The EPA has release a proposed guidance document for conducting cumulative risk assessments (“CRA”) under the Toxic Substances Control Act (“TSCA”). The guidance is designed to assist the EPA to characterize and quantify the combined risk to health and/or the environment from multiple chemical agents and/or stressors.

Under the Biden Administration, consideration of cumulative risk is a top priority for the EPA in its efforts to address environmental justice concerns. The draft guidance notes that disadvantage communities often face multiple pollutants from multiple media which overlap with the adverse effects of poverty and other socioeconomic factors.

However, it takes a limited view of those stressors noting that it is unable to quantify risk from non-chemical factors such as racism or poverty. Instead, the EPA relies upon authority under TSCA which allows it to conduct risk evaluations consistent with “best available science,” which in some instances necessitate the performance of cumulative exposure analysis.

The document notes that, because individuals are co-exposed to many chemicals in their daily lives, some of which have similar health effects, the most appropriate approach is to assess risk to human health from exposure to multiple chemicals. For purposes of grouping chemicals for CRA, the document states that the EPA will consider toxicological similarity, and evidence of co-exposure over a relevant time frame.

The public comment period on the draft proposal will close on April 27, 2023.