Chemical Substances Undergoing Prioritization
As required under section 6(b) of the Toxic Substances Control Act (TSCA), EPA must conduct a prioritization process to determine if chemical substances are a high- or low-priority for risk evaluation.
2023-2024 Prioritization Process
On July 26, 2024, EPA proposed to designate five chemicals as High-Priority Substances for risk evaluation under TSCA. If EPA finalizes these designations the Agency will begin risk evaluations for these chemicals.
In December 2023, EPA initiated the process of prioritizing five chemicals as candidates for high-priority designation and subsequent risk evaluation:
- 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).
All five chemicals were selected from the 2014 TSCA Work Plan, which is a list of chemicals identified by EPA for further assessment based on their hazards and potential for exposure.
In selecting these five chemicals, EPA considered numerous factors including how they are used, their known hazards and exposures, and the availability of information on each chemical to allow for fulsome risk evaluations to be completed. Between September and November 2023, EPA met with federal partners, industry, environmental organizations, labor organizations, state and local governments, and Tribes to discuss the prioritization process and presented a list of 15 chemical substances EPA was considering for prioritization. EPA took feedback from these discussions into consideration when selecting this set of five chemicals for prioritization.
Upon publication of the Federal Register Notice in December 2023, EPA received comments and requested further information on these factors, as well as any other information relevant to the potential risks of these chemicals to will inform the Agency’s review of these chemicals. In March 2024, EPA extended the comment period for MBOCA by an additional 30 days.
Comments on MBOCA can be submitted to docket ID number EPA-HQ-OPPT-2018-0464 on www.regulations.gov until April 17, 2024. Comments on the other four chemicals were submitted until March 18, 2024. EPA received public comments on topics such as manufacturing, processing, and consumer/commercial uses and products; release and exposure information; and potential hazards of these chemical substances, as well as previously conducted hazard assessments. For more information, please see the Federal Register Notice at EPA-HQ-OPPT-2023-0601.
During this second 90-day public comment period, EPA is particularly interested in relevant information for any of the prioritization considerations, such as chemicals’ uses conditions of use and encourages the public to submit comment. EPA will accept public comments on the proposed designations for 90 days after publication via docket EPA-HQ-OPPT-2023-0601 at the Regulations.gov page. Comments that are not chemical-specific may be submitted to docket ID number EPA-HQ-OPPT-2023-0601. Information and comments that are specific to a respective chemical should be submitted to chemical-specific dockets listed below.
Read the Federal Register Notice
Prioritization Status
This table provides a list of the chemicals undergoing the process for prioritization for risk evaluation under TSCA. See the Prioritization of Existing Chemicals for Risk Evaluation under TSCA page for an overview of the prioritization process. Thus far, Chemical substances being prioritized for risk evaluation were selected from the 2014 TSCA Work Plan, which is a list of chemicals identified by EPA for further assessment based on their hazards and potential for exposure.
|
Chemical Name |
CASRN number |
Date Initiated |
Docket ID Number |
Prioritization Status |
Priority Designation |
|
Acetaldehyde |
75-07-0 |
12/2023 |
Proposed as High-Priority Substance |
Pending final designation |
|
|
Acrylonitrile |
107-13-1 |
12/2023 |
Proposed as High-Priority Substance |
Pending final designation |
|
|
Benzenamine |
62-53-3 |
12/2023 |
Proposed as High-Priority Substance |
Pending final designation |
|
|
Vinyl Chloride |
75-01-4 |
12/2023 |
Proposed as High-Priority Substance |
Pending final designation |
|
|
4,4’ Methylene bis(2-chloraniline) (MBOCA) |
101-14-4 |
12/2023 |
Proposed as High-Priority Substance |
Pending final designation |
Previous Prioritization Status Under TSCA
On March 20, 2019, EPA initiated the prioritization process by issuing a list of 40 chemical substances and began the effort to designate 20 High-Priority Substances for subsequent risk evaluation and to designate 20 Low-Priority Substances, meaning that risk evaluation is not warranted at this time. On December 20, 2019, EPA finalized the designation of the 20 high-priority chemicals. On February 20, 2020, EPA finalized the designation of the 20 low-priority chemicals.