Final Rule Outlines Changes to EPA’s Risk Evaluation Process

A new rule finalized on April 23 by EPA will codify changes to the agency’s process for conducting chemical risk evaluations under the Toxic Substances Control Act (TSCA). According to EPA, the rule includes clarifications intended to ensure that it “appropriately considers risks to all workers in its risk evaluations.” For example, the agency will not assume that workers always use personal protective equipment when conducting its chemical risk evaluations, although EPA acknowledges that many employers take action to protect their employees. EPA previously adopted this approach in 2021 and has incorporated it into its TSCA risk evaluation activities in recent years. The agency will also consider “reasonably available information” such as circumstances where subpopulations of workers are exposed to a chemical substance due to a lack or ineffective use of PPE, a pre-publication copy of the final rule (PDF) explains.

The rule will also formalize EPA’s revised approach to risk determination. Rather than determining risk based on each “condition of use” for a chemical substance, the agency will make a single determination regarding whether a substance presents an “unreasonable risk” to human health or the environment. When EPA determines unreasonable risk associated with a chemical substance, the agency says it will identify the conditions of use that “significantly contribute” to its determination.

Additional changes codified under the final rule include a requirement that risk evaluations not exclude any conditions of use or exposure pathways as well as new procedures and criteria regarding whether and how EPA will revise its scope and risk evaluation documents. The agency also describes its plan to consider “real-world exposure scenarios,” including multiple exposure pathways to the same chemical substance and combined risks from multiple chemicals, when it has the information to do so. EPA’s news release states that these scenarios “may be particularly important for communities who face greater exposures or susceptibilities to chemicals than the rest of the general population.”

EPA will apply the procedures from the final rule to all risk evaluations initiated 30 days after the rule is published in the Federal Register or later. The agency intends to apply its new procedures to risk evaluations that are currently in process “to the extent practicable.”

More information can be found in EPA’s news release and on the agency’s webpage for risk evaluations for existing chemicals under TSCA. A pre-publication version of the final rule is also available as a PDF.