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[Federal Register Volume 89, Number 243 (Wednesday, December 18, 2024)]
[Notices]
[Pages 102900-102903]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-29830]

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ENVIRONMENTAL PROTECTION AGENCY

[EPA-HQ-OPPT-2023-0601; FRL-11581-07-OCSPP]

High-Priority Substance Designations Under the Toxic Substances 
Control Act (TSCA) and Initiation of Risk Evaluation on High-Priority 
Substances; Notice of Availability

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice.

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SUMMARY: Under the Toxic Substances Control Act (TSCA) and related 
implementing regulations, EPA is designating five chemicals as High-
Priority Substances for risk evaluation. This document provides the 
identity of five chemical substances for final designation as High-
Priority Substances for risk evaluation, EPA's rationale for final 
designation as High-Priority Substances, and instructions on how to 
access the chemical-specific information, analysis, and basis EPA used 
to support final designations for the chemical substances. A 
designation of a substance as a High-Priority Substance is not a 
finding of unreasonable risk. Rather, the designation of these chemical 
substances as high priority constitutes the initiation of evaluation of 
associated risk.

DATES: The designations of High-Priority Substances for risk evaluation 
in this notice are effective December 18, 2024.

ADDRESSES: The docket for this action, identified by docket 
identification (ID) number EPA-HQ-OPPT-2023-0601, is available online 
at https://www.regulations.gov. In addition, the docket ID numbers for 
the individual chemical substances designated in Unit IV. are as 
follows: Acetaldehyde (EPA-HQ-OPPT-2018-0497); Acrylonitrile (EPA-HQ-
OPPT-2018-0449); Benzenamine (EPA-HQ-OPPT-2018-0474); Vinyl Chloride 
(EPA-HQ-OPPT-2018-0448); and 4,4'-Methylene bis (2- chloroaniline) 
(MBOCA) (EPA-HQ-OPPT-2018-0464). Additional information about dockets 
generally, along with instructions for visiting the docket in-person, 
is available at https://www.epa.gov/dockets.

FOR FURTHER INFORMATION CONTACT: 
    For technical information: Sarah Au, Data Gathering, Management and 
Policy Division (7406M), Office of Pollution Prevention and Toxics, 
Environmental Protection Agency, 1200 Pennsylvania Ave. NW, Washington, 
DC 20460-0001; telephone number: (202) 564-0398; email address: 
[email protected].
    For general information: The TSCA-Hotline, ABVI-Goodwill, 422 South 
Clinton Ave., Rochester, NY 14620; telephone number: (202) 554-1404; 
email address: [email protected].

SUPPLEMENTARY INFORMATION: 

I. Executive Summary

A. Does this action apply to me?

    This action is directed to the public in general and may be of 
interest to entities that currently or may manufacture (including 
import) a chemical substance regulated under TSCA (e.g., entities 
identified under North American Industrial Classification System 
(NAICS) codes 325 and 324110). The action may also be of interest to 
chemical processors, distributors in commerce, and users, non-
governmental organizations in the environmental and public health 
sectors, state and local government agencies, Tribes, and members of 
the public. Since other entities may also be interested, EPA has not 
attempted to describe all the specific entities and corresponding NAICS 
codes for entities that may be interested in or affected by this 
action.

B. What action is the Agency taking?

    EPA is finalizing the designation of five chemical substances as 
High-Priority Substances for risk evaluation pursuant to section 6(b) 
of TSCA, 15 U.S.C. 2605(b). This document includes a high-level summary 
of comments received during the two 90-day comment periods during which 
the public submitted comments on EPA's initiation of prioritization 
(Ref. 1) and the proposed designations of those five chemicals as High-
Priority Substances for risk evaluation (Ref. 2), as well as a high-
level summary of Agency responses to those comments received during 
both 90-day public comment periods. The comments and EPA's responses 
are discussed in more depth in the response to comments document (Ref. 
3). EPA also considered comments received during and following the 
prioritization public webinar that occurred in February 2024, during 
which EPA explained the prioritization process and provided an overview 
of information that may be used to inform the considerations that 
ultimately support a High- or Low-Priority Substance designation, such 
as information on conditions of use and health effects resulting from 
exposure to the chemicals of interest.

C. Why is the Agency taking this action?

    TSCA section 6(b) and implementing regulations at 40 CFR part 702, 
subpart A require EPA to carry out a prioritization process for 
chemical substances that may be designated as high priority for risk 
evaluation. EPA generally expects to complete five risk evaluations per 
year over the next several years, and TSCA section 6(b)(3)(C) requires 
EPA to designate at least one High-Priority Substance upon completion 
of each risk evaluation for a High-Priority Substance. Pursuant to TSCA 
section 6(b)(2)(B), EPA is finalizing the designation of the five 
chemical substances as High-Priority Substances for risk evaluation 
identified as candidates for High-Priority Substance designation when 
EPA initiated the prioritization process on December 18, 2023 (Ref. 1). 
As required under TSCA section 6(b)(3)(C), EPA is specifying the 
designation of: MBOCA to replace the final risk evaluation for 1,1-
dichloroethane; acetaldehyde to replace the final risk evaluation for 
1,3-butadiene; acrylonitrile to replace the final risk evaluation for 
dicyclohexyl phthalate; benzenamine to replace the final risk 
evaluation for formaldehyde; and vinyl chloride to replace the final 
risk evaluation for tris(2-chloroethyl) phosphate.

D. What is the Agency's authority for taking this action?

    This document is issued pursuant to TSCA section 6(b)(1) and 
6(b)(3)(C).

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

    This document identifies the five chemical substances for which EPA 
is initiating the risk evaluation process and the five chemical 
substances that have already or will have risk evaluations completed 
which they will replace. This document does not establish any 
requirements on persons or entities outside of the Agency. No 
incremental impacts are therefore anticipated, and consequently EPA did

[[Page 102901]]

not estimate potential incremental impacts for this action.

II. Background

    TSCA section 6(b)(1) requires EPA to prioritize chemical substances 
for risk evaluation. In accordance with TSCA section 6(b) and 40 CFR 
702.7, on December 18, 2023 (Ref. 1) EPA initiated the prioritization 
process for five chemical substances identified as candidates for High-
Priority Substance designation. On July 25, 2024, EPA proposed to 
designate the same five chemical substances as High-Priority Substances 
for risk evaluation (Ref. 2). That notice included a summary of the 
approach used by EPA to support the proposed designations, links to the 
proposed designation document for each of the chemical substances, and 
instructions on how to access the chemical-specific information, 
analysis, and basis EPA used to make the proposed designation for each 
chemical substance.
    Under TSCA section 6(b)(1)(B) and implementing regulations (40 CFR 
702.3), a High-Priority Substance is defined as ``a chemical substance 
that EPA concludes, without consideration of costs or other non-risk 
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 EPA.''
    A designation of a substance as a High-Priority Substance is not a 
finding of unreasonable risk. Rather, when prioritization is complete, 
for those chemicals designated as High-Priority Substances, the Agency 
will have evidence on hazards and exposures that supports a finding 
that the substances may present an unreasonable risk of injury to 
health or the environment under the conditions of use. Final 
designation of a High-Priority Substance initiates the risk evaluation 
process (40 CFR 702.17), which culminates in a finding of whether the 
chemical substance presents an unreasonable risk of injury to health or 
the environment under the conditions of use.
    As described in the notice proposing to designate the five chemical 
substances as High-Priority Substances for risk evaluation (Ref. 2), 
``EPA will generally use reasonably available information to screen the 
candidate chemical substance[s] against the following criteria and 
considerations:
     The chemical substance's hazard and exposure potential;
     The chemical substance's persistence and bioaccumulation;
     Potentially exposed or susceptible subpopulations;
     Storage of the chemical substance near significant sources 
of drinking water;
     The chemical substance's conditions of use or significant 
changes in conditions of use;
     The chemical substance's production volume or significant 
changes in production volume; and
     Other risk-based criteria that EPA determines to be 
relevant to the designation of the chemical substance's priority'' (40 
CFR 702.9(a)).
    When selecting candidates for prioritization, the Agency also 
generally intends to consider (1) Agency priorities (with consideration 
of the priorities of other Federal agencies), (2) Quantity and quality 
of information (to ensure that information necessary to prioritize the 
substance is reasonably available), and (3) Overall workload (the 
Agency will be mindful of the complexity associated with the assessment 
of the chemical substance to ensure timely completion of prioritization 
and risk evaluation of each substance) (Ref. 5).
    A more detailed discussion of the information, analysis, and basis 
used to support the proposed High-Priority Substance designation can be 
found in Unit IV.A of the July 25, 2024, notice (Ref. 2).
    As described in 40 CFR 702.9(b), in conducting the screening review 
during the prioritization process, EPA considered sources of reasonably 
available information relevant to the review criteria as outlined in 
the statute (TSCA section 6(b)(1)(A)) and implementing regulations (40 
CFR 702.9(a)) and consistent with the scientific standards of TSCA 
section 26(h), including, as appropriate, sources for hazard and 
exposure data listed in Appendices A and B of the ``TSCA Work Plan 
Chemicals: Methods Document'' (February 2012), and did not consider 
costs or other non-risk factors in making a proposed High-Priority 
Substance designation (see TSCA Section 6(b) and 40 CFR 702.9).
    After considering additional information collected from the 
proposed designation process, described in Unit III., EPA is finalizing 
the High-Priority Substance designations of the same five chemical 
substances proposed for High-Priority Substance designations, 
consistent with the scientific standards of TSCA section 26(h) and (i). 
EPA did not consider costs or other non-risk factors in making the 
final priority designations. Instructions on how to access the 
chemical-specific information, analysis, and basis used by EPA to 
support the final designation for each chemical substance can be found 
in Unit IV. A general statement of the condition(s) of use that were 
the primary basis for each designation is contained in Unit IV. 
Pursuant to TSCA section 6(b)(3)(A) and 40 CFR 702.17, the designation 
of these chemical substances as High-Priority Substances constitutes 
the initiation of the risk evaluations on the substances.

III. Information and Comments Received

A. Overview of Public Comments

    EPA provided a 90-day comment period for the public to submit 
comments on the list of candidate High-Priority Substances immediately 
following the initiation of prioritization (Ref. 1) and provided a 
second 90-day comment period for the public to submit comments on the 
documents supporting the proposed designations of High-Priority 
Substances for risk evaluation (Ref. 2). The two comment periods are 
required by TSCA section 6(b)(1)(C) and implementing regulations (40 
CFR 702.7(d) and 702.9(g)).
    Under TSCA section 6(b)(1)(C)(i), EPA must ``request interested 
persons to submit relevant information on a chemical substance that EPA 
has initiated the prioritization process on, before proposing a 
priority designation for the chemical substance, and provide 90 days 
for such information to be provided'' (Ref. 1). At initiation of the 
prioritization process, EPA published a Federal Register notice 
identifying five chemical substances and provided a general explanation 
for why the Agency chose to initiate prioritization on those chemical 
substances. During this comment period, the public was invited to 
submit relevant information on the chemical substances undergoing 
prioritization, including, but not limited to, any information that may 
inform the screening review conducted pursuant to 40 CFR 702.9(a). The 
information received was considered when developing the proposed 
designations for the High-Priority Substances. The required 90-day 
comment period was extended for an additional 30 days to receive 
chemical-specific comments and information for MBOCA (docket ID No. 
EPA-HQ-OPPT-2018-0464). The second 90-day comment period following the 
proposed High-Priority Substance designations of the same five chemical 
substances identified as candidates for High-Priority Substance 
designation. Under TSCA section 6(b)(1)(C)(ii), EPA must ``publish each 
proposed designation of a chemical

[[Page 102902]]

substance as a High- or Low-Priority Substance, along with an 
identification of the information, analysis, and basis used to make the 
proposed designations, and provide 90 days for public comment on each 
such proposed designation'' (Ref. 2). The Federal Register notice 
proposing the designations of these substances as High-Priority for 
risk evaluation identified how to access the chemical-specific 
information, analysis, and basis used to support the proposed 
designations and announced the availability of a proposed designation 
document for each of the chemical substances undergoing prioritization. 
Interested persons were invited to submit comments, including 
additional information relevant to the chemical substances that were 
proposed as high priority for risk evaluations.
    To the extent that comments from the first comment period provided 
information on additional conditions of use for the candidate High-
Priority Substances, those conditions of use were discussed in the 
proposed designation documents for each chemical substance. Other 
information received specific to High-Priority Substances (e.g., 
relevant studies and assessments) was considered when making the final 
priority designations and will be considered as reasonably available 
information in the subsequent risk evaluation for each High-Priority 
Substance.
    Following a public webinar on February 20, 2024, EPA also received 
comments on the prioritization process and data considered up until 
that date for the five chemical substances for which EPA initiated 
prioritization in December 2023. The comments received were considered 
when developing the proposed and final designations for the High-
Priority Substances.
    EPA created one general docket to receive comments regarding the 
prioritization process (docket ID No. EPA-HQ-OPPT-2023-0601) and 
additional dockets to receive chemical-specific information (as 
identified under ADDRESSES). During the first public comment period, 
EPA also opened the pre-prioritization docket (docket ID No. EPA-HQ-
OPPT-2023-0606) to welcome potentially relevant information and 
comments on the candidate chemical substances that were not selected 
for prioritization.
    EPA received 96,011 comment submissions to inform prioritization; 
several of these comments were mass mailing campaigns with identical 
submissions. There were also many comments that could not be posted 
publicly due to inappropriate language, copyright violations, and empty 
submissions. Upon review, EPA received 977 unique submissions across 
both public comment periods. Some commenters included comments for 
multiple chemical substances in one submission and submitted the same 
comment to multiple dockets while other commenters chose to submit 
different sets of comments to each chemical-specific docket. EPA 
received submissions from individuals, Tribes, potentially affected 
businesses or trade associations, environmental and public health 
advocacy groups, academia, and other organizations. Comments addressed 
the overall prioritization process (e.g., the collection and 
consideration of relevant information, basis for designation, etc.), 
the review process (e.g., the use of data and approaches for screening 
review), information specific to the candidate chemical substances 
(e.g., relevant studies, previous assessments, and conditions of use 
information), as well as topics beyond the scope of this prioritization 
action or not related to the prioritization process in general (e.g., 
scheduling future chemicals for prioritization, risk evaluation, and 
risk management). EPA also received a few comments which were not 
related to TSCA. All comments received are identified by their 
respective docket ID number and are available at https://www.regulations.gov.
    EPA responded to comments related to the High-Priority Substance 
designations in two general categories: (1) General comments, including 
overarching and cross-cutting policy and process comments, received for 
the candidate High-Priority Substance designations; and (2) Chemical-
specific comments received on each proposed High-Priority Substance 
designation (Ref. 3). A high-level summary of the comments received 
related to the prioritization process and Agency responses follows in 
this unit. The comments and the Agency's responses are discussed in 
more depth in the response to comments document (Ref. 3), a copy of 
which is included in docket ID No. EPA-HQ-OPPT-2023-0601.

B. Comments on Candidate High-Priority Designations

    EPA received 748 unique comments during the first public comment 
period between December 18, 2023, and March 18, 2024, and 229 unique 
comments during the second comment period from July 25, 2024, to 
October 23, 2024, resulting in a total of 977 unique comment 
submissions. An additional two comment submissions were received for 
MBOCA during the 30-day extension of the first public comment period 
for Docket ID number: EPA-HQ-OPPT-2018-0464.
    EPA received several mass-mailing campaigns, totaling over 13,000 
signatures. All mass-mailing campaigns expressed their support for the 
prioritization process and encouraged EPA to prioritize one or all of 
the chemicals. Specifically, many of the mass mailing campaigns 
encouraged EPA to designate vinyl chloride as a High-Priority Substance 
under TSCA. In addition to the mass-mailing campaigns and 17 commenters 
who attended the prioritization public webinars in February 2024, EPA 
received over 100 comments expressing support for EPA's prioritization 
actions.
    Commenters expressed their concern regarding human health hazards 
and exposure potential of all five of the High-Priority Substances and 
asked that EPA consider specific potential health outcomes and exposure 
scenarios. Several commenters urged EPA to identify relevant 
potentially exposed or susceptible subpopulations (PESS), including 
infants, children, pregnant women, workers, the elderly, and people 
living in proximity to sources of contamination, as well as consider 
environmental justice concerns in the prioritization process. In 
addition, several commenters, including some of the mass-mailing 
campaigns, urged the Agency to consider all potential exposures and 
risks, including those from accidents, spills, and leaks, specifically 
potential exposure resulting from transportation incidents such as 
derailments and collisions, which may pose significant risk to fence 
line communities.
    Over 600 commenters asked EPA to ban vinyl chloride and emphasized 
the availability of hazard and exposure data demonstrating harm posed 
by vinyl chloride releases. Many commenters also cited the February 3, 
2023, train derailment that resulted in the release of and potential 
exposure to vinyl chloride by residents in East Palestine, Ohio.
    Each data submission and potentially relevant data source was 
screened using systematic review approaches for applicability and 
considered for the final designation of these chemical substances as 
High-Priority Substances and will be considered as reasonably available 
information.
    The Agency appreciates all comments and information submitted by 
the public for this action. For additional information regarding 
specific topics and EPA's responses to these comments, please see the 
Agency's full response to comments received (Ref. 3).

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IV. Designation as High-Priority Substances for Risk Evaluation

    Based on the information provided in the proposed designation 
documents, as referenced in the document that appeared in the Federal 
Register of July 25, 2024 (Ref. 2), and public comments received, 
including information pertaining to individual chemical substances, EPA 
is designating the same five chemicals as High-Priority Substances for 
risk evaluation under TSCA. Pursuant to 40 CFR 702.11, which states: 
``For High-Priority Substances, EPA generally expects to indicate which 
condition(s) of use were the primary basis for such designations.'' For 
all five High-Priority Substances the conditions of use which formed 
the primary basis for the designation were included in the proposed 
designation documents. The final High-Priority Substance designations 
are as follows:
     Acetaldehyde, CASRN 75-07-0, Docket ID number: EPA-HQ-
OPPT-2018-0497;
     Acrylonitrile, CASRN 107-13-1, Docket ID number: EPA-HQ-
OPPT-2018-0449;
     Benzenamine, CASRN 62-53-3, Docket ID number: EPA-HQ-OPPT-
2018-0474;
     Vinyl chloride, CASRN 75-01-4, Docket ID number: EPA-HQ-
OPPT-2018-0448; and
     4,4'-Methylene bis(2-chloroaniline) (MBOCA), CASRN 101-14-
4, Docket ID number: EPA-HQ-OPPT-2018-0464.
    The final designations are based on the conclusion that each 
chemical substance satisfies the definition of High-Priority Substance 
in TSCA section 6(b)(1)(B) and 40 CFR 702.3. EPA developed a document 
for each substance to identify the information, analysis and basis used 
to support the proposed designations as a High-Priority Substance for 
risk evaluation. These documents are available in the docket of each of 
the chemical substances. Also included in each document is an 
explanation of the approach used by EPA to conduct the review. Each 
document includes an overview of the requirements in TSCA section 
6(b)(1)(A) and a regulatory section addressing the review criteria and 
considerations (40 CFR 702.9).
    These designated High-Priority Substances will fulfill the 
statutory requirement to designate at least one high-priority substance 
upon completion of each risk evaluation for a High-Priority Substance, 
under TSCA section 6(b)(3)(C). Pursuant to TSCA section 6(b)(3)(A) and 
40 CFR 702.17, the designation of these chemical substances as High-
Priority Substances constitutes the initiation of the risk evaluations 
on the substances.
    A designation of a chemical substance as a High-Priority Substance 
is not a finding of unreasonable risk; rather, a final designation as a 
High-Priority Substance initiates the risk evaluation for the chemical 
substance. This is a three-year process that will culminate in a 
finding of whether or not the chemical substance presents an 
unreasonable risk of injury to health or the environment under the 
conditions of use. The chemical-specific designation documents 
containing the information, analysis and basis used to support the 
proposed designations are located in the docket for each chemical 
substance. As previously discussed, to the extent that comments 
provided information on additional conditions of use for the candidate 
High-Priority Substances for risk evaluation, those conditions of use 
were noted in the proposed designation documents for each chemical 
substance and may be reflected in the draft scope of the risk 
evaluation for each chemical substance, which will include the 
conceptual model and analysis plan for carrying out the evaluation. As 
such, EPA will not amend the proposed designation documents. Instead, 
additional submitted potentially relevant information specific to High-
Priority Substances (e.g., relevant studies and assessments) will be 
considered in subsequent phases of risk evaluation, including draft 
scope documents and draft risk evaluation documents, both of which will 
be subject to public comment opportunities.

V. References

    The following is a listing of the documents that are specifically 
referenced in this document. The docket for this action includes these 
documents and other information considered by EPA, including documents 
that are referenced within the documents that are included in the 
docket. For assistance in locating these referenced documents, please 
consult the technical person listed under FOR FURTHER INFORMATION 
CONTACT.

1. EPA. Initiation of Prioritization Under the Toxic Substances 
Control Act (TSCA). Notice. Federal Register. 88 FR 87423, December 
18, 2023 (FRL-11581-01-OCSPP).
2. EPA. Proposed High-Priority Substance Designations Under the 
Toxic Substances Control Act (TSCA). Federal Register. 89 FR 60420, 
July 25, 2024 (FRL-11581-03-OCSPP).
3. EPA. EPA Response to Public Comments Received on the ``Initiation 
of Prioritization Under the Toxic Substances Control Act'' and 
``Proposed High-Priority Substance Designations Under the Toxic 
Substances Control Act.'' December 18, 2024.
4. EPA. ``A Working Approach for Identifying Potential Candidate 
Chemicals for Prioritization.'' (https://www.epa.gov/sites/production/files/201809/documents/preprioritization_white_paper_9272018.pdf). September 27, 2018.

    Authority: 15 U.S.C. 2601 et seq.

    Dated: December 12, 2024.
Michal Freedhoff,
Assistant Administrator, Office of Chemical Safety and Pollution 
Prevention.
[FR Doc. 2024-29830 Filed 12-17-24; 8:45 am]
BILLING CODE 6560-50-P
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