EPA Updates Policy to Include All Exposures in Review of New Chemicals Under TSCA
Released on August 22, 2022.
As part of the U.S. Environmental Protection Agency’s (EPA) 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-Harris Administration’s executive orders and directives, the agency has updated its policy to discontinue the use of exposure modeling thresholds when assessing the health and environmental risks of new chemicals under TSCA.
The policy to use these exposure modeling thresholds was put in place in the mid-1990s, to focus limited resources on exposures with the greatest potential to affect human health and the environment. Through the experience of reviewing over a thousand pre-manufacture notices (PMNs) each year, the Program observed that when a chemical is released in relatively small amounts to air or from landfills, that the risks posed by such releases would be small and would not likely be unreasonable – and thus chose to impose exposure release thresholds below which programmatic resources would not be expended to quantify associated risks.
Since then, due in part to the automation of modelling, it has become less burdensome to complete these calculations.
Furthermore, 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.
More completely understanding the potential risks posed by releases of chemicals to overburdened and vulnerable communities is a priority for EPA. Removing the modeling thresholds in the review of new chemicals will help both EPA and overburdened and vulnerable communities better understand these potential risks. Completing the modeling for all potential exposures (rather than only those above an established threshold) that may result from air releases (fugitive and stack from industrial/commercial sites) and releases to groundwater from landfills will allow for a more fulsome understanding of the potential risks to these communities.
To implement this change, the New Chemicals Program will make minimal changes to the coding in our 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 will implement this policy change as soon as feasible. Despite the resource challenges EPA is currently facing in the TSCA program, the agency anticipates that this 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.