EPA New Chemicals Program Will Discontinue Use of Exposure Modeling Thresholds When Assessing Health and Environmental Risks
By Lynn L. Bergeson and Carla N. Hutton
The U.S. Environmental Protection Agency (EPA) announced on August 22, 2022, that as part of its commitment to re-evaluate policies and practices under the Toxic Substances Control Act (TSCA) New Chemicals Program to ensure they adhere to statutory requirements and the Biden Administration’s executive orders and directives, it has updated its policy to discontinue the use of exposure modeling thresholds when assessing the health and environmental risks of new chemicals under TSCA. According to EPA, due in part to the automation of modeling, it has become less burdensome to complete these calculations. Furthermore, according to EPA, removing the thresholds supports President Biden’s Executive Order 13985, “Advancing Racial Equity and Support for Underserved Communities Through the Federal Government,” which calls on federal agencies to advance equity, including by reviewing and revising as needed government policies and programs impacting underserved communities.
The New Chemicals Program will implement this change by making minimal changes to the coding in the New Chemical Review application to remove the thresholds and will update standard operating procedures and training materials for exposure and human health risk assessors. EPA states that it will implement this policy change “as soon as feasible.” According to EPA, despite the resource challenges it is currently facing in the TSCA program, it anticipates that the change “will have minimal impact on the amount of time it takes to complete new chemical reviews and that the benefits gained from a more comprehensive accounting of all potential air and water releases will help ensure any needed protections are in place before a new chemical can come to market.”
More information and a detailed commentary that discusses thresholds of toxicological concern (TTC) are available in our August 22, 2022, memorandum.