U.S. Environmental Protection Agency

Perchloroethylene (PCE); Revision to Toxic Substances Control Act

(TSCA) Risk Determination

EPA-HQ-OPPT-2016-0732

Response to Public Comments

December 2022


-------
This page intentionally left blank.


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

Table of Contents

Acronyms and Abbreviations	iii

Introduction	iv

Table 1: Index of Comment Submissions Sorted by Submission Number	v

Section 1 - General support for the draft revision to the risk determination	1

Section 2 - General opposition to the draft revision to the unreasonable risk determination	1

Section 3 - Requests for an extension of the comment period	2

Section 4 - Legal issues	2

Section 4.1 - Statutory authority and TSCA section 26	2

Section 4.2 - Process of revising the risk determination	5

Section 5 - Revisions to the risk determination	7

Section 5.1 - Whole chemical approach vs. individual condition of use (COU)	7

Section 5.1.1 - Support for the whole chemical approach	7

Section 5.1.2- Opposition to the whole chemical approach	9

Section 5.1.3 - Inconsistency with TSCA and Risk Evaluation Rule	11

Section 5.1.4- Other comments on the whole chemical approach	19

Section 5.2 - Baseline scenario that does not assume PPE or other mitigation measures in place	20

Section 5.2.1 - Support for EPA's intention not to assume PPE or other mitigation measures are in
place	20

Section 5.2.2 - Opposition to EPA's intention not to assume PPE or other mitigation measures are in
place	22

Section 5.2.3 - OSHA requirements and industry best practices	29

Section 5.2.4 - Other comments regarding determination of unreasonable risk not assuming PPE or
other mitigations measures are in place	30

Section 5.2.5 - Permissible exposure limits (PELs)	33

Section 5.2.6 - Other comments on OSHA requirements or best practices	34

Section 6 - Unreasonable risk determination	36

Section 7 - Conditions of use that drive the unreasonable risk determination	37

Section 7.1 - Processing (including recycling)	37

Section 7.2 - Industrial and commercial use	38

Section 8 - Comments regarding conditions of use that do not drive the unreasonable risk determination
	39

Section 9 - Comments regarding EPA's withdrawal of the associated orders	41

Section 10 - Comments on EPA's screening approach to assess risks from air and water pathways	42

Section 11 - Other comments related to the draft revision of the risk determination	43

l


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

Previously submitted comments	43

Risk Management	43

Other	44

Section 12 - Comments on potential revisions to other risk determinations for the first ten chemicals .... 46

li


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

Acronyms and Abbreviations

APF

Assigned protection factor

COU

Condition of use

EPA

U.S. Environmental Protection Agency

HBCD

Cyclic aliphatic bromide cluster

NAS

National Academy of Sciences

NIOSH

U.S. National Institute for Occupational Safety and Health

ONU

Occupational non-user

OSHA

U.S. Occupational Safety and Health Administration

OSH Act

Occupational Safety and Health Act of 1970

PCE

Perchloroethylene

PEL

Permissible exposure limit

PESS

Potentially exposed or susceptible subpopulation

PF

Protection factor

PPE

Personal protective equipment

PV29

Colour Index Pigment Violet 29

SACC

Scientific Advisory Committee on Chemicals

TSCA

Toxic Substances Control Act

U.S.

United States

u.s.c.

United States Code

111


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

Introduction

On June 30, 2022, the U.S. Environmental Protection Agency (EPA) published a notice of
availability and request for comment on a draft revision to the Toxic Substances Control Act
(TSCA) Risk Determination for Perchloroethylene (PCE). In the notice, EPA announced that
public comments would be accepted until August 1, 2022.

EPA received a total of 20 public comments (as well as one submission correcting a previously
submitted comment) and determined that all comments are unique and responsive to the request
for comments. Table 1, Index of Comment Submissions Sorted by Submission Number,
identifies the commenter name and the comment number for the 20 unique submissions included
in this summary.

The comment summaries and responses that follow are organized into issue topic areas, as
indicated in the table of contents.

IV


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

Table 1: Index of Comment Submissions Sorted by Submission Number

Submission Number

Organization

EP A-HO-OPPT-2016-0732-0118

Shatory Blackmon

EPA-HO-OPPT-2016-0732-0119

Louisiana Chemical Association

EP A-HO-OPPT-2016-0732-0120

American Chemistry Council

EP A-HO-OPPT-2016-0732-0121

American Federation of Labor and Congress of Industrial
Organizations

EP A-HO-OPPT-2016-0732-0122

American Fuel & Petrochemical Manufacturers and
American Petroleum Institute

EP A-HO-OPPT-2016-0732-0123

Chemical Users Coalition

EP A-HO-OPPT-2016-0732-0124

City of San Francisco et al.

EP A-HO-OPPT-2016-0732-0125

Environmental Defense Fund

EP A-HO-OPPT-2016-0732-0126

Environmental Protection Network

EP A-HO-OPPT-2016-0732-0127

Halogenated Solvents Industry Alliance, Inc.

EP A-HO-OPPT-2016-0732-0128

Halogenated Solvents Industry Alliance, Inc.

EP A-HO-OPPT-2016-0732-0129

Household & Commercial Products Association

EP A-HO-OPPT-2016-0732-013 0

Louisiana Chemical Association

EP A-HO-OPPT-2016-0732-0131

National Association of Chemical Distributors

EP A-HO-OPPT-2016-0732-0132

Safer Chemicals Healthy Families et al.

EP A-HO-OPPT-2016-0732-013 3

Spirit AeroSystems, Inc.

EP A-HO-OPPT-2016-0732-0134

The Chemours Company

EP A-HO-OPPT-2016-0732-013 5

Alliance for Automotive Innovation

EP A-HO-OPPT-2016-0732-013 6

U.S. Chamber of Commerce

EP A-HO-OPPT-2016-0732-013 7

Alliance for Responsible Atmospheric Policy

EP A-HO-OPPT-2016-0732-013 8

Environmental Protection Network

v


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

Section 1 - General support for the draft revision to the risk determination

Comments that provided general support also provided more substantive comments that are
summarized in other portions of the summary report.

Several non-governmental environmental and health advocacy organizations (0132, 0125)
provided general support for the revised PCE unreasonable risk determination. The organizations
explained that they favored the change to a whole chemical approach because, among other
things, the whole chemical approach better aligns with the goals of TSCA and the 2016
Lautenberg amendments. The organizations stated that by removing the assumptions that
workers always are provided and always properly wear personal protective equipment (PPE),
EPA can adopt risk management approaches that better protect not only workers but also other
potentially exposed or susceptible subpopulations (PESS). Similarly, a comment submitted by
several state and local government agencies and organizations (0124) expressed strong support
for EPA's new path forward for TSCA risk evaluations. The commenter encouraged EPA to
apply a whole-of-government approach to chemical regulation, as it has begun to do with lead
and polyfluoroalkyl substances, and continue to withdraw past determinations of no
unreasonable risk for specific conditions of use in the first ten risk evaluations.

An advocacy organization (0126, 0138) stated that, despite concerns about a number of issues
involved in the risk evaluation of PCE, they agree with the reasoning and conclusions drawn by
EPA in the June 2022 draft revision to the TSCA risk determination of PCE.

EPA RESPONSE:

EPA appreciates the support for the revised unreasonable risk determination.

Section 2 - General opposition to the draft revision to the unreasonable risk determination

The comment that provided general opposition also provided more substantive comments that
are summarized in other portions of the summary report.

An industry trade organization (0135) stated that the revisions to the risk determination will
change public interpretations of risk, have unwarranted impacts on future risk management
decision-making, and cause unintended regulatory impacts on articles (including replacement
parts) containing certain substances.

EPA RESPONSE:

EPA would like to reiterate that this action pertains specifically to the unreasonable risk
determination for PCE. While EPA intends to consider and may take additional similar actions
on other of the first ten chemical substances with completed TSCA section 6 risk evaluations,
EPA is taking a chemical-specific approach to revising the risk determination of this risk
evaluation and is incorporating new policy direction in a surgical manner, while being mindful of
Congressional direction on the need to complete risk evaluations and move toward any
associated risk management activities. Regarding public communication and interpretation of
risk, EPA has emphasized, in both the Federal Register Notice and the final revised unreasonable

1


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

risk determination, the conditions of use that drive the unreasonable risk for PCE, as well as
listing the condition of use that does not.

With respect to impacts from this revised unreasonable risk determination on risk management
of PCE, EPA will propose a regulatory action with requirements under TSCA section 6(a) to the
extent necessary so that PCE no longer presents unreasonable risk. The public will have an
opportunity to comment on the proposed regulatory action, and EPA will consider such public
comments and any additional information before finalizing the rulemaking. As a result, EPA
expects that impacts to PCE-containing articles, including consideration of replacement parts and
articles under TSCA section 6(c)(2)(D) and (E), will be considered during rulemaking. EPA
encourages the commenter to submit specific comments about regulatory impacts on PCE-
containing articles during the future public comment period for the PCE risk management rule.

Section 3 - Requests for an extension of the comment period

An industry trade organization (0119) requested an extension of the comment period for no less
than 30 additional days. The commenter stated that the extension would enable their members to
spend sufficient time identifying all potential aspects of the risk determination about which they
wish to submit comments to EPA. The extension would also assist EPA in ensuring that the
Agency obtains a well-balanced collection of comments from all interested parties.

EPA RESPONSE:

EPA received the extension request and determined that extending the comment period was not
warranted. Requester did submit a substantive comment in the time period provided.

Section 4 - Legal issues

Comments discussing legal issues with the whole chemical approach, including its consistency
with TSCA, are discussed in Section 5.1.

Section 4.1 - Statutory authority and TSCA section 26

A few commenters provided feedback on EPA's statutory authority under TSCA. Three industry
trade organizations or coalitions (0120, 0131, 0137) stated that EPA's proposed approach does
not comply with TSCA section 26 and section 6 requirements that risk evaluations be consistent
with best available science and based on the weight of the scientific evidence. One of the
commenters (0120) added that the legislative record for the TSCA amendments also does not
support EPA's new policy direction.

An industry trade organization (0131) provided its view that EPA's final risk evaluation for PCE
is predicated on a systematic review method that does not meet the scientific standards under
TSCA section 26. The industry trade organization discussed how, in May 2018, EPA released a
document titled "Application of Systematic Review in TSCA Risk Evaluations" (2018 SR
Document) and stated that, rather than incorporating and adapting existing methodologies that
represented the best available science at the time, the use of the approach in the 2018 SR
Document led to pervasive problems in the first ten risk evaluations. The commenter stated that

2


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

EPA's updates do not resolve the issue that the systematic review method underlying PCE's final
risk evaluation may have contravened TSCA section 26. The industry trade organization stated
that it does not agree that EPA may implement the proposed changes without amending the
scientific analysis in the final risk evaluation for PCE, providing its view that EPA must justify
these changes with additional analysis. The commenter stated the view that the final risk
evaluation for PCE was of low quality. The industry trade organization stated its view that EPA
conduct a robust systematic review and update the risk evaluation as warranted based on the
review in order to satisfy the requirements of TSCA sections 26(h) and (i).

An industry trade organization (0128) provided a detailed discussion of the Cavalleri et al.
(1994) study, as well as EPA's analysis and dose-response assessment of the study. The
commenter provided its view that EPA's analysis and assessment was flawed and must be
corrected. The industry trade organization also discussed the calculation of the Inhalation Unit
Risk for PCE in the risk evaluation. The commenter stated that EPA's evaluation of the mouse
liver tumor mode-of-action was inaccurate and did not represent the best available science. The
commenter stated its view that the weight of the scientific evidence supports a peroxisome-
proliferator activated receptor alpha mode-of-action for PCE-induced mouse liver tumors; thus,
they are not relevant to humans. The industry trade organization concluded by stating that the
underlying risk evaluation for PCE does not comply with TSCA section 6(b) risk evaluation
requirements, including accounting for exposure under the conditions of use, describing the
weight of the scientific evidence for the identified hazard and exposure, using scientific
information employed in a manner consistent with the best available science, and considering the
extent of independent verification or peer review of the information. The commenter stated its
view that to maintain the credibility of its regulatory efforts under TSCA, it is imperative that
EPA build upon the available information to construct a more realistic risk evaluation before
proceeding with rulemaking.

A chemical manufacturer (0134) and an industry trade organization (0128) stated that EPA did
not use best available science for the PCE risk determination in its dermal risk assessment
approach. The industry trade organization commented that recognition of standard work
practices and reliance on reasonable and realistic exposure data are critical to meet the statutory
requirements of TSCA, as well as the "objectivity" criterion of the Information Quality Act and
provided its view that EPA's reliance on hypothetical assumptions for modeling of the amount of
PCE that is absorbed by workers from dermal contact cannot be justified. The commenter stated
its view that EPA's use of unrealistic dermal exposure assumptions has led to erroneous
conclusions regarding the health risks to workers using PCE in closed systems. Similarly, the
chemical manufacturer (0134) requested that EPA reconsider the dermal risk assessment
approach for PCE to reflect modern industry risk management measures and accurately reflect
potential exposure for the final risk evaluation. The commenter included with their comment an
attachment (February 2021 meeting slides it previously presented to EPA).

An industry trade organization (0122) stated that EPA's final risk evaluation for PCE did not
take into account the unique conditions of use in petroleum refineries; rather, it generalized the
use as a processing aid and not specifically as a catalyst regenerator. The commenter noted that

3


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

petroleum refiners have requested that EPA reopen the risk evaluation to incorporate the actual
frequency and duration under the conditions of use and rerun the exposure models, but EPA has
thus far expressed resistance to reopening the exposure assessment portion of the risk evaluation.
The commenter stated that in Chemical Manufacturers Association, et al. v. U.S. Environmental
Protection Agency, the court found that EPA could not use hypothetical exposures to justify a
test rule under TSCA section 4. The commenter stated their view that "EPA's hypothetical use
scenario for PCE at petroleum refineries would never occur in the real world, has no relation to
actual risk, and ignores existing OSHA regulations, standard industrial hygiene practices, and
standard operating procedures at refineries," and asserted that EPA must therefore modify its
underlying assumptions before using the finalized risk evaluation as justification for new risk
management measures.

EPA RESPONSE:

The final revised unreasonable risk determination for PCE is based on the peer reviewed risk
characterization in the December 2020 PCE Risk Evaluation, based on reasonably available
information pursuant to TSCA section 26(k) and 40 CFR 702.33, and developed in accordance
with TSCA section 26(h) and (i) to make decisions under TSCA section 6 in a manner consistent
with the best available science and based on the weight of scientific evidence. While EPA has
undertaken efforts to refine its 2018 approach to systematic review by developing a draft
systematic review protocol that has undergone review by NASEM, the draft protocol is not a
final document. EPA expects to use chemical-specific protocols in the future that are reflective
of what the Agency learned in this and the Science Advisory Committee on Chemicals (SACC)
peer review process and public comment. EPA does not expect to apply adjustments
retroactively; retroactive application would lead to further delays in completing the risk
evaluations for the first ten substances contrary to Congressional intent. Thus, EPA maintains
that the December 2020 PCE Risk Evaluation meets TSCA section 26(h) requirements. In
response to comments asserting that EPA's risk evaluation does not meet the standards of TSCA
section 26 (0128, 0131) or that specific analyses are flawed or inaccurate (0128), EPA
emphasizes that the Agency is not amending the underlying scientific analysis. EPA also views
the peer reviewed hazard and exposure assessments and associated risk characterization as robust
and upholding the standards of best available science and weight of the scientific evidence per
TSCA sections 26(h) and (i). The policy changes described in the Federal Register Notice
announcing the availability of the draft revised risk determination for PCE do not amend or
impact the underlying data and analysis presented in the risk characterization of the December
2020 PCE Risk Evaluation. The policy changes do not impact the characterization of risk
estimates by condition of use (summarized in Section 4 of the final risk evaluation), or the
occupational exposures to workers and ONUs (summarized in Section 2.4 of the final risk
evaluation). Similarly, regarding the commenter describing the unique conditions of petroleum
refineries (0122), and asserting that EPA should reopen the exposure component of the risk
evaluation, EPA notes that the 1988 case cited by the commenter relates to a test rule under
TSCA section 4, rather than a risk evaluation under TSCA section 6(b) (as amended in 2016).
See ChemicalMfrs. Ass'n v. EPA, 859 F.2d 977 (D.C. Cir. 1988) (upholding EPA's
interpretation of TSCA section 4 as empowering the Agency to issue a test rule on health

4


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

grounds where it finds a more-than-theoretical basis for suspecting that the chemical substance
presents an unreasonable risk of injury to health, and where the existence of exposure is inferred
from the circumstances under which the substance is manufactured and used rather than
documented by direct evidence). EPA's occupational exposure scenarios and their applications to
the conditions of use of PCE were subject to public comment and peer review; as described
earlier, the revisions to the risk determination do not impact the underlying models used in the
risk evaluation. Further discussion of EPA's consideration of workplace practices and
implementation of OSHA-compliant standard operating procedures is in section 5.2 of this
document.

In response to the commenter's assertion about the legislative record to support EPA's new
policy direction, Congress was clear that TSCA provides EPA broad authority to regulate
existing chemicals and delegated to EPA responsibility for implementing and overseeing a
process to conduct risk evaluations to "determine whether a chemical substance presents an
unreasonable risk of injury to health or the environment.. .under the conditions of use." See, e.g.,
S. REP. 114-67 (2015); 15 U.S.C. 2605(b)(4)(A). Fully consistent with that delegation, EPA
expects that its interpretation of 40 CFR 702.47 will provide greater flexibility in the Agency's
ability to evaluate and manage unreasonable risk from individual chemical substances. Further
support for the whole chemical approach is in section 5.1.1.

In response to the information provided regarding modern industry risk management measures
(0134), EPA appreciates this information and intends to consider current best workplace
practices as it develops TSCA section 6(a) risk management action to address the unreasonable
risk determined in the PCE risk evaluation; for instance, to help inform EPA's assessment of the
feasibility and efficacy of different risk management options.

Section 4.2 - Process of revising the risk determination

EPA received comments related to the process of revising the risk determination. An industry
trade organization (0120) requested that EPA withdraw the draft revision to the risk
determination and provide an explanation for the proposed changes and additional public
comment opportunity before applying the changes. Furthermore, the commenter believes the
whole chemical approach lacks clarity and will have substantial impacts on future chemical
analysis.

Similarly, another industry trade organization (0131) commented that EPA did not adequately
support its decision to apply the whole chemical approach and not to assume workers' use of
PPE in EPA's draft revision to the risk determination for cyclic aliphatic bromide cluster
(HBCD). The commenter added that EPA also did not adequately respond to some HBCD
commenters' concerns raised in the HBCD docket. The commenter stated its view that the PCE
draft revision lacks support in the same way as the commenter indicated that the HBCD revision
did.

An advocacy group (0125) discussed at length that the Kisor case cannot be applied to question
the viability of the whole chemical approach as the Supreme Court in this case reaffirmed the

5


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

long-standing principle that courts must generally defer to agencies' reasonable interpretations of
their own ambiguous regulations, and that the list of considerations provided by the Court in
Kisor favors a reviewing court granting deference to EPA on its whole chemical approach.

EPA RESPONSE:

The revised unreasonable risk determination for PCE is based on the peer reviewed risk
characterization of the December 2020 risk evaluation, which was developed according to the
TSCA section 26(h) requirement to make science-driven decisions, consistent with best available
science, and in accordance with the TSCA section 26(i) requirement to make decisions based on
the weight of scientific evidence. Changing the risk determination to a whole chemical approach
does not impact the underlying data and analysis presented in the risk characterization of the risk
evaluation.

The draft revised unreasonable risk determination for PCE was published in June 2022 along
with the Federal Register Notice explaining the whole chemical approach to the PCE
unreasonable risk determination, and why EPA believes that a whole chemical approach to PCE
better aligns with TSCA's objective of protecting health and the environment. The draft revised
unreasonable risk determination also explained why EPA believes that not assuming the use of
PPE or other mitigating measures as part of the risk evaluation better aligns with TSCA. EPA
understands that there could be occupational safety protections in place at workplace locations;
however, not assuming use of PPE reflects EPA's recognition that unreasonable risk may exist
for subpopulations of workers that may be highly exposed because they are not covered by
Occupational Safety and Health Administration (OSHA) standards, or their employers are out of
compliance with OSHA standards, or because many of OSHA's chemical-specific permissible
exposure limits largely adopted in the 1970's are—as noted by OSHA—"outdated and
inadequate for ensuring protection of worker health,"1 or because the OSHA PEL alone may be
inadequate to protect worker health, or because EPA finds unreasonable risk for purposes of
TSCA notwithstanding OSHA requirements. EPA provided notice and an opportunity for public
comment on the draft revised risk determination for PCE and the approach described in the
Federal Register Notice. Further discussion of EPA's consideration of PPE use and OSHA
standards are in section 5.2 of this document.

EPA has responded to the comments received on the draft revised unreasonable risk
determination for HBCD (EPA-HQ-OPPT-2019-0237-0124)). In that document for HBCD and
below, for PCE, EPA provides an expanded explanation of why the whole chemical approach to
PCE better aligns with TSCA objectives (including listing of the conditions of use that do and do
not drive the unreasonable risk for PCE as a whole chemical substance) and the rationale behind
not assuming the use of PPE in the PCE unreasonable risk determination.

With respect to EPA's approach to changing the PCE risk determination, the revised Section 5 of
the PCE Risk Evaluation describes the determination of unreasonable risk of PCE as a "whole
chemical substance," details how all but one of the 61 conditions of use EPA evaluated drive the

1 As noted on Occupational Safety and Health Administration. Permissible Exposure Limits - Annotated Tables.
Accessed June 13, 2022. https://www.osha.gov/an.notated-peis.

6


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

unreasonable risk determination, and explains the change in approach regarding assuming use of
PPE by workers. As mentioned, the whole chemical risk determination approach does not impact
the underlying data and analysis presented in the risk characterization of the 2020 PCE Risk
Evaluation. The risk evaluation already includes exposure analysis with and without PPE (see
Table 4-125 in the risk evaluation). EPA has made no changes to this scientific analysis. The
Agency believes that the revised risk determination is sufficiently clear that it supersedes any
conflicting statements in the December 2020 risk evaluation that it is neither necessary nor an
appropriate use of resources to reissue the entire risk evaluation.

EPA appreciates comments concerning the application of Kisor v. Wilkie, 139 S. Ct. 2400
(2019), to EPA's draft revised unreasonable risk determination for PCE. Similar to the
commenter's view, EPA maintains that its interpretation of 40 CFR 702.47 as permitting the
issuance of either COU-specific or whole chemical risk determinations is a reasonable
interpretation of that regulation and would be entitled to Auer deference (see Auer v. Robbins,
117 S.Ct. 905 (1997)) when using the multifactor test set forth in Kisor.

Section 5 - Revisions to the risk determination

Section 5.1 - Whole chemical approach vs. individual condition of use (COU)

Section 5.1.1 - Support for the whole chemical approach

Several non-governmental environmental and health advocacy organizations (0125, 0132) and a
union (0121) in expressing support for the whole chemical approach for PCE, stated their view
that the approach is consistent with the language and purpose of TSCA. One advocacy
organization (0132) stated that TSCA requires whole chemical determinations of unreasonable
risk to satisfy the mandate to integrate and assess available information on hazards and exposures
from the COU, especially in cases of PESS, multiple routes of exposure, and combined risk to
exposed populations across the chemical's COUs and life-cycle stages. The commenter added
that a whole chemical unreasonable risk is also more efficient and straightforward than using a
COU-specific approach, reasoning that EPA both could choose not to regulate conditions of use
the Agency finds to be safe and could issue clear statements with respect to the safe conditions of
use for the chemical at issue. The advocacy organizations (0125, 0132) commented that TSCA
unambiguously mandates EPA to conduct a whole chemical risk determination as the language
of the statute referencing decision-making for a chemical substance dictates that EPA cannot
segment its determination into separate findings of unreasonable risk for some conditions of use
and no unreasonable risk for others. One of the advocacy groups (0125) stated its view that EPA
should take a whole chemical approach for all chemicals' future risk determination to fulfill
TSCA's mandate that EPA identify the full risk posed by each chemical.

A union (0121) stated that a whole chemical approach would ensure that all workers exposed to
unreasonable risks from PCE can be provided equivalent protections under TSCA.

Some commenters (0125, 0132) stated that EPA is correct to rely on the 2019 Ninth Circuit's
interpretation of the governing regulation in Safer Chemicals v. EPA to conduct a whole
chemical risk determination.

7


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

EPA RESPONSE:

EPA appreciates the comments in support of the whole chemical approach. As EPA explained in
the Federal Register Notice announcing the availability of the draft revised risk determination for
PCE, notwithstanding EPA's choice to issue COU-specific risk determinations to date, EPA
interprets its risk evaluation regulation to also allow the Agency to issue whole chemical risk
determinations. Either approach is permissible under the regulation, and the Ninth Circuit Court
of Appeals also recognized the ambiguity of the regulation on this point in Safer Chemicals et al.
v. EPA (943, F.3d 397 (9th Cir. 2019). EPA plans to consider the appropriate approach for each
chemical substance risk evaluation on a case-by-case basis, taking into account considerations
relevant to the specific chemical substance in light of the Agency's obligations under TSCA.
EPA expects that this case-by-case approach will provide greater flexibility to evaluate and
manage unreasonable risk from individual chemical substances as required under TSCA. EPA
anticipates that this flexibility will better serve TSCA's objectives by helping ensure that EPA is
best positioned to present, and initiate risk management to address, chemical-specific
unreasonable risk determinations. EPA believes this is a reasonable approach under TSCA and
the Agency's implementing regulations.

For PCE, the whole chemical approach is appropriate because there are benchmark exceedances
for a substantial number of conditions of use (60 of the 61 evaluated) spanning across the
chemical lifecycle-from manufacturing (including import), processing, industrial and
commercial use, consumer use, and disposal-for workers, occupational non-users (ONUs),
consumers, and bystanders. In addition to the breadth of identified risk, EPA also considered the
severity of the health effects associated with PCE exposures, including cancer, chronic non-
cancer, and acute effects. Because these chemical-specific health hazards and exposures cut
across the conditions of use within the scope of the risk evaluation, a substantial amount of
conditions of use drive the unreasonable risk, and the Agency is better positioned to achieve its
TSCA objectives for PCE when issuing a whole chemical determination for PCE, it is
appropriate for the Agency to make a determination that the whole chemical presents an
unreasonable risk.

EPA agrees that a whole chemical approach will help ensure the public, including workers, is
protected from unreasonable risks from chemicals in a way that is supported by science and the
law, and appreciates the commenter's support.

In response to the comment that risk management activities could be tailored to individual
conditions of use, EPA notes that, in the final revised risk determination, EPA identifies which
conditions of use drive the unreasonable risk of PCE. Consistent with the statutory requirements
of TSCA section 6(a), EPA would propose risk management actions to the extent necessary so
that PCE no longer presents an unreasonable risk. Therefore, it is expected that EPA's risk
management actions will focus on the conditions of use that drive the unreasonable risk.
However, it should be noted that, under TSCA section 6(a), EPA is not limited to regulating the
specific activities found to drive unreasonable risk and may select from among a suite of risk
management requirements in section 6(a) related to manufacture (including import), processing,
distribution in commerce, commercial use, and disposal as part of its regulatory options to

8


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

address the unreasonable risk. For example, EPA may regulate upstream activities (e.g.,
processing, distribution in commerce) in order to address downstream activities driving
unreasonable risk (e.g., consumer use) even if the upstream activities are do not drive the
unreasonable risk.

Section 5.1.2 - Opposition to the whole chemical approach

Some commenters, including industry trade associations (0135, 0120, 0123, 0130, 0127),
opposed the whole chemical approach for unreasonable risk determination. Their comments
included:

•	EPA has not supported its claim that its whole chemical approach to risk determinations
is science-based and has provided no science-based support for why a majority of COUs
should trigger a whole chemical unreasonable risk determination (0120, 0127).

•	EPA did not provide examples of how the whole chemical approach would provide
administrative flexibility and did not adequately answer comments regarding this subject
in the HBCD and PV29 draft revised risk determinations; thus, the proposed change lacks
sufficient rationale. (0120).

•	EPA has provided no principles or criteria by which it will determine when to take a
whole chemical approach in risk determinations (0127).

•	The whole chemical approach would have substantial unintended consequences,
including prolonged uncertainty for the regulated community, non-science-based market
impacts, and the continued use of resources to research uses which pose no risk (0120,
0135).

•	The whole chemical approach would result in a negative finding on uses that may not
have an unreasonable risk, regrettable substitutions as manufacturers seek to quickly
implement functional alternatives, and public confusion, as the public will not know
which uses are safe and which pose risk (0120, 0135).

•	EPA's application of a whole chemical approach could ban the use of PCE in aircraft
fabrication, with safety detriments to the flying public (0133).

Another industry trade organization (0123) stated its view that EPA should continue to make
COU-specific risk determinations for PCE and other chemical substances, because such an
approach is grounded in the statute and regulations and supported by sound science. This
commenter said that using the whole chemical approach fails to provide the clarity of EPA's
decision-making regarding the risks presented and not presented by PCE that the COU-specific
determinations in the December 2020 risk evaluation provided, and would result in skewed
understandings of the risk of chemical substances. A different industry trade organization (0130)
commented that risk evaluations and determinations must be made on a COU-specific basis,
citing an EPA response to comment (EPA-HQ-OPPT-2016-0732-0115) as acknowledging that
risk evaluations should be made on a COU-specific basis.

9


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

This industry trade organization (0123) also said that EPA's policy changes implemented in the
revised unreasonable risk determination for PCE may lead to unwarranted impacts on importers
of articles containing a chemical substance for which EPA conducts a risk evaluation. The
commenter noted that by taking a whole chemical approach, EPA may influence a public
perception that these COUs present an unreasonable risk. Also, the whole chemical approach
may increase the likelihood that EPA will regulate the use of PCE in articles that were previously
deemed to not present an unreasonable risk, specifically because EPA views TSCA section 6(a)
as permitting EPA to regulate upstream activities in order to address downstream activities
driving unreasonable risk even if those upstream activities do not drive the unreasonable risk.
Finally, an industry trade organization (0135) commented that applying a COU-specific
approach allows stakeholders and EPA to focus more efficiently on uses that in fact pose
unreasonable risks.

EPA RESPONSE:

As EPA explained in the Federal Register Notice announcing the availability of the draft revised
risk determination for PCE, EPA acknowledges a lack of specificity in the statute and
inconsistency in the regulations with respect to the presentation of risk determinations in TSCA
section 6 risk evaluations. Notwithstanding EPA's choice to issue COU-specific risk
determinations to date, EPA interprets its risk evaluation regulation to also allow the Agency to
issue whole chemical risk determinations. Either approach is permissible under the regulation.

In response to commenters' assertions that EPA has not supported the claim that the whole
chemical approach to risk determination is science-based, EPA emphasizes that the revised
unreasonable risk determination for PCE is based on the peer reviewed risk characterization in
the December 2020 PCE Risk Evaluation, based on reasonably available information pursuant to
TSCA section 26(k) and 40 CFR 702.33, and developed in accordance with TSCA section 26(h)
and (i) to make decisions under TSCA section 6 in a manner consistent with the best available
science and based on the weight of scientific evidence.

EPA has articulated the basis for a whole chemical approach to PCE in detail in the Federal
Register Notice announcing the availability of the draft revised risk determination for PCE. As
explained therein, the Agency has inherent authority to replace, revise, reconsider, or repeal
previously made decisions to the extent permitted by law, with a reasoned explanation. FCC v.
Fox Television Stations, Inc., 556 U. S. 502, 515 (2009); see also Motor Vehicle Mjrs. Ass 'n v.
State Farm Mutual Auto. Ins. Co., 463 29, 42 (1983). The revised unreasonable risk
determination for PCE reflects EPA's objective of conducting a technically sound, manageable
evaluation to determine whether the chemical substance—not just individual uses or activities—
presents an unreasonable risk. EPA plans to consider the appropriate approach for each chemical
substance risk evaluation on a case-by-case basis, taking into account considerations relevant to
the specific chemical substance. In the case of PCE, 60 of the 61 conditions of use drive the
unreasonable risk and the chemical-specific properties cut across the conditions of use within the
scope of the risk evaluation; therefore, EPA has concluded that the risk determination for PCE is
better characterized by the whole chemical approach. EPA believes this is a reasonable approach
under TSCA and the Agency's implementing regulations.

10


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

Responding to commenters' ideas concerning conditions of use which were identified in the
December 2020 PCE Risk Evaluation as not presenting unreasonable risk, and what commenters
describe as the benefits of a COU-specific approach, in this final revised risk determination, EPA
identifies which conditions of use drive the unreasonable risk and which conditions of use do not
drive the unreasonable risk of PCE. Consistent with the statutory requirements of TSCA section
6(a), EPA will propose risk management actions to the extent necessary so that PCE no longer
presents an unreasonable risk. EPA expects to focus its risk management action on the conditions
of use that drive the unreasonable risk. Therefore, it is expected that EPA's risk management
actions will focus on the conditions of use that drive the unreasonable risk. EPA does not expect
that the issuance of a whole chemical risk determination for PCE will affect the efficiency of
EPA's risk management rulemaking. However, it should be noted that, under TSCA section 6(a),
EPA is not limited to regulating the specific activities found to drive unreasonable risk and may
select from among a suite of risk management requirements in section 6(a) related to
manufacture (including import), processing, distribution in commerce, commercial use, and
disposal as part of its regulatory options to address the unreasonable risk. As a general example,
EPA may regulate upstream activities (e.g., processing, distribution in commerce) in order to
address downstream activities (e.g., consumer uses) driving unreasonable risk even if the
upstream activities do not drive the unreasonable risk.

Furthermore, there is no change in the underlying PCE risk characterization with regard to
conditions of use that may relate to articles. Under TSCA section 6(c)(2)(E), any relevant
consideration of articles will take place during the risk management rulemaking stage, based on
the risk evaluation findings. The public will have an opportunity to provide comments and any
additional information during the comment period of the proposed risk management rule.

Section 5.1.3 - Inconsistency with TSCA and Risk Evaluation Rule

Several industry trade organizations (0135, 0120, 0123, 0127) provided their view that a whole
chemical approach is inconsistent with TSCA and its implementing regulations.

Basis for the whole chemical approach

An industry trade organization (0120) stated that by proposing a whole chemical approach, EPA
contradicted TSCA and its implementing regulations, did not use sound reasoning, and lacked
science-based justification to be in compliance with TSCA section 26. It and another industry
trade organizations (0120, 0123) cited TSCA section 6(b)(4)(F)(i) and (iv) and stated that EPA
must integrate and assess available information on hazards and exposures for the COUs of the
chemical substance and consider the likely duration, intensity, frequency and number of
exposures under the COUs. Other industry trade organizations (0127, 0136) claimed that TSCA
requires that changes in approach have scientific support, citing TSCA section 26 and stating that
EPA did not provide a scientific basis for the whole chemical approach.

Two industry trade organizations (0122, 0131) stated that EPA's whole chemical approach for
unreasonable risk determination is based on hazard rather than risk and thus contrary to TSCA.
One of the commenters (0131) provided its view that the Risk Evaluation Rule requires that risk
evaluations be comprehensive and thus that risk determinations must be based on all conditions

11


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

of use rather than driven by a subset of uses. The commenter further described at length their
position that EPA used a hazard-based approach because the Agency did not consider aggregate
exposures across conditions of use under TSCA section 6(b)(4)(F)(ii) in its 2020 final risk
evaluation for PCE and did not consider risk holistically, as would be required in a risk
characterization. The commenter also stated that a whole chemical risk determination would be
less useful than COU-specific ones, and thus that such an approach is contrary to TSCA section
6(b).

An industry trade organization (0120) commented that language in the HBCD final risk
determination and PCE draft revised risk determination departs from the draft revisions to the
risk determinations for HBCD and PV29. The commenter stated that EPA's use of "substantial
amount" of conditions of use to support application of a whole chemical approach is more
arbitrary than the "majority" of conditions language used in the earlier draft revisions. The
industry trade organization stated its view that this "substantial amount" term is inconsistent with
TSCA section 26's requirements that section 6 decisions be grounded in science and thus that
EPA's revision lacks a reasoned explanation.

Inconsistency with TSCA

Several commenters wrote that the draft revision is inconsistent with TSCA. An industry trade
organization (0123) stated its view that a whole chemical approach would functionally disable
TSCA section 6(c)(2)(E), as well as Congress' intent for including it, since the provision makes
clear that the extent to which articles should be regulated is dictated by what risks a risk
evaluation identifies as stemming from exposure to a chemical substance in an article, and
articles should not be regulated to ameliorate risk presented by other conditions of use.

An industry trade organization (0123) stated that the whole chemical approach is inconsistent
with the structure created by Congress in the Lautenberg Amendments to TSCA in 2016.
Specifically, one of the industry trade organizations (0123) said that future risk evaluations will
be conducted for chemical substances that EPA has already determined "may present" an
unreasonable risk through the prioritization process. The commenter stated that if the whole
chemical approach is used, the distinction between the "may present" an unreasonable risk
standard for prioritization and the "presents" standard for triggering risk management regulations
would be lost.

The commenter, as well as another industry trade organization (0120) stated that the practical
effect of the whole chemical approach is that there are unlikely to be any determinations of no
unreasonable risk. The commenters stated their view that the whole chemical approach thus
impermissibly renders parts of the statute - the provisions for a finding of no unreasonable risk -
superfluous. The industry trade organizations stated that the inclusion in the statute of provisions
for a finding of no unreasonable risk, including, for example, TSCA section 18(a)(l)(B)(i), is
evidence that Congress must have intended for specific COUs to be evaluated by the Agency and
risk determinations made for each of those uses. On the other hand, an advocacy group (0125)
discounted this position, providing its view that whether industry actors believe that a whole
chemical approach may result in fewer findings of "no unreasonable risk" has no bearing on the
legitimacy of EPA's approach under TSCA.

12


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

Another industry trade organization (0127) commented that COU-specific risk determinations
are necessary under TSCA because a single whole chemical unreasonable risk determination,
provided in the context of conditions of use that EPA has determined do not present an
unreasonable risk, ignores the possibility of "no unreasonable risk" determinations for a
chemical substance under its conditions of use pursuant to TSCA section 6(i)(l). The commenter
stated its view that all chemicals would be subject to a whole chemical unreasonable risk
determination under EPA's proposed approach because most chemicals facing a TSCA
evaluation would have at least one unreasonable risk under a COU. Finally, the commenter and
another industry trade organization (0136) stated that, because this approach would result in all
evaluated chemicals receiving an unreasonable risk determination, it would effectively render
superfluous TSCA's preemption provision regarding cases of no unreasonable risk.

Similarly, two industry trade organizations (0135, 0120) also stated their position that if the
individual COU approach for unreasonable risk determination is no longer employed, then any
opportunity for obtaining the federal preemption of state or local requirements provided for
under TSCA Section 18(a) for COUs that pose no unreasonable risk would either be delayed by
years until EPA promulgated a final risk management rule or potentially eliminated depending
on the scope of the risk management rule. One commenter (0135) noted that the consequence of
allowing states to issue chemical regulations while EPA assesses a chemical and until EPA
issues a final risk management rule could create an unworkable and confusing set of
requirements for any sector.

In contrast, an advocacy group (0132) stated that in the final revised risk determination for
HBCD, EPA overstated the preemptive effect on state chemical regulation of risk management
rules based on whole chemical risk evaluations. The commenter asserted that, under TSCA
section 18(c)(3), states are not preempted from regulating risks, hazards, or conditions of use that
EPA does not restrict pursuant to TSCA section 6(a), regardless of whether they were evaluated
in the final risk evaluation. The commenter provided its view that the scope of preemption is
defined by the requirements of the section 6(a) risk management rules rather than the contents of
the earlier risk evaluations.

Additionally, an industry trade organization (0136) commented that the whole chemical
approach would contravene policies in TSCA section 3 that direct EPA to not impede unduly or
create unnecessary economic barriers to technological innovation.

Inconsistency with the Risk Evaluation Rule

Two commenters wrote that the whole chemical approach is inconsistent with the Risk
Evaluation Rule. An industry trade organization (0127) commented that the whole chemical
approach would require a separate notice and comment rulemaking because the Risk Evaluation
Rule unambiguously requires COU-specific risk determinations. The industry trade organization
provided its view that EPA's proposal is improper under Kisor because, the commenter
reasoned, 40 C.F.R. § 702.47 unambiguously requires COU-specific determinations. The
commenter provided quotations from the regulation and the preamble to the Risk Evaluation
Rule to support its discussion. Furthermore, the commenter stated its view that 40 C.F.R. §§
702.31(a) and 702.41(a)(6) do not support a whole chemical approach because the former is

13


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

merely introductory, and the latter only reminds readers that the level of detail in each evaluation
may vary. The industry trade organization commented that EPA misplaced reliance on language
from the Proposed Risk Evaluation Rule. The commenter stated that the Final Risk Evaluation
Rule expressly departed from the Proposed Risk Evaluation Rule to implement a COU-specific
approach, providing quotations from both documents. Additionally, another industry trade
organization (0131) stated its view that EPA improperly dismissed a statement from the Risk
Evaluation Rule regarding COU-specific determinations without providing sufficient regulatory
language or rationale to support its departure from that statement. Further, the commenter stated
that any ambiguity in the Final Risk Evaluation Rule as to whole chemical risk determinations
should be understood as whether whole chemical determinations can supplement, rather than
replace, COU-specific determinations.

Finally, an industry trade association (0131) commented in part with a hypothetical example that
it is unreasonable and contrary to 40 C.F.R. § 702.49(c) for EPA to issue a whole chemical
unreasonable risk determination when two conditions of use do not present an unreasonable risk.
The commenter added that it might be appropriate to issue a whole chemical unreasonable risk
determination in addition to individual COU-determinations, but this would only be appropriate
if EPA concluded that the aggregate exposures across all conditions of use would present
unreasonable risks.

EPA RESPONSE:

EPA followed the requirements under TSCA section 6(b)(4) in issuing this revised unreasonable
risk determination for PCE, including all requirements for a risk evaluation under TSCA section
6(b)(4)(F). Specifically, Section 4 of the final risk evaluation describes how EPA integrated and
assessed reasonably available information on hazards and exposures for the conditions of use for
PCE (considering factors such as environmental releases, environmental monitoring and
biomonitoring, as well as toxicity testing and physical and chemical properties), as well to
workers, occupational non-users, consumers, and bystanders, using reasonably available data,
including modeling.

Regarding the comment that risk evaluations should be comprehensive and thus be based on all
conditions of use, in accordance with TSCA section 6(b)(4)(A), EPA evaluates chemical
substances to determine whether they present unreasonable risk under the conditions of use. The
risk evaluation for PCE encompasses the conditions of use within the scope of the risk
evaluation. As set forth in the revised risk determination, EPA has determined that PCE, as a
whole chemical substance, presents an unreasonable risk of injury to health when evaluated
under its conditions of use.

As EPA explained in the Federal Register Notice announcing the availability of the draft revised
risk determination for PCE, EPA plans to consider the appropriate approach for each chemical
substance risk evaluation on a case-by-case basis, taking into account considerations relevant to
the specific chemical substance in light of the Agency's obligations under TSCA.

Regarding the comment that TSCA requires that changes in approach have scientific support,
EPA notes that the revised unreasonable risk determination for PCE is based on the peer

14


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

reviewed risk characterization in the December 2020 PCE Risk Evaluation, based on reasonably
available information pursuant to TSCA section 26(k) and 40 CFR 702.33, and developed in
accordance with TSCA section 26(h) and (i) to make decisions under TSCA section 6 in a
manner consistent with the best available science and based on the weight of scientific evidence.

EPA emphasizes that the Agency is not amending the underlying scientific analysis. EPA also
views the peer reviewed hazard and exposure assessments and associated risk characterization as
robust and upholding the standards of best available science and weight of the scientific evidence
per TSCA sections 26(h) and (i). (87 FR 39085 (June 30, 2022)). The policy changes do not
impact the characterization of risk estimates by condition of use (and summarized in Section 4.2
of the final risk evaluation), or the occupational exposures to workers and ONUs (and
summarized in Section 2.4 of the final risk evaluation), including an explanation of the different
exposures between workers and ONUs, given the different tasks workers perform under each
condition of use. EPA also notes that the assertion that the Agency based its determination on
hazard alone is not correct; the revised unreasonable risk determination is based on both the
hazard of the chemical substance and the exposures or environmental releases, as described in
Sections 3 and 2, respectively, of the December 2020 PCE Risk Evaluation, and further
explained in Sections 5.2 and 5.3 of the revised unreasonable risk determination. EPA disagrees
that a whole chemical approach is appropriate only for an aggregate assessment.

The revised unreasonable risk determination for PCE reflects EPA's objective of conducting a
technically sound, manageable evaluation to determine whether the chemical substance—not just
individual uses or activities—presents an unreasonable risk. In this instance a "substantial
amount" of conditions of use that drive the unreasonable risk encompasses 60 out of the 61
conditions of use of PCE. A "substantial amount" of conditions of use driving the unreasonable
risk is just one of the chemical specific reasons why EPA is making a whole chemical
unreasonable risk determination for PCE. Moreover, for PCE, those conditions of use span the
lifecycle of the chemical substance—from manufacturing (including import), processing,
industrial and commercial use, consumer use, and disposal for worker, ONU, consumer, and
bystander health, and the severity of the health effects associated with PCE exposures. Since
these chemical-specific properties cut across the conditions of use within the scope of the risk
evaluation, the Agency's risk findings and conclusions encompass a substantial amount of the
conditions of use and the Agency is better positioned to achieve its TSCA objectives for PCE
when using a whole chemical unreasonable risk determination for PCE, EPA concludes that the
Agency's risk determination for PCE is better characterized as a whole chemical risk
determination rather than COU-specific risk determination. In the case of PCE, 60 out of 61
conditions of use drive the unreasonable risk and the chemical-specific properties cut across the
conditions of use within the scope of the risk evaluation; therefore, EPA has concluded that the
risk determination for PCE is better characterized by the whole chemical approach. EPA believes
this is a reasonable approach under TSCA and the Agency's implementing regulations, including
requirements under TSCA section 26(h) and (i) that section 6 decisions are consistent with the
best available science and are supported by the weight of scientific evidence.

15


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

As explained in the Federal Register Notice to the draft revised unreasonable risk determination
for PCE, EPA has the inherent authority to reconsider previous decisions when permitted by law
and supported by reasoned explanation. FCC v. Fox Television Stations, Inc., 556 U.S. 502, 515
(2009); see also Motor Vehicle Mjrs. Ass'nv. State Farm Mutual Auto. Ins. Co., 463 U.S. 29, 42
(1983). EPA acknowledges a lack of specificity in the statute and inconsistency in the
regulations with respect to the presentation of risk determinations in TSCA section 6 risk
evaluations. In the December 2020 PCE Risk Evaluation, EPA applied 40 CFR 702.47 based on
one particular passage in the preamble to the final Risk Evaluation Rule2, which stated: "The
final step of a risk evaluation is for EPA to determine whether the chemical substance, under the
conditions of use, presents an unreasonable risk of injury to health or the environment. EPA will
make individual risk determinations for all uses identified in the scope. This part of the
regulation is slightly amended from the proposed rule, to clarify that the risk determination is
part of the risk evaluation, as well as to account for the revised approach to [sic] that ensures
each COU covered by the risk evaluation receives a risk determination." 82 FR 33726, 33744.
However, in contrast to this portion of the preamble of the final Risk Evaluation Rule, the
regulatory text itself and other statements in the preamble reference a risk determination for the
chemical substance under its conditions of use, rather than separate risk determinations for each
of the conditions of use of a chemical substance. The text of 40 CFR 702.47 states: "[a]s part of
the risk evaluation, 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, either in a single decision document or in multiple decision
documents" (emphasis added). Other language reiterates this perspective. For example, 40 CFR
702.31(a) states that the purpose of the rule is to establish the EPA process for conducting a risk
evaluation to determine whether a chemical substance presents an unreasonable risk of injury to
health or the environment as required under TSCA section 6(b)(4)(B). Likewise, there are
recurring references to whether the chemical substance presents an unreasonable risk in 40 CFR
702.41(a). Notwithstanding the one preambular statement about COU-specific risk
determinations, the preamble to the final rule also contains support for a risk determination on
the chemical substance as a whole. In discussing the identification of the conditions of use of a
chemical substance, the preamble notes that this task inevitably involves the exercise of
discretion on EPA's part, and, "[a]s EPA interprets the statute, the Agency is to exercise that
discretion consistent with the objective of conducting a technically sound, manageable
evaluation to determine whether a chemical substance—not just individual uses or activities—
presents an unreasonable risk." (82 FR at 33729).

Therefore, notwithstanding EPA's choice to issue COU-specific risk determinations to date, EPA
interprets its risk evaluation regulation to also allow the Agency to issue whole chemical risk
determinations. Either approach is permissible under the regulation, and the Agency's
interpretation is entitled to Auer deference when using the multifactor test set forth in Kisor. As

2 Procedures for Chemical Risk Evaluation Under the Amended Toxic Substances Control Act (82 FR 33726) (July
20, 2017).

16


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

such, notice and comment rulemaking is not necessary before revising the PCE risk
determination.

The unreasonable risk determination does not consider costs or other nonrisk factors. In making
the unreasonable risk determination, EPA considers relevant risk-related factors, 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 PESS); the severity of hazard (including the nature of the
hazard, the irreversibility of the hazard); and uncertainties. EPA takes into consideration the
Agency's confidence in the data used in the risk estimate. This includes an evaluation of the
strengths, limitations, and uncertainties associated with the information used to inform the risk
estimate and the risk characterization. Therefore, the PCE chemical unreasonable risk
determination takes in consideration the hazard of PCE and the exposures from all conditions of
use of PCE.

Furthermore, there is no change in the underlying PCE risk evaluation. EPA disagrees that a
COU-specific risk determination is more useful than a whole-chemical risk determination
because EPA has transparently described which conditions of use do or do not drive EPA's
determination. In the final revised risk determination, EPA identifies which conditions of use
drive the unreasonable risk of PCE. Consistent with the statutory requirements of TSCA section
6(a), EPA will propose risk management action to the extent necessary so that PCE no longer
presents an unreasonable risk. EPA expects to focus its risk management action on the conditions
of use that drive the unreasonable risk. However, it should be noted that, under TSCA section
6(a), EPA is not limited to regulating the specific activities found to drive unreasonable risk and
may select from among a suite of risk management requirements in section 6(a) related to
manufacture (including import), processing, distribution in commerce, commercial use, and
disposal as part of its regulatory options to address the unreasonable risk. As a general example,
EPA may regulate upstream activities (e.g., processing, distribution in commerce) in order to
address downstream activities (e.g., consumer uses) driving unreasonable risk even if the
upstream activities do not drive the unreasonable risk.

TSCA section 18(c)(3) defines the scope of federal preemption with respect to any final rule
EPA issues under TSCA section 6(a). That provision provides that federal preemption of
"statutes, criminal penalties, and administrative actions" applies 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 [TSCA section 6(a)]." EPA reads this to mean that states are
preempted from imposing requirements through statutes, criminal penalties, and administrative
actions relating to any "hazards, exposures, risks, and uses or conditions of use" evaluated in the
final risk evaluation and informing the risk determination that EPA addresses in the TSCA
section 6(a) rulemaking. For example, federal preemption applies even if EPA does not regulate
in that final rule a particular COU, as long as that COU was evaluated in the final risk evaluation.

Regarding the comment referencing TSCA section 6(c)(2)(E) and the concern regarding
regulation of articles, EPA notes that the Agency has not identified conditions of use of PCE that
include articles. If a condition of use included an article and it was determined to drive the

17


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

unreasonable risk, EPA would apply any prohibitions or restrictions consistent with TSCA
section 6(c)(2)(E) when regulating the unreasonable risk driven by an article. Specifically, EPA
emphasizes that there is no change in the underlying PCE risk evaluation nor in the proposed
revised risk determination for PCE with regard to conditions of use that may relate to
replacement parts or articles. The revised risk determination identifies conditions of use that
drive unreasonable risk from PCE. Under TSCA section 6(c)(2) (D) and (E), any relevant
consideration of replacement parts and articles will take place during the risk management
rulemaking stage, based on the risk evaluation findings. The public will have an opportunity to
provide comments and any additional information during the comment period of the proposed
risk management rule.

Similarly, in response to the comment regarding barriers to technological innovation, EPA notes
that TSCA section 2(b)(3) specifies that "authority over chemical substances and mixtures
should be exercised in such a manner as not to impede unduly or create unnecessary economic
barriers to technological innovation while fulfilling the primary purpose of [TSCA] to assure that
such innovation and commerce in such chemical substances and mixtures do not present an
unreasonable risk of injury to health or the environment." Consistent with the statutory
requirements of TSCA section 6(a), EPA will propose risk management action to the extent
necessary so that PCE no longer presents an unreasonable risk. As required by TSCA section
6(c)(2)(A), when proposing and promulgating a TSCA section 6(a) rule for PCE, EPA will
consider and publish a statement based on reasonably available information with respect to
factors including the reasonably ascertainable economic consequences of the rule. The
considerations related to reasonably ascertainable economic consequences include, but are not
limited to, considerations of the likely effect of the rule on the national economy, small business,
technological innovation, the environment, and public health.

EPA also notes that there are separate statutory standards and processes for designating chemical
substances as high-priority for risk evaluation and conducting TSCA risk evaluations. Under
TSCA section 6(b), EPA must designate as a high-priority substance "a chemical substance that
the Administrator concludes, without consideration of costs or other nonrisk factors, may present
an unreasonable risk of injury to health or the environment because of a potential hazard and a
potential route of exposure under the conditions of use, including an unreasonable risk to a
potentially exposed or susceptible subpopulation identified as relevant by the Administrator."
(TSCA section 6(b)(l)(B)(i)). EPA is required to consider statutorily-prescribed factors when
conducting prioritization and to provide several opportunities for public comment, and the
prioritization process must last between 9-12 months (TSCA section 6(b)(1)(A), (C)). Once EPA
designates a chemical substance as a high-priority substance for risk evaluation, EPA must then
initiate a longer 3- to 3.5-year risk evaluation process. Through that risk evaluation process, EPA
must "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 identified as relevant to
the risk evaluation by the Administrator, under the conditions of use." (TSCA section
6(b)(4)(A)). That process is subject to separate statutory requirements and considerations
applicable to risk evaluations (e.g., TSCA section 6(b)(4)(D), (F)). If EPA finds unreasonable
risk through a risk evaluation, EPA must proceed to address that unreasonable risk through
TSCA section 6(a) risk management action. Although EPA must conduct a risk evaluation after

18


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

designating a chemical substance as a high-priority substance, and the reasonably available
information and findings informing prioritization will also inform EPA's risk evaluation on a
high-priority substance, the standards and processes for TSCA prioritization and risk evaluation
are separate and distinct.

Section 5.1.4 - Other comments on the whole chemical approach

Two trade organizations (0120, 0123) requested that EPA:

•	Review the whole chemical approach in the context of TSCA's risk-based decision-
making framework and requirements for risk management rules (0120);

•	Explain how the change to a whole chemical approach may affect risk management
(0120, 0123);

•	Develop principles and criteria that would dictate when and how the whole chemical
approach would be applied and when it would not (e.g., will it be applied if 50% of the
COUs show unreasonable risk? 10%? at least one?) (0120, 0123). How will EPA treat the
COUs that it determines do not present an unreasonable risk in its risk management plan
when a whole chemical approach has been taken? (0120); and

•	Explain how the whole chemical approach is employed in a manner consistent with the
best available science or a weight of scientific evidence approach or compelled by the
factors and standards dictated by Congress in the amendments to TSCA section 26
(0123).

EPA RESPONSE:

EPA appreciates other comments received in connection with the PCE draft revised unreasonable
risk determination. As stated previously, this action pertains only to the risk determination for
PCE. While EPA may consider similar actions on other first ten chemicals, EPA is taking a
chemical-specific approach to reviewing these risk evaluations and is incorporating new policy
direction in a surgical manner, while being mindful of Congressional direction on the need to
complete risk evaluations and move toward any associated risk management activities.

The revised unreasonable risk determination for PCE is based on the peer reviewed risk
characterization of the December 2020 risk evaluation, which is based on reasonably available
information pursuant to TSCA section 26(k) and 40 CFR 702.33, and developed in accordance
with TSCA section 26(h) and (i) to make decisions under TSCA section 6 in a manner consistent
with the best available science and based on the weight of scientific evidence. Changing the risk
determination to a whole chemical approach does not impact the underlying data and analysis
presented in the risk characterization of the risk evaluation.

For PCE, the whole chemical approach is appropriate because there are benchmark exceedances
for substantial number of conditions of use (spanning across most aspects of the chemical
lifecycle-from manufacturing (including import), processing, industrial and commercial use, and
disposal) for worker and ONU health, and the severity of the health effects associated with PCE
exposures. Since these chemical-specific properties cut across the conditions of use within the

19


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

scope of the risk evaluation, the Agency's risk findings and conclusions encompass a substantial
amount of the conditions of use and the Agency is better positioned to achieve its TSCA
objectives for PCE when using a whole chemical unreasonable risk determination for PCE, EPA
concludes that the Agency's risk determination for PCE is better characterized as a whole
chemical risk determination rather than COU-specific risk determination.

With respect to the risk management, consistent with the statutory requirements of TSCA section
6(a), EPA will propose risk management action to the extent necessary so that PCE no longer
presents unreasonable risk. In the final revised risk determination for PCE, EPA has identified
the conditions of use that drive the unreasonable risk for PCE and will focus its risk management
efforts on addressing that unreasonable risk, as required by TSCA. Regarding how EPA may
treat the COUs that it determines do not drive the unreasonable risk, EPA notes that, under
TSCA section 6(a), EPA is not limited to regulating the specific activities found to drive
unreasonable risk and may select from among a suite of risk management options related to
manufacture, processing, distribution in commerce, commercial use, and disposal in order to
address the unreasonable risk. For instance, EPA may regulate upstream activities (e.g.,
processing, distribution in commerce) in order to address downstream activities driving
unreasonable risk (e.g., consumer use) even if the upstream activities do not drive the
unreasonable risk. The public will have another opportunity to provide comments during the
comment period of the proposed risk management rule.

Section 5.2 - Baseline scenario that does not assume PPE or other mitigation measures in
place

Section 5.2.1 - Support for EPA's intention not to assume PPE or other mitigation
measures are in place

Several non-governmental environmental and health advocacy groups (0125, 0132, 0121)
supported EPA's decision to no longer rely on the assumption that workers always and properly
use PPE when determining unreasonable risk, agreeing that EPA's baseline for determining risk
to workers should not assume the use of PPE. One advocacy organization (0141) stated that the
initial assumption regarding PPE lacked legal basis, departed from established federal workplace
protection policy and practice, and is contrary to the realities of worker exposure to chemicals.
The advocacy organization stated that EPA's revised policy approach follows the
recommendation of its Science Advisory Committee on Chemicals (SACC) to base unreasonable
risk determinations for workers on measured or estimated exposure levels in the absence of PPE.

Two advocacy organizations (0125, 0132) discussed the many limitations of PPE, including
EPA's own statements that respirators are often not feasible and may be used only intermittently
by workers even where legally required. The commenters stated their view that the U.S.
Occupational Safety and Health Administration (OSHA) and the National Institute for
Occupational Safety and Health (NIOSH), too, have acknowledged the limitations of PPE,
having prioritized hazard elimination, substitution, engineering and administrative controls over
the use of PPE in the hierarchy of controls. An advocacy organization (0125) said that PPE does
not address exposures to workers who are bystanders, as they are not wearing the PPE, and

20


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

further stated its view that the use of a respirator cannot be used to determine if exposure is
lessened sufficiently so that unreasonable risk is mitigated, because EPA does not know the
baseline for a particular facility. The same commenter warned that OSHA regulations concerning
PPE only apply when the employer determines that workers are subject to sufficient hazards
from chemical exposure and whenever else the employer decides it is necessary. Therefore, the
employer decides both whether and what hazards exist and whether use of PPE is necessary. One
of the advocacy organizations (0132) also noted the SACC's assessment that EPA's
characterization of unreasonable risk relying on use of PPE is not sufficiently supported by the
practical realities of many workplaces.

Another commenter (0121) said that the NAS reported that the vast majority of workplaces do
not have a respiratory protection program and estimated that roughly 3.3 percent of American
workers are protected by the respiratory protection program issued under OSHA standards. The
commenter concluded that the revised risk determination accurately reflects the risks workers
face.

An advocacy organization (0125) cited TSCA section 6(b)(4)(A), stating that this provision
precludes EPA from considering risk mitigation in its workplace risk determinations. The
advocacy organization claimed that consideration of the use of PPE - or any other mechanism to
mitigate exposure and risk - is a non-risk factor and should thus not be considered in any form as
part of the risk evaluation.

EPA RESPONSE:

EPA appreciates the feedback concerning assumptions on the use of PPE in the PCE risk
evaluation and the unreasonable risk determination therein, general input regarding PPE, the
interaction of EPA and OSHA regulation, and worker protection.

As stated in the revised unreasonable risk determination for PCE, EPA believes it is appropriate
to evaluate the levels of risk present in scenarios considering applicable OSHA requirements, as
well as scenarios considering industry or sector best practices for industrial hygiene because such
evaluation can help inform potential risk management actions (i.e., by informing EPA's
assessment of the feasibility and efficacy of different risk management options). However, as
commenters note, EPA cannot reasonably assume that all facilities will have adopted these
practices. Additionally, as commenters note, workers not directly engaged in handling the
chemical (such as occupational non-users (ONUs)) are not expected to be provided or wear PPE.
Therefore, EPA is making its determination of unreasonable risk from a baseline scenario that
does not assume compliance with OSHA standards, including any applicable exposure limits or
requirements for use of respiratory protection or other PPE. This reflects EPA's recognition that
unreasonable risk may exist for subpopulations of workers that may be highly exposed because
they are not covered by OSHA standards, or because their employer is out of compliance with
OSHA standards, or because many of OSHA's chemical-specific permissible exposure limits
largely adopted in the 1970's are described by OSHA as being "outdated and inadequate for

21


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

ensuring protection of worker health,"3 or because the OSHA PEL alone may be inadequate to
protect worker health, or because EPA finds unreasonable risk for purposes of TSCA
notwithstanding existing OSHA requirements. The use of PPE as a potential means of addressing
unreasonable risk will be considered during risk management, as appropriate.

Consistent with TSCA section 9(d), EPA is consulting and coordinating TSCA activities with
OSHA, NIOSH, and other relevant federal agencies for the purpose of achieving the maximum
applicability of TSCA while avoiding the imposition of duplicative requirements. Consultation
with other relevant federal agencies is also required during the risk evaluation process under
EPA's implementing regulations at 40 CFR 702.39. EPA will continue to coordinate with
OSHA, NIOSH, and other relevant federal agencies during TSCA risk evaluation and risk
management activities and expects to refine its consultation process as the Agency conducts
additional risk evaluations and risk management rulemakings.

In accordance with TSCA section 26(k), EPA considers reasonably available information when
conducting TSCA section 6 risk evaluations and risk management rules. When undertaking risk
determinations as part of TSCA risk evaluations, EPA cannot assume as a general matter that
workers always or properly use PPE, although it does not question the public comments received
regarding the occupational safety practices often followed by industry respondents. Under TSCA
section 6(a), EPA must apply one or more risk management requirements to the extent necessary
so that a chemical substance no longer presents unreasonable risk. Those requirements may
include restrictions on the manufacture, processing, distribution in commerce, commercial use,
or disposal of a chemical substance.

Section 5.2.2 - Opposition to EPA's intention not to assume PPE or other mitigation
measures are in place

Several commenters expressed opposition to EPA's proposal to not assume the use of PPE when
making its unreasonable risk determination for PCE. For example, some industry trade
organizations (0123, 0120, 0131, 0136, 0127) commented that EPA's decision not to assume the
use of PPE is inconsistent with the requirement to consider COUs under TSCA and contravenes
explicit requirements under TSCA section 26(k) to take into consideration information relating to
a chemical substance or mixture, including hazard and exposure information, under the COUs,
that is reasonably available to the Administrator. One industry trade organization (0123) added
that when EPA rendered unreasonable risk determinations in the PCE risk evaluation and the
other nine initial risk evaluations, EPA's assumption that workplaces comply with the OSHA
regulations was reasonable, appropriate, and driven by data. The industry trade organization
stated its view that such an approach is grounded in the statute and regulations and is supported
by sound science. Similarly, an industry trade organization (0136) stated that EPA has not
sufficiently supported its refusal to acknowledge the standard use of PPE practices utilized by
industry and regulated by OSHA.

3 As noted on Occupational Safety and Health Administration. Permissible Exposure Limits - Annotated Tables.
Accessed June 13, 2022. https://www.osha.gov/an.notated-peis.

22


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

An industry trade organization (0120) emphasized that EPA's proposal to determine risk without
considering the effects of current occupational safety standards and PPE practices is not
supported by the record nor reasonably justified by any of the reasons offered by the Agency.
Specifically, the commenter provided its view that EPA cited no data or records to support its
belief concerning the insufficiency of PPE at OSHA regulated facilities. The commenter further
stated that EPA also has not presented any evidence of widespread refusal to comply with OSHA
requirements and stated its view that OSHA does require the use of appropriate PPE where
needed to protect workers from chemical exposures at jobsites. Similarly, another industry trade
organization (0135) stated that EPA's proposed approach would likely leave the public with the
perception that facilities are out of compliance with federal and state safety standards, would
artificially increase the calculated human health risk for particular uses of a chemical, and would
create a false and misleading perception of worker risk.

An industry trade organization (0135) stated that if EPA believes that certain workplace risks are
not being adequately controlled, then EPA has an obligation under TSCA section 9(a) to consult
with OSHA before superseding OSHA's authority. Any such result from coordination and
consultation with OSHA should also be made publicly available to further transparency, process,
and due diligence. A couple of industry trade organizations (0131, 0130, 0127) stated that,
during the first risk determination for PCE, EPA relied on information such as OSHA
requirements, information supplied in public comments, and safety data sheets, but did not
explain why this information was not valid in the revised risk determination. One industry trade
organization (0131) also said that in the December 2020 risk evaluation, EPA evaluated
conditions of use both with and without protective measures, which best informs the
unreasonable risk determination and the magnitude of potential risks. The commenter said that,
in order for EPA to now determine unreasonable risk and regulate chemical substances to the
extent that the substance no longer presents an unreasonable risk, it must assume "intentional
misuse" as though OSHA has no meaningful legal effect. According to the commenter, the
assumption of misuse contradicts EPA's affirmation in the draft revised risk determination that it
does not question the public comments received on the original draft risk determination,
including those discussing practices of providing PPE to employees and following established
worker protection standards. The commenter said that if EPA does not use reasonably available
information to ground its evaluation of the substance under specific conditions of use, it is
characterizing hazard, instead of risk.

An industry trade organization (0128) stated that there are three PCE manufacturers in the U.S.,
and they have all submitted documentation to EPA describing the level of required PPE for
general nonspecific tasks in a manufacturing plant, as well as the extensive training in place for
employees. The commenter stated that since PPE is known to be used in a manufacturing plant
and that information has been clearly articulated to EPA, EPA must evaluate the COU based on
the levels of risk present in the scenarios considering applicable OSHA requirements and
industry best practices.

An industry trade organization (0130) stated that OSHA general requirements include PPE, and
EPA cannot base its determination that PPE cannot be assumed in the base case on a single line

23


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

from an OSHA publication. The commenter said that this is insufficient considering EPA's own
findings concerning the use of PPE and its evaluation of both PPE and non-PPE risk scenarios.

An industry trade organization (0127) stated that without supporting record evidence or analysis
for its assumption, EPA's decision to no longer assume the use of PPE is not reasonable and
should be withdrawn. Similarly, an industry trade organization (0129) stated that manufacturers
are required to follow OSHA standards and have communicated data to EPA about PPE use. The
commenter stated that the non-consideration of PPE and engineering controls effectively leaves
the risk determination as a hazard-based standard, which is inconsistent with the risk-based intent
of TSCA.

An industry trade organization (0120) stated that EPA's proposal is not transparent about its
plans for implementation of the proposed change in the risk management rule itself and would
request the Agency to develop clear, accurate communication materials to explain EPA's new
approach to PPE to the already OSHA-regulated community. The commenter stated that EPA's
proposal could inadvertently create regulatory confusion and potentially subject companies to
overlapping workplace protection requirements for workplaces that are already subject to OSHA.
The industry trade organization added that such requirements would be costly and either
duplicative of or inconsistent with those that OSHA has already imposed on employers and
employees in OSHA-regulated businesses. Further, the commenter stated its view that EPA's
rationale for no assumption of PPE in risk evaluations is inconsistent with the statutory and
regulatory requirements in the Occupational Safety and Health Act of 1970 (OSH Act) and that
EPA must consult with OSHA and NIOSH to understand whether current worker protection
from exposure to chemicals is consistent with best available science before making any
determinations about the adequacy of OSHA controls.

An industry trade organization (0135) suggested that EPA continue the approach of presenting
both scenarios - PCE use with and without PPE - in its risk determinations, claiming that doing
so would provide the appropriate bounding scenarios for PCE risk exposures in the workplace.
The same commenter stated that waiting until EPA proceeds to the risk management phase to
include the use of OSHA-required PPE and related workplace standards creates a false
impression of risk that lacks transparency, will be misleading to the public, and overestimates the
risk of exposure in workplaces that require workers to follow PPE practices. In addition, it would
create an extra layer of work for EPA and industries to work through the risk management phase,
when adequate protections may already be in place.

A product manufacturer (0133) stated that, while they understand EPA's decision to assume no
PPE or other mitigation measures are in place is only one part of the overall risk evaluation, the
revision would have dramatically negative consequences on the aerospace industry's
manufacture of commercial and defense products and ignores the successful efforts of companies
that mandate and enforce the use of PPE. The commenter said that this is a sweeping and
arbitrary assumption that is not applicable to the aerospace industry. Similarly, an industry trade
organization (0122) stated that, to assume that workers in petroleum refineries are not wearing
PPE is to assume that they are not complying with the law, which is arbitrary and unreasonable.
The commenter said that illegal actions are not normal conditions of use and have never been

24


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

part of risk evaluations under TSCA section 6. Another industry trade organization (0130) stated
that EPA's decision to assume no PPE use is arbitrary and capricious. Another industry trade
coalition (0137) stated that this assumption is incorrect and does not apply to the use of
chlorinated materials as feedstock in chemical synthesis, as all facilities are covered by OSHA
and must use PPE.

EPA RESPONSE:

In the final risk evaluations for the first ten chemical substances, the previous administration
generally assumed that for certain conditions of use workers were always provided, and used,
PPE in a manner that achieved the stated assigned protection factor (APF) for respiratory
protection, or protection factor (PF) for dermal protection. EPA, however, has revisited the
assumption that PPE is always used, and always used properly and effectively, in occupational
settings when making risk determinations for chemical substances and this revised approach is
reflected in the revised unreasonable risk determination for PCE. Regarding the commenter's
assertion that OSHA general requirements include PPE, and that EPA has an insufficient
rationale for basing the determination without assuming use of PPE, EPA notes that the Agency
made this change in approach due to data on violations of PPE use that indicated assumptions
that PPE is always provided to workers, and worn properly, are not justified.4 EPA understands
that there could be occupational safety protections in place at workplace locations; however, not
assuming use of PPE reflects EPA's recognition that unreasonable risk may exist for
subpopulations of workers that may be highly exposed because they are not covered by OSHA
standards, or their employers are out of compliance with OSHA standards, or because many of
OSHA's chemical-specific permissible exposure limits largely adopted in the 1970's are
described by OSHA as being "outdated and inadequate for ensuring protection of worker
health,"5 or because the OSHA PEL alone may be inadequate to protect worker health, or
because EPA finds unreasonable risk for purposes of TSCA notwithstanding OSHA
requirements. For this reason, EPA does not identify the absence of PPE to be "intentional
misuse" as the commenter asserts. Continued use of this assumption could result in a risk
evaluation that underestimates the risk, and in turn, a risk management rule that may not provide
the needed protections. EPA notes that under TSCA section 6(b)(4)(A), EPA is instructed to
conduct risk evaluations "to determine whether a chemical substance presents an unreasonable
risk of injury to health or the environment..., 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." TSCA section 3(12) defines "potentially exposed or
susceptible subpopulation" as "a group of individuals within the general population identified by
the Administrator 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." That definition
provides examples of subpopulations that may be identified as PESS but provides EPA
discretion to identify relevant PESS that will be evaluated in each risk evaluation. For purposes

4	OSHA Standards and Violation Data https://www.osha.gov/toplOcitedstandards

5	As noted on Occupational Safety and Health Administration. Permissible Exposure Limits - Annotated Tables.
Accessed June 13, 2022. https://www.osha.gov/an.notated-pels.

25


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

of the PCE risk evaluation, EPA has identified workers and ONUs as PESS because these
subpopulations experience greater exposure than the general population. This includes workers
and ONUs that may not be covered by OSHA PPE requirements and other OSHA standards.
EPA is not restricted in its identification or evaluation of workers or ONUs at commercial and
industrial facilities that engage in relevant COUs.

EPA's final risk determination is explicit insofar as it does not rely on assumptions regarding the
use of PPE in making the unreasonable risk determination under TSCA section 6, even though
some facilities might be using PPE as one means to reduce worker exposures. Information on the
use of PPE as a means of mitigating risk (including public comments received from industry
respondents about occupational safety practices in use) will be considered during the risk
management phase, as appropriate. When conducting the PCE risk evaluation, EPA considered
reasonably available information on PCE hazards and exposures under the conditions of use,
including information on current industry practices, occupational controls and PPE use at
commercial and industrial facilities handling PCE as explained in Section 2.4.1 of the final risk
evaluation. EPA used this information when developing exposure assessments for PCE. This
information is also helpful to inform potential risk management actions. However, as noted
before, EPA cannot reasonably assume that all facilities will have adopted these practices.
Therefore, EPA is making its determination of unreasonable risk from a baseline scenario that
does not assume compliance with OSHA standards, including any applicable exposure limits or
requirements for use of respiratory protection or other PPE.

The revised unreasonable risk determination for PCE is based on the peer reviewed risk
characterization of the December 2020 PCE Risk Evaluation, which is based on reasonably
available information pursuant to TSCA section 26(k) and 40 CFR 702.33, and developed in
accordance with TSCA section 26(h) and (i) to make decisions under TSCA section 6 in a
manner consistent with the best available science. The policy changes in the revised
unreasonable risk determination do not impact the underlying data and analysis presented in the
risk characterization of the risk evaluation, including how the risk estimates of non-cancer effects
to workers from chronic inhalation exposures at the high-end were calculated and summarized in
Table 4-125 of the final risk evaluation.

As described in an earlier response, EPA also notes that the assertion that the Agency based its
determination on hazard alone is not correct; the revised unreasonable risk determination is
based on both the hazard of the chemical substance and the exposures or environmental releases,
as described in Sections 3 and 2, respectively, of the December 2020 PCE Risk Evaluation, and
further explained in Sections 5.2 and 5.3 of the revised unreasonable risk determination. The
final risk evaluation already includes exposure analysis with and without PPE. Table 4-125 in the
final risk evaluation presents risk estimates for each COU with and without PPE. EPA has made
no changes to this analysis. Therefore, removing the assumption that workers always and
appropriately wear PPE when making the unreasonable risk determination does not create a need
for new analysis. The revision to the risk determination clarifies that EPA does not rely on the
assumed use of PPE when making the risk determination for the whole substance. Overall, 60

26


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

conditions of use would drive the PCE whole chemical unreasonable risk determination due to
risks identified for human health.

As described earlier, the revised unreasonable risk determination for PCE is based on the peer
reviewed risk characterization in the December 2020 PCE Risk Evaluation, based on reasonably
available information pursuant to TSCA section 26(k) and 40 CFR 702.33, and developed in
accordance with TSCA section 26(h) and (i) to make decisions under TSCA section 6 in a
manner consistent with the best available science and based on the weight of scientific evidence.

EPA disagrees with those commenters who thought that eliminating the assumed use of PPE for
risk determination purposes would be misleading to the public. EPA explicitly stated in the draft
revised PCE risk determination and accompanying Federal Register Notice that basing the
unreasonable risk determination on the baseline scenario without PPE should not be viewed as an
indication that EPA believes there are no occupational safety protections in place at any location
or that there is widespread non-compliance with applicable OSHA standards. Rather, as
described earlier, it reflects EPA's recognition that unreasonable risk may exist for workers
(which are included in the risk evaluation as a PESS) that may be highly exposed because they
are not covered by OSHA standards, such as self-employed individuals and public sector
workers who are not covered by a State Plan, or because their employer is out of compliance
with OSHA standards, or because many of OSHA's chemical-specific permissible exposure
limits largely adopted in the 1970's are described by OSHA as being "outdated and inadequate
for ensuring protection of worker health,"6 or because the OSHA PEL alone may be inadequate
to protect worker health, or EPA finds unreasonable risk for purposes of TSCA notwithstanding
OSHA requirements. In some cases, baseline conditions may reflect certain mitigation measures,
such as engineering controls, in instances where exposure estimates are based on monitoring data
at facilities that have engineering controls in place.

Because the requirements and application of TSCA and OSHA regulatory analyses differ, it is
appropriate that EPA conduct risk evaluations and, where it finds unreasonable risk to workers,
develop risk management requirements for chemical substances that OSHA also regulates, and it
is understood that EPA's findings and requirements may sometimes diverge from OSHA's.
However, it is also appropriate that EPA consider the standards that OSHA has already
developed, so as to limit the compliance burden to employers by aligning management
approaches required by the agencies, where alignment will adequately address unreasonable risk
to workers.

In response to the industry commenters who provided their view regarding assumptions in the
aerospace industry, petroleum refineries, and chemical manufacturing and synthesis, EPA
appreciates the information provided and emphasizes that, when undertaking risk management
actions, EPA will consider occupational risk mitigation measures that could address

6 As noted on Occupational Safety and Health Administration. Permissible Exposure Limits - Annotated Tables.
Accessed June 13, 2022. https://www.osha.gov/an.notated-peis.

27


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

unreasonable risk identified by EPA, and for any such measures included in a proposed or final
TSCA risk management rule, EPA intends to strive for consistency with applicable OSHA
requirements and industry best practices, including appropriate application of the hierarchy of
controls, to the extent that applying those measures would address the identified unreasonable
risk, including unreasonable risk to potentially exposed or susceptible subpopulations. As a
general matter, when undertaking risk management actions, EPA intends to develop occupational
risk mitigation measures to address any unreasonable risks identified by EPA, especially in cases
where current OSHA standards may not apply or be sufficient to address the unreasonable risk.
EPA also notes that the unreasonable risk determination does not consider costs or other nonrisk
factors; EPA intends to consider information regarding potential consequences on manufacture
of products during risk management, consistent with TSCA section 6.

EPA identified the conditions of use that drive the unreasonable risk in the risk determination,
and options will be developed during the process of the Agency working on the risk management
rulemaking to address the unreasonable risk presented by the chemical substance. The risk
management rulemaking stage is not when EPA determines which conditions of use drive the
unreasonable risk.

Under TSCA section 9(a), if EPA determines, in the Administrator's discretion, that an
unreasonable risk may be prevented or reduced to a sufficient extent by action taken under a
federal law that is not administered by EPA, EPA must submit a report to the agency
administering that other authority and undertake a statutorily prescribed referral process. EPA
retains the discretion to make this finding in the first instance.

Consistent with TSCA section 9(d), EPA is regularly consulting and coordinating TSCA
activities with OSHA and other relevant federal agencies for the purpose of achieving the
maximum applicability of TSCA while avoiding the imposition of duplicative requirements.
Informed by the mitigation scenarios and information gathered during the risk evaluation and
risk management process, the Agency might propose rules that require risk management
practices that may be already common practice in many or most facilities. Adopting clear,
comprehensive regulatory standards will foster compliance across all facilities (ensuring a level
playing field) and assure protections for all affected workers, especially in cases where current
OSHA standards may not apply or be sufficient to address the unreasonable risk. EPA
appreciates the suggestion to formalize a consultation process with OSHA, as well request for
transparency regarding such consultations. EPA will continue to coordinate with OSHA and
other relevant federal agencies during TSCA risk evaluation and risk management activities and
expects to refine its consultation process as the Agency conducts additional risk evaluations and
risk management rulemakings. The results of any consultation with OSHA, as well as EPA's
rationale for proposed risk management requirements, including consideration of the OSHA
hierarchy of controls, will be reflected in the proposed rule to address the unreasonable risk
presented by PCE.

28


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

The public will have an opportunity to comment on the proposed regulatory action, and EPA will
consider such public comments and any additional information before finalizing the rulemaking.

Section 5.2.3 - OSHA requirements and industry best practices

An industry trade organization (0120) provided several suggestions for how EPA could address
the protection of workers as a PESS including: considering other ways to address concerns about
the population of workers not covered by OSHA standards, developing risk evaluations that do
not assume that PPE is either always or never used in the workplace, working with OSHA during
the scoping phase and discussing improved enforcement of OSHA requirements, considering the
European approach to COUs for the workplace, and more.

EPA RESPONSE:

For purposes of making the TSCA unreasonable risk determination, it is inappropriate to assume
as a general matter that industry best practices are consistently and always properly applied or
that all facilities have adopted these practices. Once EPA has determined that a chemical
substance presents an unreasonable risk, EPA is required to address the identified unreasonable
risk through rulemaking. EPA intends to consider current best workplace practices as it develops
TSCA section 6(a) risk management action to address the unreasonable risk determined in the
PCE risk evaluation, for instance to help inform EPA's assessment of the feasibility and efficacy
of different risk management options. Information on the best workplace practices could also
include information from other countries, such as the European approach mentioned by the
commenters.

As a general matter, when undertaking risk management actions, EPA intends to strive for
consistency with applicable OSHA requirements and industry best practices, including
appropriate application for the hierarchy of controls, to the extent that the requirements, controls,
and practices eliminate the identified unreasonable risks. Informed by the mitigation scenarios
and information gathered during the risk evaluation and risk management process, the Agency
might propose rules requiring risk management practices that may be already common practice
in many or most facilities. Adopting clear, comprehensive regulatory standards will foster
compliance across all facilities (ensuring a level playing field) and assure protections for all
affected workers. EPA will undertake a separate public notice and comment period as part of the
TSCA section 6(a) risk management rulemaking for PCE and will consider public comments and
any additional information before finalizing the rulemaking. Consistent with TSCA section 9(d),
EPA is consulting and coordinating TSCA activities with OSHA and other relevant federal
agencies for the purpose of achieving the maximum applicability of TSCA while avoiding the
imposition of duplicative requirements. Consultation with other relevant federal agencies is also
required during the risk evaluation process under EPA's implementing regulations at 40 CFR
702.39.

As required by TSCA, when conducting risk evaluations, EPA identifies relevant PESS, and
Section 2.4.4.1 of the December 2020 PCE Risk Evaluation describes workers and occupational
non-users, including male and female workers of reproductive age, as PESS. Notwithstanding

29


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

the analysis done for PCE, EPA acknowledges the suggestions by several commenters to identify
workers as a PESS for future risk evaluations and encourages the commenters to submit
chemical-specific comments on PESS to assist during future risk evaluations' comment periods.

Section 5.2.4 - Other comments regarding determination of unreasonable risk not
assuming PPE or other mitigations measures are in place

An advocacy organization (0125) stated that, while EPA determined that it would be
inappropriate to include the assumption of PPE use for determining whether there is an
unreasonable risk, the Agency stated that it would consider the use of PPE in the risk evaluation
to help inform risk management decision. The organization stated that they view this as an
unsupportable approach. The commenter stated that TSCA prohibits EPA from considering costs
or other nonrisk factors in its risk evaluations. The commenter said that in addition to the fact
that risk management is not part of the risk assessment paradigm, for EPA to include risk
mitigation factors in the risk determination would improperly conflate risk management in TSCA
section 6(a) with the risk determination of TSCA section 6(b). Also, for the Agency to
incorporate certain risk mitigation actions into its risk evaluation and determination would
conflict with the TSCA section 26 requirement that EPA use the best available science. The
commenter concluded that EPA should not consider selected facilities' practices or regulatory
requirements to determine worker risk and should recognize the limitations of using such
information for risk management, as the degree of efficacy can vary depending on the facility.
Similarly, an advocacy group (0132) cautioned EPA against treating PPE as a best practice in
selecting risk management options.

An industry trade organization (0129) said there will likely be a delay of years between when the
Agency publishes the final risk evaluation and when the Agency publishes the final risk
management actions that take into account PPE. The commenter expressed concern for the
workplace and the potential confusion the final risk determination could cause in this interim
period. The commenter suggested that EPA incorporate a table for industrial and commercial
uses that identifies whether there is an unreasonable risk without PPE and with known PPE,
which would facilitate the submission of more robust and targeted comments during risk
management, and effectively communicate the risk to stakeholders.

An industry trade organization (0131) stated that in the December 2020 risk evaluation, EPA did
not identify employees not covered by OSHA requirements as a PESS in the final risk evaluation
for PCE. The commenter said that such persons, however, are also unlikely to be exposed to the
neat substances or to the substances at elevated concentrations and are therefore not reasonably
foreseen. Though EPA seeks to ensure it addresses unreasonable risk in all occupational
conditions of use, it must first evaluate risk presented to this category of employees under the
intended, known, or reasonably foreseen conditions of use. The commenter also stated that EPA
does not explain how the proposal will be consistent with the requirement under TSCA section
9(d) that EPA must avoid the duplication of Federal action against unreasonable risk. The
commenter stated that, though EPA states that it intends to consult and coordinate with OSHA,
EPA also assumes that because current OSHA standards do not extend to all workplaces,

30


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

regulating the substances under TSCA section 6(a) will appropriately address unreasonable risk
in all occupational settings. However, as the commenter stated, EPA should also consider that
not all workers employed in regulated facilities are regulated by TSCA. Further, the commenter
stated that EPA should evaluate unreasonable risks to workers not covered by OSHA standards
and consider necessary protections for this category of workers separately.

An advocacy organization (0125) expressed support for EPA's proposal to discard the
assumptions of existing worker protection, including use of PPE during risk determinations.
However, the commenter took issue with EPA's statement in the revised risk determination that
in some risk evaluations, levels of risks to workers may be evaluated with and without OSHA
requirements and industry best practices scenarios that are clearly articulated to the Agency. The
advocacy organization stated its view that EPA should not use worker mitigation
characterizations and scenarios during risk evaluation, EPA should also recognize that there are
limitations to such information during risk management.

EPA RESPONSE:

EPA believes it is appropriate to evaluate the levels of risk present in scenarios considering
applicable OSHA requirements, as well as scenarios considering industry or sector best practices
for industrial hygiene because such evaluation can help inform potential risk management
actions (i.e., by informing EPA's assessment of the feasibility and efficacy of different risk
management options). However, as commenters note, for purposes of making the TSCA
unreasonable risk determination, it is inappropriate to assume as a general matter that industry
best practices are consistently and always properly applied or that all facilities have adopted
these practices. Once EPA has determined that a chemical substance presents an unreasonable
risk, EPA is required to address the identified unreasonable risk of injury to health determined in
the PCE risk evaluation and revised risk determination, including unreasonable risk driven by
acute and chronic non-cancer and cancer effects. In response to the comment (0131) that EPA
did not identify employees not covered by OSHA requirements as a PESS, EPA notes that in the
December 2020 Risk Evaluation for PCE, EPA identified workers and ONUs (including men and
women of reproductive age, and adolescents), among others, as PESS (see Section 2.4.4 and
Table 4-125), regardless of whether the employees would be covered by OSHA requirements.

The final risk evaluation already includes an exposure analysis with and without PPE. Table 4-
125 in the final risk evaluation presents risk estimates for each condition of use with and without
PPE. EPA has made no changes to this analysis. Therefore, removing the assumption that
workers always and appropriately wear PPE when making the unreasonable risk determination
does not create a need for new analysis. The finalized revision to the risk determination clarifies
that EPA does not rely on the assumed use of PPE when making the risk determination for the
whole substance (section 5.1). Overall, 60 conditions of use drive the PCE whole chemical
unreasonable risk determination due to risks identified for human health.

EPA understands that there could be occupational safety protections in place at workplace
locations; however, not assuming use of PPE reflects EPA's recognition that unreasonable risk
may exist for subpopulations of workers that may be highly exposed because they are not
covered by OSHA standards, or their employers are out of compliance with OSHA standards, or

31


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

because many of OSHA's chemical-specific permissible exposure limits largely adopted in the
1970's are described by OSHA as being "outdated and inadequate for ensuring protection of
worker health,"7 or because the OSHA PEL alone may be inadequate to protect worker health, or
because EPA finds unreasonable risk for purposes of TSCA notwithstanding OSHA
requirements. Regarding the commenter's assertion that EPA should consider that not all
industrial facilities are regulated by TSCA, EPA notes that under TSCA sections 6(a)(2) and (5),
EPA has the authority to prohibit or restrict the manufacture, processing, distribution in
commerce, or manner or method of commercial use of a chemical substance or mixture, with the
definition of chemical substance provided in TSCA section 3.

As a general matter, when undertaking risk management actions, EPA intends to strive for
consistency with applicable OSHA requirements and industry best practices, including
appropriate application of the NIOSH hierarchy of controls, to the extent that the requirements,
controls, and practices eliminate the identified unreasonable risk. Informed by the mitigation
scenarios and information gathered during the risk evaluation and risk management process, the
Agency might propose rules requiring risk management practices that may be already common
practice in many or most facilities. Adopting clear, comprehensive regulatory standards will
foster compliance across all facilities (ensuring a level playing field) and assure protections for
all affected workers. Consistent with the statutory requirements of TSCA section 6(a), EPA will
propose risk management action to the extent necessary so that PCE no longer presents an
unreasonable risk. Also, consistent with TSCA section 9(d), EPA is consulting and coordinating
TSCA activities with OSHA, NIOSH, and other relevant federal agencies for the purpose of
achieving the maximum applicability of TSCA while avoiding the imposition of duplicative
requirements. In the proposed rules under TSCA section 6(a), EPA will explain the consultation
and coordination with other appropriate Federal executive departments and agencies, including
OSHA, as required by TSCA section 9(d). EPA will undertake a separate public notice and
comment period as part of the TSCA section 6(a) risk management rulemaking for PCE, and will
consider public comments and any additional information before finalizing the rulemaking.

In response to the commenter's concern (0125) that EPA is incorporating risk management
actions into the risk evaluation, the Agency clarifies that EPA's final risk determination is
explicit insofar as it does not rely on assumptions regarding the use of PPE in making the
unreasonable risk determination under TSCA section 6, even though some facilities might be
using PPE as one means to reduce worker exposures. As described earlier, the revised
unreasonable risk determination for PCE is based on the peer reviewed risk characterization in
the December 2020 PCE Risk Evaluation, based on reasonably available information pursuant to
TSCA section 26(k) and 40 CFR 702.33, and developed in accordance with TSCA section 26(h)
and (i) to make decisions under TSCA section 6 in a manner consistent with the best available
science and based on the weight of scientific evidence.

Regarding the comment on PPE as a risk management option, EPA notes that information on the
use of PPE as a means of mitigating risk (including public comments received from industry

7 As noted on Occupational Safety and Health Administration. Permissible Exposure Limits - Annotated Tables.
Accessed June 13, 2022. https://www.osha.gov/an.notated-peis.

32


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

respondents about occupational safety practices in use) will be considered during the risk
management phase, as appropriate.

Section 5.2.5 - Permissible exposure limits (PELs)

In response to EPA's statement in the draft revision to the PCE risk determination that the
Agency intends to make its unreasonable risk determination from a baseline scenario that does
not assume compliance with OSHA standards, one commenter (0125) discussed OSHA's PELs.
In expressing support for EPA's proposed assumption, the advocacy organization stated that
OSHA itself has noted that many of its PELs are outdated and inadequate for ensuring protection
of worker health. The commenter concluded that, therefore, even when a company may be in
compliance with an OSHA requirement, its worker protection program may nevertheless result
in unreasonable risks to workers.

The advocacy organization (0125) also commented that in the PCE risk determination, EPA
incorrectly suggests that compliance with OSHA PELs may protect against unreasonable risks.
The commenter stated its view that this is misleading since, in determining risk under TSCA,
EPA is directed to not consider cost or other nonrisk factors; in contrast, in setting a PEL, OSHA
must consider technological and economic feasibility. In addition, a greater degree of risk is
acceptable under the OSH Act (significant risk) than under TSCA (unreasonable risk). The
commenter concluded that an unreasonable risk under TSCA would not likely be considered a
significant risk under the OSH Act and, therefore, it is not clear how EPA could envision that
compliance with the OSHA standards would consistently protect against unreasonable risks.

EPA RESPONSE:

OSHA's mission is to ensure that employees work in safe and healthful conditions. The OSH Act
establishes requirements that each employer comply with the General Duty Clause of the Act (29
U.S.C. 654(a)), as well as with occupational safety and health standards issued under the Act.
The General Duty Clause of the OSH Act requires employers to keep their workplace free from
recognized hazards that are causing or are likely to cause death or serious physical harm to
employees. The General Duty Clause is cast in general terms, and does not establish specific
requirements like exposure limits, PPE, or other specific protective measures that EPA could
potentially consider when developing its risk evaluations or risk management requirements.
Because the requirements and application of TSCA and OSHA regulatory analyses differ, it is
appropriate that EPA conduct risk evaluations and, where it finds unreasonable risk to workers,
develop risk management requirements for chemical substances that OSHA also regulates, and it
is understood that EPA's findings and requirements may sometimes diverge from OSHA's. It is
appropriate, however, that EPA consider the chemical standards that OSHA has already
developed, so as to limit the compliance burden to employers by aligning management
approaches required by the agencies, where alignment will adequately address unreasonable risk
to workers.

EPA conducts baseline assessments of risk and makes its determination of unreasonable risk
from a baseline scenario that is not based on an assumption of compliance with OSHA standards,
including any applicable exposure limits or requirements for use of respiratory protection or

33


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

other PPE. Making unreasonable risk determinations based on the baseline scenario should not
be viewed as an indication that EPA believes there are no occupational safety protections in
place at any location, or that there is widespread noncompliance with applicable OSHA
standards. Rather, it reflects EPA's recognition that unreasonable risk may exist for
subpopulations of workers that may be highly exposed because they are not covered by OSHA
standards, such as self-employed individuals and public sector workers who are not covered by a
State Plan, or because their employer is out of compliance with OSHA standards, or because
many of OSHA's chemical-specific permissible exposure limits largely adopted in the 1970's are
described by OSHA as being "outdated and inadequate for ensuring protection of worker
health,"8 or because the OSHA PEL alone may be inadequate to protect worker health, or
because EPA finds unreasonable risk for purposes of TSCA notwithstanding existing OSHA
requirements

As a general matter, when undertaking risk management actions, EPA intends to strive for
consistency with applicable OSHA requirements and industry best practices, including
appropriate application of the NIOSH hierarchy of controls, to the extent that the requirements,
controls, and practices address the identified unreasonable risks according to TSCA section 6(a).

Section 5.2.6 - Other comments on OSHA requirements or best practices

An advocacy group (0132) discussed how OSHA and NIOSH manage chemical risks using the
"hierarchy of controls." The advocacy group also stated that some commenters incorrectly stated
that EPA's risk management approach under TSCA is undermining OSHA's worker protection
responsibilities.

In contrast, a chemical manufacturer (0134) stated that they have a well-established and robust
worker protection program in place that follows the hierarchy of controls. The commenter said
that PCE is used in a closed system with engineering controls designed to prevent potential
industrial emissions and exposures. In addition, workers perform activities in short durations
while wearing PPE. In addition, the commenter said that they also perform air sampling
monitoring, implement extensive training for employees, and maintain training records. The
commenter recommended that the risk determination be revised so that it would, as they
describe, accurately reflect exposure, including the use of PPE, under the COU.

Similarly, an industry trade coalition (0137) stated that the chemical synthesis of refrigerants
occurs in a completely closed system where the chlorinated feedstock material is completely
consumed. There is very little exposure, and PPE and emission controls have been in place for
years. The commenter stated that the industry has an exemplary safety record. The commenter
discussed EPA's statement that OSHA rules date back to the 1970s; the commenter reasoned that
if OSHA standards need be updated, OSHA should be asked to update its work as it relates to
these specific compounds.

8 As noted on Occupational Safety and Health Administration. Permissible Exposure Limits - Annotated Tables.
Accessed June 13, 2022. https://www.osha.gov/an.notated-peis.

34


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

An industry trade organization (0122) stated that petroleum refining is regulated under Section
313 of the Emergency Planning and Community Right-to-Know Act, Hazardous Air Pollutant
provisions under the Clean Air Act, Comprehensive Environmental Response Compensation and
Liability Act, National Primary Drinking Water Regulations under the Safe Drinking Water Act,
OSH Act, Chemical Facility Anti-Terrorism Act, and Marine Transportation Security Act. In
addition, petroleum refiners are subject to inspections by EPA, OSHA, Department of
Transportation, Department of Homeland Security, United States Coast Guard, and state
regulatory authorities. The commenter stated that OSHA safety statistics continually demonstrate
that the refining industry is among the safest of all manufacturing sectors. In addition, petroleum
refiners have well-defined and explicit operating procedures that very often exceed regulatory
standards.

EPA RESPONSE:

Consistent with TSCA section 9(d), EPA is consulting and coordinating TSCA activities with
OSHA and other relevant federal agencies for the purpose of achieving the maximum
applicability of TSCA while avoiding the imposition of duplicative requirements. Consultation
with other relevant federal agencies is also required during the risk evaluation process under
EPA's implementing regulations at 40 CFR 702.39.

When undertaking unreasonable risk determinations as part of TSCA risk evaluations, however,
EPA does not believe it is appropriate to assume as a general matter that an applicable OSHA
requirement or industry practice related to PPE use is consistently and always properly applied.
Mitigation scenarios included in the EPA risk evaluation (e.g., scenarios considering use of
various PPE) likely represent what is happening already in some facilities, and EPA appreciates
the commenter providing information on how in their facility they utilize the hierarchy of
controls as part of a worker protection program (0134). However, the Agency cannot assume that
all facilities have adopted these practices for the purposes of making the TSCA risk
determination.

Additionally, regarding the information the commenter provided on petroleum refining (0122),
EPA appreciates the commenter highlighting that these facilities are regulated by EPA and other
agencies under several statutes. Under TSCA, EPA has identified that this condition of use drives
the unreasonable risk from PCE, based on worker exposures. (EPA notes that in the December
2020 Risk Evaluation, EPA identified unreasonable risk for this condition of use even when use
of PPE was assumed, due to dermal exposures). EPA will be considering information regarding
industry best practices for industrial hygiene in the development of the risk management rule.
EPA's consideration of the information received will be explained in the proposed rulemaking
under TSCA section 6(a) and EPA will consider public comments and any additional
information before finalizing the rulemaking.

EPA notes that consistent with the statutory requirements of TSCA section 6(a), EPA will
propose risk management actions to the extent necessary so that PCE no longer presents an
unreasonable risk. EPA expects to focus its risk management action on the conditions of use that
drive the unreasonable risk, including in chemical manufacturing and petroleum refining. The
public will have an opportunity to comment on the proposed regulatory action, and EPA will

35


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

consider such public comments and any additional information and the proposed regulatory
action before finalizing the rulemaking. EPA emphasizes the Agency considers all regulatory
mechanisms under TSCA section 6(a) in addressing unreasonable risk identified in the revised
risk determination.

EPA encourages the commenters to submit specific comments about worker protection
measures, including engineering controls (such as closed systems) and administrative controls,
during the future public comment period for the forthcoming notice of proposed rulemaking for
risk management of PCE. As part of that rulemaking, EPA will consider reasonably available
information on worker protection measures, including information provided by regulated
industries.

Section 6 - Unreasonable risk determination

An advocacy organization (0125) stated its view that EPA should not treat workers differently
than the general population when making an unreasonable risk determination for PCE under
TSCA section 6(b)(4), because such differential treatment is based on nonrisk factors and is thus
prohibited under TSCA section 6(b)(4). Specifically, the advocacy organization stated that in the
risk evaluation for PCE, EPA identified unreasonable risks for cancer from chronic inhalation
and dermal exposure to PCE to workers and ONUs, and the Agency's determinations of
unreasonable risk were based on different cancer benchmarks depending on the subpopulation.
The commenter stated that EPA's bifurcated approach to workers vs. everyone else for cancer
risks is illogical, inconsistent, and unsupported by TSCA. The advocacy organization further
stated that workers often face higher risks than the general population, making a less protective
standard particularly unjustified.

EPA RESPONSE:

EPA evaluates exposures to workers, occupational non-users, consumer users, and bystanders
using reasonably available monitoring and modeling data for exposures to PCE as required under
TSCA section 6(b). Certain assumptions about exposure are taken into account when considering
what constitutes an unreasonable risk presented to the general population and subpopulations
(e.g., workers). A consideration of the exposure circumstances for workers compared to those of
the general population illustrates that it is appropriate to consider a range of benchmarks to
inform risk management approaches. For example, in 2017 when EPA's Office of Water updated
the Human Health Benchmarks for Pesticides, the benchmark for a "theoretical upper-bound
excess lifetime cancer risk" from pesticides in drinking water was identified as 1 in 1,000,000 to
1 in 10,000 over a lifetime of exposure.9 Similarly, EPA's approach under the Clean Air Act to
evaluate residual risk and to develop standards is a two-step approach that "includes a
presumptive limit on maximum individual lifetime [cancer] risk (MIR) of approximately 1 in 10
thousand" and consideration of whether emissions standards provide an ample margin of safety
to protect public health "in consideration of all health information, including the number of

9 EPA. Human Health Benchmarks for Pesticides: Updated 2017 Technical Document (pp.5). (EPA 822-R -17 -
001). Washington, DC: U.S. Environmental Protection Agency, Office of Water. January 2017.
https://www.epa.gov/sites/production/files/2015-10/documents/hh-benchmarkstechdoc.pdf).

36


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

persons at risk levels higher than approximately 1 in 1 million, as well as other relevant factors"
(54 FR 38044, 38045, September 14, 1989).

The cancer risk estimates in the PCE risk evaluation represent the incremental increase in
probability of an individual in an exposed population developing cancer over a lifetime
following exposure to PCE. As such, EPA calculated cancer risk estimates from PCE exposure
for workers and occupational non-users under an 8-hour time weighted average (TWA) and a
lifetime average daily concentration (LADC). The calculation of the cancer risk (i.e., the analysis
of the cancer dose response data) is a scientific analysis. It is typical practice at EPA to calculate
a range of cancer risks from lxlO"4 to lxlO"6. However, the benchmark used in risk management
is a policy choice that considers the scientific analysis. As such, the benchmark value for risk
management of cancer findings is not a bright line and appropriately EPA has discretion. Though
EPA has the discretion to make an unreasonable risk determination for any chemical substance
based on other benchmarks as appropriate (such as lxlO"6 depending on the subpopulation
exposed), lxlO"4 was consistently applied as the benchmark for the cancer risk to individuals in
industrial and commercial workplaces for PCE. The lxlO"4 for cancer risk to workers is
consistent with the NIOSH cancer guidance for occupational exposures from 2017. Further
information related to this is in section 5.2.3 of the final revised risk determination and sections
2.4.1.3 and 4.2.1 of the December 2020 PCE Risk Evaluation.

In each risk evaluation under TSCA, EPA determines whether a chemical substance presents an
unreasonable risk of injury to health or the environment under the conditions of use. EPA makes
the unreasonable risk determination without the consideration of costs or other non-risk factors.
In making the unreasonable risk determination, EPA considers relevant risk-related factors,
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 potentially exposed or susceptible subpopulation
or PESS); the severity of hazard (including the nature of the hazard, the irreversibility of the
hazard); and uncertainties. EPA also takes into consideration the Agency's confidence in the data
used in the risk estimate. This includes an evaluation of the strengths, limitations, and
uncertainties associated with the information used to inform the risk estimate and the risk
characterization. This approach is in keeping with EPA's obligation under TSCA section 26(h) to
base its decisions on the best available science, and the Agency's final rule, Procedures for
Chemical Risk Evaluation Under the Amended Toxic Substances Control Act (82 FR 33726,

July 20, 2017).

Section 7 - Conditions of use that drive the unreasonable risk determination
Section 7.1 - Processing (including recycling)

An industry trade coalition (0137) commented that the use of chlorinated chemicals, including
PCE, as feedstock in closed systems to produce fluorinated substances is important and stands
apart from the direct applications and use of these substances as solvents or process aids and
should thus be treated differently. The commenter added that these feedstock materials, including

37


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

PCE, are critical to compliance with the American Innovation and Manufacturing Act of 2020
(the AIM Act). The commenter provided some examples of critical uses of products made from
feedstock substances, including PCE, such as in semiconductor and other electronics
applications, as well as defense, medical products, foam insulation and fire protection, and heat
pumps.

Similarly, a chemical manufacturer (0134) explained that it uses PCE as a feedstock to
domestically manufacture a product used in various market applications, primarily as a
refrigerant and blowing agent. The chemical manufacturer stated that the use of this product in
making low GWP refrigerant blends is important to achieving the GWP phase down goals of the
AIM Act and the Biden Administration's climate objectives. The commenter warned that if this
use is deemed unreasonable, the production of these next generation products could move away
from domestic manufacture, shifting reliance on foreign sourced manufacturers, primarily China,
who do not comply with EPA and OSHA standards.

EPA RESPONSE:

EPA appreciates the comments (0137, 0134) highlighting the overlap of the upcoming TSCA
section 6(a) risk management rule for PCE with EPA's actions under the American Innovation
and Manufacturing Act of 2020. EPA will consider this context during the development of the
upcoming proposed risk management rule, which will be available for public comment. EPA will
undertake a separate public notice and comment period as part of the TSCA section 6(a) risk
management rulemaking for PCE and will consider public comments and any additional
information before finalizing the rulemaking.

Section 7.2 - Industrial and commercial use

A product manufacturer (0133) expressed concern that the proposed rule could eventually lead to
EPA discontinuing the use of PCE. The commenter stated that PCE is currently used in processes
for fabricating aluminum aircraft fuselages and wings, and the fabrication process makes
aerostructures resistant to micro-cracking, which can occur throughout the life of the aircraft,
thereby increasing the safety of the overall aircraft. The commenter added that the fabrication
process also reduces the weight of aerostructures, thereby increasing their efficiency and
lowering emissions. The product manufacturer stated its view that PCE is an essential part of this
fabrication process; without it, the aerospace and defense industries would be unable to maintain
the acceptable level of safety and efficiency of its aerostructures. The commenter went on to
state that, for more than a decade, aerospace companies have been researching alternatives and
replacement options for PCE, and thus far, there have been no chemicals identified that are less
harmful.

An industry trade organization (0122) discussed the use of PCE as a catalyst regenerator in
petroleum refineries. Specifically, the commenter stated that PCE is used as a catalyst
regenerator in isomerization and catalytic reforming processes at petroleum refineries; the
resulting products from these processes, called isomerate and reformate, go into gasoline blends
that make up approximately 45% of the gasoline pool in the U.S. The commenter stated its view
that PCE is the safest catalyst activator and regenerator for spent catalyst during normal
operating conditions; the alternatives are either less efficient or more hazardous. The industry

38


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

trade organization discussed how PCE is used in continuous, closed processes and subject to
multiple engineering controls to prevent exposures for this COU, and provided detailed
information on the safety record of petroleum refining.

EPA RESPONSE:

EPA appreciates the information provided by each of the commenters (0133 and 0122) regarding
their particular use of PCE. As suggested by several commenters, EPA will be considering the
information in the development of the risk management rule. EPA's consideration of the
information received will be explained in the proposed rulemaking under TSCA section 6(a) and
EPA will consider public comments and any additional information before finalizing the
rulemaking.

As stated in the revised unreasonable risk determination for PCE, while not appropriate as the
basis for the unreasonable risk determination, EPA believes it is appropriate to evaluate the
levels of risk present in scenarios considering applicable OSHA requirements, as well as
scenarios considering industry or sector best practices for industrial hygiene because such
evaluation can help inform potential risk management actions (i.e., by informing EPA's
assessment of the feasibility and efficacy of different risk management options). EPA encourages
the commenters to submit specific comments about worker protection measures, including
engineering controls and administrative controls, during the future public comment period for the
forthcoming PCE risk management rule. As part of that rulemaking, EPA will consider
reasonably available information on worker protection measures, including information provided
by regulated industries.

Section 8 - Comments regarding conditions of use that do not drive the unreasonable risk
determination

An industry trade organization (0129) commented that there is no indication in the current
proposal how COUs that do not pose an unreasonable risk will be addressed. The commenter
stated its view that this creates uncertainty in the marketplace and may lead to unnecessary
supply disruptions that could have been avoided. In addition, the industry trade organization
stated that it is not clear how this would impact the preemptive effects of TSCA. The commenter
recommended that the Agency clearly indicate how EPA intends to approach COUs that do not
pose an unreasonable risk throughout the rest of the risk evaluation process.

An advocacy organization (0125) expressed support for EPA's approach, in that the Agency is
not limited to regulating the precise activities that drive unreasonable risk and for example, may
choose to regulate upstream COUs, such as processing and distribution in commerce, to avoid
downstream unreasonable risk drivers, such as consumer use, even if the upstream activities are
not unreasonable risk drivers.

The advocacy organization (0125) recommended that EPA re-evaluate its risk determination for
distribution in commerce considering exposures from spills and leaks, as well as its assumption
that compliance with existing regulations for the transportation of hazardous materials will not
result in an unreasonable risk. The advocacy organization stated its view that spills and leaks can
result in significant exposures and are not infrequent, unpredictable events; thus, EPA should not
have excluded spills and leaks from the risk evaluation. In addition, the commenter stated that

39


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

EPA's assumption that compliance with existing regulations for the transportation of hazardous
materials will not result in an unreasonable risk is without rationale. The advocacy organization
recommended that EPA re-evaluate its risk determination for distribution in commerce
considering exposures from spills and leaks and explain its assumption that compliance with
existing regulations for the transportation of hazardous materials will not result in an
unreasonable risk.

EPA RESPONSE:

EPA understands there is strong public interest in learning how unreasonable risk from PCE will
be addressed, including potential impacts on specific conditions of use, including those that do
not drive the unreasonable risk for PCE. Consistent with the statutory requirements of TSCA
section 6(a), EPA will by rule apply one or more of the risk management options in TSCA
section 6(a) to the extent necessary so that PCE no longer presents an unreasonable risk. EPA
expects to focus its risk management action on the conditions of use that drive the unreasonable
risk. However, as one commenter suggests (0125), it should be noted that, under TSCA section
6(a), EPA is not limited to regulating the specific activities found to drive unreasonable risk and
may select from among a suite of risk management requirements in section 6(a) related to
manufacture (including import), processing, distribution in commerce, commercial use, and
disposal as part of its regulatory options to address the unreasonable risk. EPA agrees with the
commenter that, as a general example, EPA may regulate upstream activities (e.g., processing,
distribution in commerce) in order to address downstream activities (e.g., consumer uses) driving
unreasonable risk even if the upstream activities do not drive the unreasonable risk.

Regarding preemption, as described earlier in this document, TSCA section 18(c)(3) defines the
scope of federal preemption with respect to any final rule EPA issues under TSCA section 6(a).
That provision provides that federal preemption of "statutes, criminal penalties, and
administrative actions" applies 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 [TSCA
section 6(a)]." EPA reads this to mean that states are preempted from imposing requirements
through statutes, criminal penalties, and administrative actions relating to any "hazards,
exposures, risks, and uses or conditions of use" evaluated in the final risk evaluation and
informing the risk determination that EPA addresses in the TSCA section 6(a) rulemaking. For
example, federal preemption applies even if EPA does not regulate in that final rule a particular
COU, as long as that COU was evaluated in the final risk evaluation.

With respect to the comment related to distribution in commerce, spills, and leaks (0125), as in
the December 2020 risk evaluation, EPA's final revised risk determination maintains that
distribution in commerce of PCE is the transportation associated with the moving of PCE in
commerce. EPA has determined that unreasonable risk to workers and ONUs is not driven by the
activities associated with this COU, which consists of the actual moving of the chemical in
commerce. The loading and unloading activities are associated with other conditions of use (e.g.,
processing). EPA assumed limited emissions from the actual transportation of chemicals (i.e.,
neither persons nor the environment would be exposed to the chemical in the transportation
container), given the fact that these chemicals are transported according to existing hazardous
materials transportation rules. In the PCE revised unreasonable risk determination, EPA
recognizes that, due to the practical realities of how chemicals are transported and the fact that

40


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

the condition of use is limited to the movement of the chemical in commerce, exposures to
workers are expected to be minimal. Spills and leaks generally were not included within the
scope of the first 10 TSCA risk evaluation, including for PCE. Further information on the
assessment of spills and leaks in the risk evaluation are included in the Summary of External
Peer Review and Public Comments and Disposition for Perchloroethylene (PCE) (EPA-HQ-
OPPT-2019-0502-0059).

Based on the limited emissions from the transportation of chemicals, EPA has determined that
distribution in commerce of PCE does not drive the unreasonable risk determination for PCE.

Section 9 - Comments regarding EPA's withdrawal of the associated orders

An industry trade organization (0135) requested that EPA not withdraw the order for the PCE
COUs that were found not to present an unreasonable risk under the December 2020 risk
evaluation. This commenter requested that EPA not withdraw the existing associated orders to
avoid regulatory issues in states which promulgate risk management rules before EPA finalizes
their federal rule and create preemption concerns over state and federal requirements. The
industry trade organization requested that EPA keep the associated orders in place until a second
round of risk evaluations for the ten Work Plan chemicals have been completed to provide
additional certainty throughout the process and until new risk management rules are in place.

EPA RESPONSE:

EPA does not plan to conduct a second risk evaluation on PCE. EPA is issuing a final revised
unreasonable risk determination for the PCE evaluation after consideration of the public
comments received on the draft. For purposes of TSCA section 6(i), EPA is making a risk
determination on PCE as a whole chemical. Under the revised approach, the "whole chemical"
risk determination for PCE supersedes the no unreasonable risk determinations for PCE that
were premised on a condition of use-specific approach to determining unreasonable risk and also
contains an order withdrawing the TSCA section 6(i)(l) order in Section 5.4.1 of the December
2020 Risk Evaluation for PCE. Consistent with the statutory requirements of TSCA section 6(a),
the Agency will propose risk management actions to the extent necessary to address the
unreasonable risk presented by PCE.

TSCA section 18(c)(3) defines the scope of federal preemption with respect to any final rule
EPA issues under TSCA section 6(a). That provision provides that federal preemption of
statutes, criminal penalties, and administrative actions applies to the hazards, exposures, risks,
and uses or conditions of use of the chemical substance included in any final action the
Administrator takes pursuant to TSCA section 6(a). EPA reads this to mean that states are
preempted from imposing requirements through statutes, criminal penalties, and administrative
actions relating to any hazards, exposures, risks, and uses or conditions of use evaluated in the
final risk evaluation and informing the risk determination that EPA addresses in the TSCA
section 6(a) rulemaking. For example, federal preemption applies even if EPA does not regulate
in that final rule a particular COU, as long as that COU was evaluated in the final risk evaluation.

41


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

Section 10 - Comments on EPA's screening approach to assess risks from air and water
pathways

An industry trade organization (0120) commented that any supplemental analyses for the risk
evaluations that have the potential to influence the risk management rules (including a screening
approach to assess potential risks from the air and water pathways) must be made available for
public comment.

A comment submitted by several state and local government agencies and organizations (0124)
encouraged EPA to consider all exposure pathways for current and future TSCA risk evaluations,
including areas that are, or could be, regulated under other statutes, such as the Clean Air Act,
Clean Water Act, Safe Drinking Water Act, and Resource Conservation and Recovery Act. The
commenter stated its view that EPA's past exclusion of those exposure pathways for the first ten
chemicals was concerning and expressed support for the reevaluation of those findings. The state
government agency encouraged close coordination of TSCA regulatory processes with other
related processes, such as regulation of hazardous air pollutants. The commenter also suggested
that EPA establish an improved screening approach to assess exposures and risks for fenceline
communities and other PESS.

EPA RESPONSE:

As described in the Federal Register Notice, the PCE risk determination has been revised to
reflect announced policy changes to help ensure the public is protected from unreasonable risks
from chemicals in a way that is supported by science and the law. Separately, EPA is conducting
a screening approach to assess risks from the air and water pathways for several of the first 10
chemicals, including PCE. In January 2022, EPA released the TSCA Screening Level Approach
for Assessing Ambient Air and Water Exposures to Fenceline Communities for public comment
and peer review; in March 2022, EPA held a public virtual meeting of the Science Advisory
Committee on Chemicals (SACC) to peer review the approach. EPA presented Version 1.0 of a
screening level methodology for assessing potential air and water pathway chemical exposures to
fenceline communities. Along with presenting this methodology, EPA also presented results of
applying the screening methodology (case studies) to 1-brompropane (air pathway), n-
methylpyrrolidone (water pathway), and methylene chloride (air and water pathways). The
proposed screening level methodology went through a public comment period and peer review
(by the SACC) for comments on the proposed methodology as well as recommended revisions or
improvements to the methodology. The SACC delivered its report in May 2022. Following
public comment and peer review, EPA is reviewing comments, recommendations, and
improvements; and modifying the fenceline methodology, as appropriate. EPA expects to
describe its findings regarding the chemical-specific application of this screening-level approach
in the forthcoming proposed TSCA section 6(a) risk management rule for PCE.

EPA notes that the Agency engages in intra-agency review on TSCA risk evaluations, as well as
coordination within EPA to promote the type of coordination the commenter describes. EPA also
notes the opportunities for public engagement throughout the risk evaluation process and
appreciates the comments from state government agencies and others received to date.

42


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

Section 11 - Other comments related to the draft revision of the risk determination
Previously submitted comments

An advocacy organization (0126, 0138) stated that it submitted comments and presented
testimony to the SACC in response to EPA's announcement that it was seeking public input on
the initial draft risk evaluation of PCE under TSCA. The commenter provided a link to its
previous comments and stated that, in these comments, the advocacy organization raised
significant concerns about the initial draft risk evaluation based on issues including but also in
addition to those addressed in EPA's revised draft risk determination for PCE under TSCA. A
commenter (0121) requested that EPA incorporate by reference their comments on the HBCD
and methylene chloride revised risk determinations into this docket.

EPA RESPONSE

EPA appreciates comments provided to the SACC in May 2020. Those comments are responded
to in full in the docket EPA-HQ-OPPT-2019-0502. The revised unreasonable risk determination
for PCE is based on the peer reviewed risk characterization in the December 2020 Risk
Evaluation, based on reasonably available information pursuant to TSCA section 26(k) and 40
CFR 702.33, and developed in accordance with TSCA section 26(h) and (i) to make decisions
under TSCA section 6 in a manner consistent with the best available science and based on the
weight of scientific evidence. The policy changes described in the Federal Register Notice
announcing the availability of the draft revised risk determination for PCE do not amend or
impact the underlying data and analysis presented in the risk characterization of the December
2020 PCE Risk Evaluation. The policy changes do not impact the characterization of risk
estimates by condition of use (summarized in Section 4 of the final risk evaluation), or the
occupational exposures to workers and ONUs (summarized in Section 2.4 of the final risk
evaluation). EPA will proceed expeditiously to mitigate identified unreasonable risk through
rulemaking as required by TSCA section 6(a).

Regarding the request that EPA incorporate previous comments on separate actions (0120), EPA
has considered the commenter's previously submitted comments on the draft revised risk
determinations for HBCD and methylene chloride that were incorporated into its comments on
the PCE draft revised risk determination, and has responded in this document to the general
themes raised by the commenter therein.

Risk Management

An industry trade organization (0135) requested that EPA identify a de minimis level for PCE
below which EPA has no reasonable basis to conclude that there is an unreasonable risk and
recommended that EPA establish a de minimis level for chemicals in articles and mixtures based
on a reasonable potential for exposure. The commenter stated that EPA has recently recognized
the practicality of de minimis thresholds in its "Long-Chain Perfluoroalkyl Carboxylate and
Perfluoroalkyl Sulfonate Chemical Substances; Significant New Use Rule; Supplemental
Proposal" and stated its view that a standard default de minimis of 0.1% would allow EPA to
focus on major sources and would allow for more effective use of the automotive industry's long-

43


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

term investment in its internal IMDS system. The commenter said that EPA could also use a data
driven approach to establish higher threshold levels if appropriate.

EPA RESPONSE

EPA will consider relevant information in the development of the risk management rule,
including the suggestion (0135) for identifying a de minimus level (though EPA notes that the
commenter incorrectly implies that EPA proposed a de minimus threshold in the cited
supplemental proposed Significant New Use Rule). EPA will undertake a separate public notice
and comment period as part of the proposed TSCA section 6(a) risk management rulemaking for
PCE and will consider public comments and any additional information before finalizing the
rulemaking.

Other

A comment submitted by several state and local government agencies and organizations (0124)
commented that many state and local governments are working actively to protect human health
and the environment through toxic chemical policies and regulations; voluntary business
assistance programs; disposal, cleanup and recycling programs; and other pollution prevention
and toxics reduction activities. The commenter expressed appreciation for EPA's work under
TSCA, since strong implementation of TSCA has the potential to support these state and local
programs. The commenter requested that EPA proactively expand its TSCA consultations with
technical staff at state and local governments, particularly those with active toxics reduction,
pollution prevention, and safer alternatives programs and those that have already executed rules
to protect their local communities from chemical risks.

The comment submitted by several state and local government agencies and organizations (0124)
provided the following recommendations for the TSCA risk evaluation and risk management
processes:

•	Establish a process that expands EPA's required federalism consultations to create a more
meaningful and substantive dialogue with state, local and Tribal governments on its
TSCA risk evaluations. EPA should directly consult with state and local governments
early in the risk evaluation process to ensure its scoping for risk evaluation casts a broad
net and is comprehensive in considering all specific and local uses, hazards, exposures,
and PESS.

•	All sources of exposure must be considered, including sources from products (including
articles), the workplace, manufacturing and processing facilities, recycling and disposal,
and legacy sources. EPA should evaluate cumulative and aggregate exposures to
individuals and communities across multiple pathways, such as air, water, food, and
dermal contact, in work and living settings rather than considering each pathway in
isolation.

•	Risk assessment and risk management rules must fully consider, address, and eliminate
impacts on key at-risk or PESS.

44


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

•	EPA cannot fully evaluate safety and should not make determinations of no unreasonable
risk when there is a lack of chemical use, exposure, human health, or eco-toxicological
data. When gaps exist, EPA must fully utilize its TSCA authorities to fill data gaps.

•	Risk management regulations that could preempt existing state or local statutes and
regulations should be executed with extreme caution if they are not equally protective in
effect and scope.

•	Create systems to support shifts to safer alternatives, prevent use of regrettable substitutes
that are also hazardous, and support small businesses in those transitions through existing
TCSA authority or through seeking additional authority or resources.

•	Disposal and other end-of-life considerations should be fully addressed in each risk
management rule, including occupational safety and impacts from pollution at legacy
disposal sites, manufacturing sites, household hazardous wastes, and wastewater and
storm water discharges.

An industry trade organization (0136) expressed support for the goal of implementing TSCA to
eliminate unreasonable human health risks, while at the same time preserving the use of essential
chemistries and products that are important to the U.S. economy. The commenter encouraged
EPA to work with stakeholders to ensure consistent, proper, and successful implementation of
TSCA, specifically in these precedent-setting risk determination revisions.

EPA RESPONSE:

EPA thanks the commenters for their support of ongoing risk evaluation and risk management of
chemical substances under TSCA. EPA appreciates the commenter's recommendations for future
risk evaluations and the forthcoming risk management rules and encourages the commenter to
submit chemical-specific comments during future risk evaluation and rulemaking comment
periods, including on the issues the commenters have raised, such as data gaps consideration of
PESS, and sources of exposure. The revised unreasonable risk determination for PCE is based on
the peer reviewed risk characterization in the December 2020 Risk Evaluation, based on
reasonably available information pursuant to TSCA section 26(k) and 40 CFR 702.33, and
developed in accordance with TSCA section 26(h) and (i) to make decisions under TSCA section
6 in a manner consistent with the best available science and based on the weight of scientific
evidence. The December 2020 Risk Evaluation included conditions of use in which PCE was
intended, known or reasonably foreseen to be manufactured, processed, distributed in commerce,
used, or disposed of, including disposal-related hazards and exposures to workers and ONUs at
disposal facilities The policy changes described in the Federal Register Notice announcing the
availability of the draft revised risk determination for PCE do not amend or impact the
underlying data and analysis presented in the risk characterization of the December 2020 PCE
Risk Evaluation.

EPA also acknowledges the best practices established by states and industry experts. During
development of the TSCA section 6(a) risk management rulemaking for PCE EPA has engaged
in required consultations such as the federalism consultation as specified in Executive Order

45


-------
Perchloroethylene (PCE); Revision to Toxic Substances Control Act (TSCA) Risk Determination

Response to Public Comments Received

13132 (64 FR 43255, August 10, 1999) and the tribal consultation as specified in Executive
Order 13175 (65 FR 67249, November 9, 2000), to solicit feedback from the perspective of state
and local governments. In addition to the formal consultations, EPA has met directly with state
and local regulators to hear concerns and gain insight on existing regulations, research, and best
practices. Additionally, EPA has engaged in discussions with representatives from different
industries, non-governmental organizations, technical experts, and users of PCE, and welcomes
continued engagement throughout the development of a risk management rulemaking.

With respect to impacts from this revised unreasonable risk determination on risk management
of PCE, EPA will propose a regulatory action with requirements under TSCA section 6(a) to the
extent necessary so that PCE no longer presents unreasonable risk of injury to health, including
unreasonable risk to identified PESS.

Section 12 - Comments on potential revisions to other risk determinations for the first ten
chemicals

An advocacy organization stated (0132) that the Agency must make holistic risk determinations
for all of the initial 10 risk evaluations and apply the whole chemical approach to all risk
evaluations moving forward. In other words, as they describe, EPA should only consider a whole
chemical approach because it accurately profiles the unreasonable risk a chemical may pose to
human health and the environment. An industry trade organization (0136) commented that as
EPA enacts rulemakings for other chemicals in the future, it should revert to evaluating these
substances on an individual COU basis to ensure innovation and production in the chemical
industry and broader economy are not restricted at the state level. The commenter stated its view
that EPA should avoid an approach that could result in the undesired and unintended outcome of
imposing high costs and strain on industry without the intended decrease in risk.

EPA RESPONSE:

EPA appreciates the comments. As EPA explained in the Federal Register Notice announcing the
availability of the draft revised risk determination for PCE, EPA plans to consider the
appropriate approach (e.g., whether to apply the whole chemical approach) for each chemical
substance risk evaluation on a case-by-case basis, taking into account considerations relevant to
the specific chemical substance in light of the Agency's obligations under TSCA. EPA
emphasizes that throughout the risk evaluation process, EPA must "determine whether a
chemical substance presents an unreasonable risk of injury to health or the environment, without
consideration of costs or other nonrisk factors" (TSCA section 6(b)(4)(A)), which would include
considerations for innovation and the national economy. However, during the TSCA section 6(a)
risk management rulemaking for any chemical found to present unreasonable risk, EPA does, as
part of the requirements under TSCA section 6(c), consider the reasonably ascertainable
economic consequences of the rule, including consideration of the effect of the rule on the
national economy, small business, technological innovation, the environment, and public health.

46


-------