On December 28, 2023, the U.S. Environmental Protection Agency (EPA) released comments from the letter peer review for its 2023 white paper presenting EPA’s quantitative approach for the human health risk assessment for part 2 of the Toxic Substances Control Act (TSCA) risk evaluation for asbestos. EPA notes in its December 28, 2023, press release that under the previous Administration, it narrowed the scope of the asbestos risk evaluation by reviewing only ongoing uses and excluding legacy uses and disposals. Because only chrysotile asbestos has ongoing uses, EPA did not consider other fiber types. In 2019, a court ruled that EPA unlawfully excluded “legacy uses” and “associated disposal” from TSCA’s definition of “conditions of use,” however, resulting in the need to supplement EPA’s initial review of asbestos (“part 1”) with a “part 2” risk evaluation focused on legacy uses and associated disposals. Part 2 also includes other types of asbestos fibers in addition to chrysotile (crocidolite, amosite, anthophyllite, tremolite, and actinolite) and asbestos-containing talc.

In August 2023, EPA released a white paper for public comment and letter peer review identifying existing hazard values for asbestos and describing how the Agency proposes to use them in the risk evaluation. EPA also described its systematic review approach to identify and evaluate relevant scientific studies for the quantification of asbestos hazards and to make decisions about which are most relevant for part 2 of the risk evaluation in a fit-for-purpose manner. Consistent with EPA and Office of Management and Budget (OMB) guidance on peer review of scientific and technical work products, EPA requested a letter peer review by independent experts of the quantitative approach to the human health assessment to be used in part 2 of the risk evaluation. EPA states that it submitted the white paper, rather than the full draft risk evaluation, for peer review to focus on key technical aspects of the forthcoming risk evaluation and to make the most efficient use of the experts’ time. According to EPA, the peer review comments will help shape its asbestos part 2 risk evaluation, which the Agency plans to release for public comment in early 2024.