required to comply with the proposed requirements for such
requests. Such costs are estimated not to exceed $183 million in 2023$
($100 million in 1995$ adjusted for inflation using the GDP implicit
price deflator) or more in any one year.

F. Executive Order 13132: Federalism

This action does not have federalism implications as specified in
Executive Order 13132 (64 FR 43255, August 10, 1999) because 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.

G. Executive Order 13175: Consultation and Coordination With Indian
Tribal Governments

This action does not have tribal implications as specified in
Executive Order 13175 (65 FR 67249, November 9, 2000) because it will
not have substantial direct effects on one or more Indian tribes, on
the relationship between the Federal Government and Indian tribes, or
on the distribution of power and responsibilities between the Federal
Government and Indian tribes. Thus, Executive Order 13175 does not
apply to this action.

H. Executive Order 13045: Protection of Children From Environmental
Health Risks and Safety Risks

EPA interprets Executive Order 13045 (62 FR 19885, April 23, 1997)
as applying only to regulatory actions considered significant under
section 3(f)(1) of Executive Order 12866 and that concern environmental
health or safety risks that EPA has reason to believe may
disproportionately affect children, per the definition of ``covered
regulatory action'' in section 2-202 of Executive Order 13045. Since
this action is not a ``covered regulatory action'' because it is
neither a significant regulatory action under section 3(f)(1) of
Executive Order 12866 nor an action that concerns an environmental
health risk or safety risk, Executive Order 13045 does not apply. Since
this action does not concern human health risks, EPA's Policy on
Children's Health also does not apply. This procedural rule would
address how EPA evaluates the risks of existing chemicals under TSCA,
including potential risks to children and other PESS. EPA must initiate
a rulemaking to address the unreasonable risk to human health or the
environment that the Agency may determine are presented by a chemical
substance as set forth in a TSCA risk evaluation. Although this
procedural rule itself would not directly affect the level of
protection provided to human health or the environment, EPA expects
that a rulemaking under TSCA section 6(a) could qualify as a covered
regulatory action under E.O. 13045 and therefore could be subject to
EPA's Policy on Children's Health.

[[Page 45714]]

I. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use

This action is not a ``significant energy action'' as defined in
Executive Order 13211 (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. This procedural rule would address how EPA evaluates
the risks of existing chemicals under TSCA and information requirements
for manufacturers who would submit a request that EPA conduct a risk
evaluation.

J. National Technology Transfer and Advancement Act (NTTAA)

This proposed rulemaking does not involve technical standards. As
such, NTTAA section 12(d), 15 U.S.C. 272 note, does not apply to this
action.

List of Subjects in 40 CFR Part 702

Environmental protection, Chemicals, Chemical substances, Hazardous
substances, Health and safety, Risk evaluation.

Lee Zeldin,
Administrator.
Therefore, for the reasons stated in the preamble, EPA proposes to
amend 40 CFR part 702 as follows:

PART 702--GENERAL PRACTICES AND PROCEDURES

0
1. The authority citation for part 702 continues to read as follows:

Authority: 15 U.S.C. 2605 and 2619.

Subpart B--Procedures for Chemical Substance Risk Evaluations

0
2. Amend Sec. 702.31 by revising paragraph (c) to read as follows.

Sec. 702.31 General provisions.

* * * * *
(c) Applicability.
The requirements of this part apply to all chemical substance risk
evaluations initiated pursuant to TSCA section 6(b) (15 U.S.C. 2605(b))
beginning [DATE 30 DAYS AFTER THE DATE OF PUBLICATION OF THE FINAL RULE
IN THE FEDERAL REGISTER]. For risk evaluations initiated prior to this
date, but not yet finalized, EPA will seek to apply the requirements in
this subpart to the extent practicable. These requirements shall not
apply retroactively to risk evaluations already finalized.
* * * * *
0
3. Amend Sec. 702.33 by revising the definition of ``Potentially
exposed or susceptible sub-population'' and adding a definition of
``Weight of the scientific evidence'' to read as follows:

Sec. 702.33 Definitions.

* * * * *
Potentially exposed or susceptible subpopulation means a group of
individuals within the general population identified by EPA who, due to
either greater susceptibility or greater exposure, may be at greater
risk than the general population of adverse health effects from
exposure to a chemical substance or mixture, such as infants, children,
pregnant women, workers, or the elderly.
* * * * *
Weight of scientific evidence means an approach to scientific
evaluation in which each piece of relevant information is considered
based on its quality and relevance, and then transparently integrated
with other relevant information to inform the scientific evaluation
prior to making a judgment about the scientific evaluation. Quality and
relevance determinations, at a minimum, should include consideration of
study design, fitness for purpose, replicability, peer review, and
transparency and reliability of data.
0
4. Amend Sec. 702.37 by revising and republishing paragraphs (a)(3)
and (4) to read as follows:

Sec. 702.37 Evaluation requirements.

* * * * *
(a) Considerations.
* * * * *
(3) EPA will ensure that all supporting analyses and components of
the risk evaluation are suitable for their intended purpose, and
tailored to the problems and decision at hand, in order to inform the
development of technically sound determinations as to whether the
chemical substance presents an unreasonable risk of injury to health or
the environment under each of the conditions of use, based on the
weight of the scientific evidence. A fit-for-purpose approach may
result in varying types and levels of analysis and supporting
information for certain conditions of use, consistent with paragraph
(b) of this section. The extent to which EPA will refine its
evaluations for one or more conditions of use in any risk evaluation
will vary as necessary to determine whether the chemical substance
presents an unreasonable risk of injury to health or the environment
under that condition of use.
(4) EPA will evaluate chemical substances that are metals or metal
compounds in accordance with 15 U.S.C. 2605(b)(2)(E).
* * * * *
0
5. Amend Sec. 702.39 by removing paragraphs (d)(8) and (9), and
revising paragraphs (d)(7) and (f) to read as follows:

Sec. 702.39 Components of risk evaluation.

* * * * *
(d) Exposure assessment.
* * * * *
(7) EPA will describe whether aggregate or sentinel exposures under
the conditions of use were considered and the basis for their
consideration.
* * * * *
(f) Risk determination.
(1) As part of the risk evaluation, EPA will determine whether the
chemical substance presents an unreasonable risk of injury to health or
the environment under the conditions of use by making separate risk
determinations for each condition of use within the scope of the risk
evaluation, either in a single decision document or in multiple
decision documents.
(2) In determining whether unreasonable risk is presented, EPA's
consideration of occupational exposure scenarios will take into account
reasonably available information on the implementation and use of
occupational exposure control measures such as engineering and
administrative controls and personal protective equipment.
(3) In determining whether unreasonable risk is presented, EPA will
consider the following risk-related factors included in the risk
evaluation, as outlined in 40 CFR 702.39 (c), (d), and (e), and any
other risk-related factors that are relevant:
(i) The severity of the hazard (e.g., the nature of the hazard and
irreversibility of the hazard);
(ii) Exposure-related considerations (e.g., duration, intensity,
and frequency of exposure);
(iii) The population exposed (including any potentially exposed or
susceptible subpopulations (PESS)); and
(iv) The confidence in the information used to inform the hazard
and exposure values, including an evaluation of the strengths,
limitations, and uncertainties associated with the information used to
inform the risk estimate and the risk characterization.
0
6. Amend Sec. 702.43 by revising and republishing paragraphs (e), (f),
and (g) to read as follows:

Sec. 702.43 Risk evaluation actions and timeframes.

* * * * *
(e) Final determination of unreasonable risk. Upon a

[[Page 45715]]

determination by EPA pursuant to Sec. 702.39(f) that one or more
conditions of use of a chemical substance present an unreasonable risk
of injury to health or the environment, EPA will initiate action as
required pursuant to 15 U.S.C. 2065(a).
(f) Final determination of no unreasonable risk. A determination by
EPA pursuant to Sec. 702.39(f) that a condition of use of a chemical
substance does not present an unreasonable risk of injury to health or
the environment will be issued by order and considered to be a final
Agency action, effective on the date of issuance of the order.
(g) Substantive revisions to scope documents and risk evaluations.
The circumstances under which EPA will undertake substantive revisions
to scope and risk evaluation documents are as follows:
(1) Draft documents.
To the extent there are changes to a draft scope or draft risk
evaluation, EPA will describe such changes in the final document.
(2) Final scope.
To the extent there are changes to the scope of the risk evaluation
after publication of the final scope document, EPA will describe such
changes in the draft risk evaluation, or, where appropriate and prior
to the issuance of a draft risk evaluation, may make relevant
information publicly available in the docket and publish a notice of
availability of that information in the Federal Register.
(3) Final risk evaluations.
Where EPA supplements or revises, in whole or in part, a final risk
evaluation, EPA will follow the procedures in this section including
publication of a new draft and final risk evaluation and solicitation
of public comment in accordance with Sec. Sec. 702.43(c) and (d), and
peer review, as appropriate, in accordance with Sec. 702.41.
0
7. Amend Sec. 702.45 by revising and republishing to read as follows:

Sec. 702.45 Submission of manufacturer requests for risk evaluations.

(a) General provisions.
(1) One or more manufacturers of a chemical substance may request
that EPA conduct a risk evaluation on a chemical substance.
(2) Such requests must comply with all the requirements,
procedures, and criteria in this section.
(3) In determining whether there is sufficient information to
support a manufacturer-requested risk evaluation, EPA expects to apply
the same standard as it would for EPA-initiated risk evaluations,
including but not limited to the considerations and requirements in
Sec. 702.37.
(4) EPA will not expedite or otherwise provide special treatment to
a manufacturer-requested risk evaluation pursuant to 15 U.S.C.
2605(b)(4)(E)(ii).
(5) Once initiated in accordance with paragraph (e)(9) of this
section, EPA will conduct manufacturer-requested risk evaluations
following the procedures in Sec. Sec. 702.37 through 702.43 and
Sec. Sec. 702.47 through 702.49 of this subpart.
(6) For purposes of this section, information that is ``known to or
reasonably ascertainable by'' the requesting manufacturer(s) would
include all information in the requesting manufacturer's possession or
control, plus all information that a reasonable person similarly
situated might be expected to possess, control, or know.
(7) In the event that a group of manufacturers of a chemical
substance submit a request for risk evaluation under this section, the
term ``requesting manufacturer'' in this section applies to all
manufacturers in the group. EPA will otherwise coordinate with the
primary contact named in the request for purposes of communication,
payment of fees, and other actions as needed.
(b) Method for submission.
All manufacturer-requested risk evaluations under this subpart must
be submitted via the EPA Central Data Exchange (CDX) found at <a href="https://cdx.epa.gov">https://cdx.epa.gov</a>.
(c) Content of request.
Requests must include all of the following information:
(1) Name, mailing address, and contact information of the entity
(or entities) submitting the request. If more than one manufacturer
submits the request, all individual manufacturers must provide their
contact information.
(2) The chemical identity of the chemical substance that is the
subject of the request. At a minimum, this includes: all known names of
the chemical substance, including common or trades names, CAS number,
and molecular structure of the chemical substance.
(3) For requests pertaining to a category of chemical substances,
an explanation of why the category is appropriate under 15 U.S.C.
2625(c). EPA will determine whether the category is appropriate for
risk evaluation as part of reviewing the request in paragraph (e) of
this section.
(4) A description of the circumstances for which the manufacturer
is requesting that EPA conduct a risk evaluation, all information known
to or reasonably ascertainable by the requesting manufacturer that
supports the identification of the requested circumstances, and a
rationale for why the requested circumstances constitute conditions of
use under 702.33.
(5) All information known to or reasonably ascertainable by the
requesting manufacturer on the health and environmental hazard(s) of
the chemical substance, human and environmental exposure(s), and
exposed population(s), including but not limited to:
(i) The chemical substance's exposure potential, including
occupational, general population and consumer exposures, and facility
release information;
(ii) The chemical substance's hazard potential, including all
potential environmental and human health hazards;
(iii) The chemical substance's physical and chemical properties;
(iv) The chemical substance's fate and transport properties
including persistence and bioaccumulation;
(v) Industrial and commercial locations where the chemical is used
or stored;
(vi) Whether there is any storage of the chemical substance near
significant sources of drinking water, including the storage facility
location and the nearby drinking water source(s);
(vii) Consumer products containing the chemical;
(viii) The chemical substance's production volume or significant
changes in production volume; and
(ix) Any other information relevant to the hazards, exposures and/
or risks of the chemical substance.
(6) Where information described in paragraph (

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Indexed from Federal Register on September 23, 2025.

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