Proposed High-Priority Substance Designations Under the Toxic Substances Control Act (TSCA); Notice of Availability

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Notice.

SUMMARY:

Under the Toxic Substances Control Act (TSCA) and related implementing regulations, the Environmental Protection Agency (EPA or Agency) is proposing to designate acetaldehyde (CASRN 75-07-0), acrylonitrile (CASRN 107-13-1), benzenamine (CASRN 62-53-3), vinyl chloride (CASRN 75-01-4), and 4,4-methylene bis(2-chloroaniline) (MBOCA) (CASRN 101-14-4) as High-Priority Substances for risk evaluation. EPA is providing a 90-day comment period, during which interested persons may submit comments on the proposed designations of these chemicals as High-Priority Substances for risk evaluation.

DATES:

Comments must be received on or before October 23, 2024.

ADDRESSES:

Submit your comments, identified by docket identification (ID) number, through https://www.regulations.gov. Follow the online instructions for submitting comments. For comments not related to a specific chemical, including general comments on Unit IV.A., use docket ID number EPA-HQ-OPPT-2023-0601; submit information on the candidates for which EPA is initiating the prioritization process to the applicable chemical-specific docket ID number identified in Unit V. Do not submit electronically any information you consider to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Additional instructions on commenting or visiting the docket, along with more information about dockets generally, is available at 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: au.sarah@epa.gov.

For general information: The TSCA-Hotline, ABVI-Goodwill, 422 South Clinton Ave., Rochester, NY 14620; telephone number: (202) 554-1404; email address: TSCA-Hotline@epa.gov.

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, users, non-profit organizations in the environmental and public health sectors, state and local government agencies, and members of the public. Since other entities may also be interested, the Agency 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 proposing to designate five chemical substances as High-Priority Substances for risk evaluation pursuant to TSCA section 6(b), 15 U.S.C. 2605(b): acetaldehyde (CASRN 75-07-0), acrylonitrile (CASRN 107-13-1), benzenamine (CASRN 62-53-3), vinyl chloride (CASRN 75-01-4), and 4,4'-methylene bis(2-chloroaniline) (MBOCA) (CASRN 101-14-4). This document includes a summary of the approach EPA used to support the proposed designation for each chemical substance and instructions on how to access the chemical-specific information, analysis, and basis EPA used to make the proposed designation for each chemical substance.

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 the prioritization process for chemical substances that may be designated as High-Priority Substances for risk evaluation. Because EPA generally expects to complete five risk evaluations per year over the next several years, EPA is proposing the designation of five chemical substances as High-Priority Substances under TSCA section 6(b)(3)(C), which requires EPA to designate at least one chemical substance as a High-Priority Substance upon completion of each risk evaluation of a High-Priority Substance. By proposing the designation of these five chemical substances as High-Priority Substances, EPA continues to build a sustainable pipeline of existing chemical risk evaluations under TSCA section 6(b). The request for interested persons to submit comments on EPA's proposed designation of chemical substances as High-Priority Substances is required by TSCA section 6(b)(1)(C)(ii) and implementing regulations (40 CFR 702.9(g)).

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

This document is issued pursuant to authorities in TSCA section 6(b)(1) and TSCA section 6(b)(3)(C), and the EPA implementing regulations in 40 CFR part 702.

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

This document identifies five chemical substances for proposed designation as High-Priority Substances for risk evaluation and provides a 90-day comment period for interested persons to submit comments on the proposed designations. This document does not establish requirements on persons or entities outside of the Agency. No incremental impacts are therefore anticipated, and consequently EPA did not estimate potential incremental impacts for this action.

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

1. Submitting CBI.

Do not submit CBI to EPA through https://www.regulations.gov or email. If you wish to include CBI in your comment, please follow the applicable instructions at https://www.epa.gov/dockets/commenting-epa-dockets#rules and clearly mark the part or all of the information that you claim to be CBI. In addition to one complete version of the comment that includes information claimed as CBI, a copy of the comment that does not contain the information claimed as CBI must be submitted for inclusion in the public docket. Information so marked will not be disclosed except in accordance with procedures set forth in 40 CFR part 2 and/or 40 CFR part 703, as applicable.

2. Tips for preparing your comments.

When preparing and submitting your comments, see the commenting tips at https://www.epa.gov/dockets/commenting-epa-dockets.

II. Background

As required by TSCA section 6(b) and as described in 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. Under TSCA section 6(b)(1)(B) and its implementing regulations (40 CFR 702.3), a High-Priority Substance is defined as a chemical substance that EPA determines, 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 potentially exposed or susceptible subpopulations identified as relevant by EPA.

A proposed designation of a chemical substance as a High-Priority Substance is not a finding of unreasonable risk. Rather, when prioritization is complete, for those chemical substances designated as High-Priority Substances, the Agency will have evidence that each such substance 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. Final designation of a chemical substance as a High-Priority Substance initiates the TSCA risk evaluation process (40 CFR 702.17), which culminates in a finding of whether the chemical substance presents an unreasonable risk under its conditions of use.

This document is intended to fulfill the TSCA section 6(b)(1)(C)(ii) requirement that EPA propose the designation of a chemical substance as a High-Priority Substance for risk evaluation after conducting a screening review as required by TSCA section 6(b)(1)(A) (see also 40 CFR 702.9(a)). This document is also intended to fulfill the requirement in TSCA section 6(b)(1)(C)(ii) that EPA request public comments on proposed priority designations (see 40 CFR 702.9(g)).

EPA generally used reasonably available information to screen each of the five candidate chemical substances against the following criteria and considerations (see also 40 CFR 702.9(a)):

• 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.

As described in 40 CFR 702.9(b), in conducting the screening review during the prioritization process, EPA considered sources of information relevant to the screening 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) (Ref. 2). In addition, as required by 40 CFR 702.9, EPA considered the hazard and exposure potential of the chemical substances and did not consider costs or other non-risk factors in making a proposed priority designation.

III. Information and Comments Received

The initiation of the prioritization process (Ref. 1) included a 90-day public comment period during which interested persons were able to submit relevant information on the five chemical substances identified as candidates for High-Priority Substance designation. EPA received over 9,000 submissions from commenters, including private citizens, potentially affected businesses, trade associations, Tribes, environmental and public health advocacy groups, and academia. Comments addressed the overall prioritization process ( e.g., the collection and consideration of relevant information); the review process ( e.g., the use of data and approaches in risk evaluation); information specific to the candidate chemical substances ( e.g., relevant studies, assessments, and conditions of use); and topics not germane to this prioritization process ( e.g., scheduling future chemicals for prioritization and concerns about risk evaluation fees). To the extent that comments provided information on additional conditions of use for these candidate High-Priority Substances, those conditions of use are discussed in the proposed designation documents for each chemical substance. EPA will respond to those and any additional comments on the proposed designations when EPA issues the final priority designation of these chemical substances.

IV. Screening Review Criteria and Chemical Substances for Which EPA Is Proposing a High-Priority Designation

A. What information, analysis, and basis were used to support the proposed High-Priority Substance designations?

EPA used reasonably available information, including public comments received during the 90-day comment period following initiation of the prioritization process (Ref. 1), to analyze the candidate chemical substances against the criteria and considerations in TSCA section 6(b)(1)(A) and 40 CFR 702.9 (see Unit IV.). EPA developed a proposed designation document for each chemical substance that identifies the information, analysis, and basis used to support the proposed designation of each as a High-Priority Substance for risk evaluation. Additionally, EPA developed a systematic review support document titled “Updated Search Strategies Used to Identify Potentially Relevant Discipline-Specific Information” (Ref. 3) to further explain how potentially relevant data sources for various disciplines ( e.g., physical and chemical properties, occupational exposure and environmental release, environmental and human health hazard), are identified from the larger set of data sources identified for each of the chemical substances currently being proposed as High-Priority Substances for risk evaluation. These documents are available in the docket for each chemical substance proposed for designation as a High-Priority Substance for risk evaluation.

Also included in each document is an explanation of the approach EPA used to conduct the review. Each document includes an overview of the requirements in TSCA section 6(b)(1)(A) and the regulatory section addressing the following review criteria and considerations (40 CFR 702.9):

1. Production volume or significant changes in production volume.

EPA considered the reasonably available information on the current production volume or significant changes in production volume of the chemical substance. EPA primarily used reported information from manufacturers (including importers) under EPA's Chemical Data Reporting (CDR) rule (40 CFR part 711). EPA assembled information reported to the Agency from 1986 through 2020 on the production volume under the Inventory Update Rule (IUR) and CDR. The most recent principal reporting year for which CDR data are available is 2019, for which information was reported in 2020.

2. Conditions of use or significant changes in conditions of use.

EPA considered the reasonably available information on conditions of use or significant changes in conditions of use of the chemical substances. TSCA section 3(4) defines the term “conditions of use” to mean the circumstances, as determined by the Administrator, under which a chemical substance is intended, known, or reasonably foreseen to be manufactured, processed, distributed in commerce, used, or disposed of. EPA assembled information submitted by manufacturers (including importers) during the 2016 and 2020 CDR reporting cycles. CDR requires manufacturers (including importers) to report information on the chemical substances they produce domestically or import into the United States. The threshold for such reporting is generally production volume of more than 25,000 lbs per site. Based on the manufacturing information, industrial processing and use information, consumer and commercial use information reported under CDR during the 2016 and 2020 reporting cycles, EPA developed a list of conditions of use. In addition, EPA reviewed uses from other publicly available data sources such as the Toxics Release Inventory (TRI), Discharge Monitoring Reports (DMRs), National Emissions Inventory (NEI), Safety Data Sheets (SDS), Chemical Exposure Knowledgebase (ChemExpo), High Priority Chemicals Data System (HPCDS), chemical-specific information received from public commenters, and chemical-specific information from EPA's screening review of the reasonably available information for each chemical substance. Should EPA make a final decision to designate a chemical substance as a High-Priority Substance for risk evaluation, further characterization of relevant TSCA conditions of use will be identified during the risk evaluation process as part of the Agency's scope document.

3. Potentially exposed or susceptible subpopulations.

In this review, EPA considered reasonably available information to identify potentially exposed or susceptible subpopulations. At this stage, EPA analyzed information about children, women of reproductive age, consumers, workers, and overburdened communities for the following scenarios:

• For children, EPA screened for each chemical substance's use in products and articles regulated under TSCA and intended for children, using CDR information reported during the 2016 and 2020 CDR cycles. EPA presented information regarding those commercial and consumer uses when the chemical substance was identified as being used in products intended for children and also indicated if use in children's products was identified in the High Priority Chemicals Data System (HPCDS). Additionally, EPA identified the potential for developmental hazards resulting from exposure to the chemical substance that may affect children.
• For women of reproductive age, EPA screened against the exposure and hazard information for the chemical substance that characterized potential for reproductive and/or developmental effects following exposure to the chemical substance.
• For consumers, EPA characterized the potential for consumer exposure based on consumer uses reported to CDR during the 2016 and 2020 reporting cycles, and reported consumer uses in the Chemical and Products database (CPDat), HPCDS, and public comment.
• For workers, EPA characterized the potential for occupational exposures to workers based on the conditions of use of each chemical.
• For overburdened communities, EPA described the considerations for overburdened communities that may experience disproportionate environmental harms, risks, or multiple burdens from chemical exposure.

4. Persistence and bioaccumulation.

EPA considered reasonably available information of the chemical substance and assessed physical and chemical properties used to determine persistence and bioaccumulation based on the best available science. In the proposed designation documents, EPA presents a summary of the physical, chemical, environmental fate, and transport properties of each chemical substance.

5. Storage near significant sources of drinking water.

TSCA section 6(b)(1)(A) specifically requires the Agency to consider the chemical substance's storage near significant sources of drinking water. EPA reviewed reasonably available information, including certain existing regulations or protections in place for the proposed chemical substances, such as existing National Primary Drinking Water Regulations (40 CFR part 141) and other regulations under the Clean Water Act (CWA) (40 CFR 401.15). In addition, EPA considered the consolidated list of chemicals subject to reporting requirements under the Emergency Planning and Community Right-to-Know Act (EPCRA) section 302 and section 313, Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), and the Clean Air Act (CAA) (section 112) (Regulated Chemicals for Accidental Release Prevention). Regulation under one or more of these authorities is an indication that a substance is a potential health or environmental hazard, which, if released near a significant source of drinking water, may present unreasonable risk to health or the environment. To identify storage of chemical substances near significant sources of drinking water, EPA also identified facilities reporting the chemical substances to the TRI in 2022 near potential sources of drinking water using public water systems data stored in EPA's Safe Drinking Water Information System Federal Data Warehouse. EPA determined whether TRI reporting facilities are located inside defined Source Water Protection Areas or within 4 miles of wellheads to identify potential storage of each chemical substance near sources of surface water and groundwater, respectively.

6. Hazard potential.

EPA considered reasonably available information to identify the potential hazards for each chemical substance. EPA surveyed information from previous assessments and databases and summarized the reasonably available information for potential human health and environmental hazards by endpoints of concern.

7. Exposure potential.

EPA considered reasonably available information to identify potential environmental, worker/occupational, consumer, and general population exposure for each chemical substances for the following scenarios:

• For environmental exposure, EPA considered the conditions of use and activities associated with those conditions of use and considered environmental monitoring data and fate properties of each chemical substance to anticipate its presence in different environmental media.
• For worker/occupational exposure, EPA identified the conditions of use likely to result in workers being exposed to the chemical substance, such as manufacturing, processing, industrial and commercial use, distribution in commerce, and disposal.
• For consumer exposure, EPA considered consumer uses using CDR information and information from CPDat. Additionally, EPA considered the potential use in children's products from the High Priority Chemicals Data System (HPCDS) and through public comments.
• For general population exposure, EPA considered releases from certain conditions of use as reported in TRI, such as manufacturing, that may result in general population exposure via pathways and routes such as drinking water ingestion and/or inhalation from releases to the atmosphere.

8. Other risk-based criteria EPA determined to be relevant to the designation of the chemical substance.

EPA did not identify other risk-based criteria relevant to the proposed designations of the candidate chemical substances as High-Priority Substances for risk evaluation.

EPA is including in the docket a technical support document titled “Updated Search Strategies Used to Identify Potentially Relevant Discipline-Specific Information” (Ref 3.), which provides information describing the Agency's search methods for publicly available peer-reviewed and gray literature. The document also provides information describing the processes and tools used to identify discipline-specific pools of information from EPA's search for publicly available peer-reviewed and gray literature.

B. What are the chemicals being proposed as High-Priority Substances for risk evaluation?

EPA is proposing to designate acetaldehyde (CASRN 75-07-0), acrylonitrile (CASRN 107-13-1), benzenamine (CASRN 62-53-3), vinyl chloride (CASRN 75-01-4), and 4,4'-methylene bis(2-chloroaniline) (MBOCA) (CASRN 101-14-4) as High-Priority Substances for risk evaluation. The proposed designations are based on the preliminary conclusion that each such chemical substance satisfies the definition of High-Priority Substance in TSCA section 6(b)(1)(B) and 40 CFR 702.3. As mentioned previously, a proposed designation of a chemical substance as a High-Priority Substance is not a finding of unreasonable risk. Rather, when prioritization is complete, a final designation as a High-Priority Substance will initiate the risk evaluation for the chemical substance, which will culminate in a finding of whether the chemical substance presents an unreasonable risk to health or the environment under the conditions of use. Based on the information provided in the proposed designation documents, the Agency is proposing these five chemical substances as High-Priority Substances for risk evaluation. In each chemical substance's docket, EPA has included the chemical-specific designation document containing the information, analysis, and basis used to support the proposed designation.

V. Request for Comment

EPA is interested in comments that would inform the exposure and hazard assessments and the identification of conditions of use for the following chemicals:

• 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.

VI. References

The following is a list of the documents specifically referenced in this document. The docket includes these documents and other information considered by EPA, including documents referenced within the documents included in the docket, even if the referenced documents are not physically located in the docket. For assistance in locating these other documents, please consult the person listed under FOR FURTHER INFORMATION CONTACT .

1. EPA. Initiation of Prioritization Under the Toxic Substances Control Act (TSCA). Notice (88 FR 87423, December 18, 2023 (FRL 11581-01-OCSPP)).

2. EPA. TSCA Work Plan Chemicals; Methods Document. February 2012.

3. EPA. Updated Search Strategies Used to Identify Potentially Relevant Discipline-Specific Information. 2024.

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