EPA Proposes Revisions to TSCA Risk Evaluation Framework for Existing Chemicals

On Tuesday, September 23, 2025, the U.S. Environmental Protection Agency (EPA) published a proposed rule to revise its procedural framework for conducting risk evaluations for chemicals already in commerce under the Toxic Substances Control Act (TSCA) (Proposed Framework Rule). The purpose of risk evaluation is to determine whether an existing chemical substance presents an unreasonable risk to health or the environment, under the conditions of use. Risk evaluation is the second step in EPA’s existing chemical process under TSCA, before EPA develops and proposes a rule to manage any such unreasonable risks.

The proposed amendments largely rescind or revise amendments to EPA’s risk evaluation process adopted in May 2024, that EPA now considers inconsistent with the statute or overly burdensome. Most notably, the Biden EPA had adopted a “whole chemical” approach to risk evaluations by requiring a single overall risk determination across all uses, rather than separate assessments for each use. It also factored in exposure pathways regulated under other environmental statutes (e.g., the Clean Air Act’s National Emissions Standards for Hazardous Air Pollutants) and directed staff to assume workers lack adequate protective equipment despite regulatory requirements for such equipment by the Occupational Safety Health Administration.

EPA originally announced its intent to reconsider the framework on March 10, 2025, citing the role of chemicals in the country’s economy, the need for timely completion of risk evaluations, and President Trump’s deregulatory executive order.[1] In its press release on the Proposed Framework Rule, EPA stated these amendments would align with Administrator Zeldin’s “Powering the Great American Comeback” initiative by “ensuring chemicals that are already in the marketplace are reviewed in a way that adheres to Congress’s intent for the law, uses the best available science and provides certainty for the regulated community.”

Key proposed amendments include:

• Separate Risk Determinations: Require EPA to make a separate determination of unreasonable risk for each of the conditions of use within the scope of the chemical’s risk evaluation, instead of a single risk determination on the chemical substance as a whole.
• Scope of Evaluations: Restore EPA’s discretionary authority to determine which conditions of use and exposure pathways the agency will consider in a risk evaluation, rather than requiring analysis of every conceivable use and pathway.
• Occupational Exposure: Allow consideration of occupational exposure controls, e.g., personal protective equipment and industrial controls, when assessing occupational exposure and making risk determinations.
• Definitions: Revise certain regulatory definitions, e.g., EPA would remove the reference to “overburdened communities” in the definition of “potentially exposed or susceptible subpopulations” and add a definition for “weight of scientific evidence” from President Trump’s “Gold Standard Science” executive order.[2]
• Process Flexibility: Allow EPA to revise or supplement risk evaluations without having to restart the prioritization process to ensure errors can be corrected and new information incorporated, while still meeting the statutory deadlines.

Among other topics, EPA is also specifically seeking comments on the scope and transparency of peer review requirements. EPA is accepting comments until November 7, 2025.

[1] EO 14219, Ensuring Lawful Governance and Implementing the President’s “Department of Government Efficiency” Deregulatory Initiative, 90 Fed. Reg. 10,583 (Feb. 19, 2025).

[2] EO 14303, Restoring Gold Standard Science, 90 Fed. Reg. 22,601 (May 23, 2025).

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