US Environmental Protection Agency Proposes Amendments to Chemical Risk Assessment Process

The United States Environmental Protection Agency (EPA) has announced a series of proposed amendments to the risk assessment process for existing chemicals, operating within the framework of the Toxic Substances Control Act (TSCA). The stated objective of these changes is to improve the efficiency of chemical reviews conducted under TSCA.

Key Provisions of the Proposed Amendments

The proposed amendments outline several significant modifications:

1. The EPA will now be required to make individual risk determinations for each specific condition of use within a chemical's assessment scope. This shifts from a previous approach of issuing a single, overarching risk determination for a chemical substance as a whole, aligning with mandates under the Frank Lautenberg 21st Century Chemical Safety Act.

2. The proposals clarify how the EPA will factor in existing occupational exposure controls during its risk evaluations. This includes the consideration of measures such as personal protective equipment and engineering controls when making final risk determinations.

3. The amendments seek to define the EPA's discretionary power in selecting which conditions of use and exposure pathways must be included in a risk assessment.

4. Certain regulatory definitions will be revised to ensure consistency with Executive Order 14303, 'Restoring Gold Standard Science', which was signed on 23 May 2025. This change is intended to bolster transparency and accountability throughout the risk assessment procedure.

5. The procedures and requirements for the EPA to revise or supplement its risk assessment documents will be refined. This is designed to compel the agency to complete both risk assessments and subsequent risk management actions within legally mandated timeframes.

6. Adjustments will be made to the procedures and information collection obligations for manufacturers, including importers, when they submit requests for the EPA to conduct TSCA risk assessments.

Regulatory Background

The context for these amendments stems from the Frank Lautenberg 21st Century Chemical Safety Act, which was signed into law on 22 June 2016. This act substantially amended the original TSCA by:

• Establishing a process for identifying high-priority and low-priority chemicals.

• Mandating that the EPA conduct risk evaluations for existing chemicals within specified timeframes, focusing first on high-priority substances.

• Requiring that new chemicals be deemed safe before they can enter the US market.

• Stipulating that risk assessments must exclude cost and other non-risk factors.

• Mandating the publication of proposed and final rules within set periods after a chemical is determined to pose an unreasonable risk.

Furthermore, the Executive Order 14303, 'Restoring Gold Standard Science', signed by President Trump on 23 May 2025, requires all levels of research institutions to align their activities with established scientific gold standards, including principles of transparency, reproducibility, falsifiability, and the absence of conflicts of interest.