Challenges and Opportunities: Assessing Exposure to Chemical Substances under Amended TSCA

摘要

Under the 2016 Lautenberg Chemical Safety Act amendments to the U.S. Toxic Substances Control Act (TSCA), data and information about both hazard and exposure potential will be central to EPA's risk based decision-making about TSCA chemicals. Under the amended law, EPA will evaluate chemicals under their conditions of use. As a result, exposure considerations, in particular, will be critical both to EPA's designation of chemicals as high or low priority for risk evaluations and in subsequent EPA risk evaluations of high priority chemicals. In recent years, exposure science measurement and predictive capabilities have advanced significantly. New understandings have evolved in 21st century hazard and exposure science. These developments include: - REACH tools on exposure assessment - Updated and new EPA exposure assessment models and tools - OECD approaches to harmonizing use categories and exposure scenarios - High Throughput (HTP) approaches to exposure that complement HTP toxicity testing All of these advances are useful to consider for integrating into transparent, consistent approaches to regulatory risk-based decision-making. This will enable both efficiency and credibility in regulatory decision-making. Learnings from experience to date with these new methodologies and tools will be discussed, focusing on relevance to TSCA.