EPA Finalizes Changes to TSCA Risk Evaluation Procedures

On May 3, 2024, EPA published a final rule amending the procedures for chemical risk evaluations under the Toxic Substances Control Act (TSCA).  The final rule is largely unchanged from the proposed rule, discussed in a previous Verdant Law blog post.

A key change in the final rule is the requirement that risk determinations end in a single risk determination rather than use-by-use determinations.  EPA previously referred to this approach as a “whole chemical” approach.  However, to address concerns that a single determination of unreasonable risk would mislead the public into believing that all uses present an unreasonable risk, EPA will no longer use the term “whole chemical.”  EPA additionally committed to “identify[ing] the conditions of use that significantly contribute” to the single determination.

Another important change reverts an EPA interpretation of TSCA to a previous interpretation.  EPA proposed that risk evaluations consider all conditions of use in 2017, but determined that the agency had discretion over conditions of use in the final regulation.  However, due to the Ninth Circuit’s 2019 decision in Safer Chemicals, Healthy Families v. EPA, the final rule now mandates the inclusion of all conditions of use in risk evaluations.

Other changes include the removal of the definitions of “best available science” and “weight of the scientific evidence” to allow the agency greater “flexibility to quickly adapt to and implement advancing scientific practices”; EPA’s decision to no longer assume use of personal protective equipment when calculating occupational exposure; and identification of “overburdened communities” as a potentially exposed or susceptible subpopulation.

The final rule, effective July 2, 2024, will apply to ongoing risk evaluations “only to the extent practicable.”