Conducting Chemical Risk Evaluation with the Toxic Substances Control Act

In a recent client alert, Maureen O’Dea Brill and Peter N. Coneski of K&L Gates detail the US Environmental Protection Agency’s (EPA) proposal to revise how it conducts chemical risk evaluations under the Toxic Substances Control Act (TSCA). The move follows Executive Order 14219 and seeks to simplify the current framework while aligning with the administration’s broader interpretation of the Toxic Substances Control Act. The proposal responds to industry criticism that the current process is overly complex and unpredictable, particularly for manufacturers and importers navigating the TSCA inventory.

The EPA uses these evaluations to determine whether chemicals pose unreasonable risks to human health or the environment, considering scientific data across specified conditions of use (COUs). Brill and Coneski note that the agency now intends to reverse its 2024 rule, which required a single, comprehensive risk determination for each chemical. Instead, it plans to return to the pre-2024 approach of evaluating each COU separately, a move consistent with the framework used under the first Trump administration.

Notably, the proposed rule would permit the EPA to consider occupational exposure controls, such as personal protective equipment and engineering safeguards, when assessing chemical risks, an option previously excluded. The rule would also narrow the scope of subpopulations that must be considered, removing “overburdened communities,” and would adopt a new definition of “weight of scientific evidence” drawn from Executive Order 14303.

For compliance professionals, these proposed changes signal a shift toward more flexible, science-focused assessments but also potential legal uncertainty. As Brill and Coneski observe, any final rule is likely to face judicial scrutiny without the deference courts once afforded to agency interpretations.