Prior to manufacture or importation into the United States, new chemicals must undergo regulatory review to evaluate human and ecological risk. This requires assessments of environmental persistence, transport, and bioaccumulation/bioconcentration, among other factors. The U.S. Environmental Protection Agency’s Office of Pollution Prevention and Toxics (EPA/OPPT) assesses approximately 1,000 new chemicals per year under the Toxic Substances Control Act (TSCA, amended by the Lautenberg Chemical Safety Act), but does not routinely receive measured data on fate and transport. Thus, EPA/OPPT scientists use models to inform fate and transport assessments and decisions regarding new chemicals. These models predict a wide range of chemical attributes and vary in methodology, performance, and data sources. This talk will describe how persistence and bioaccumulation models are incorporated into risk assessment of new chemicals. EPA models, such as EPI Suite™, are commonly used both in EPA/OPPT activities and by other organizations, and some modules in EPI Suite™ are currently undergoing significant science and functionality updates. EPA/OPPT models are based on publicly-available data as well as thousands of confidential studies submitted with Pre-Manufacture Notifications, a rich data source which is not available outside of EPA/OPPT. However, every model is limited by the chemical domain for which it was designed. For example, in the case of most EPI Suite™ modules, compounds with molecular weight above 500 Daltons or those containing metal atoms are not well-represented in the training set. Further, there are opportunities for additional environmental fate models to contribute to new chemical assessments, if they meet TSCA program goals including transparency in model methodology, availability to stakeholders, and protection of confidential business information. The views expressed in this abstract are those of the authors and do not represent Agency policy or endorsement.

Use of environmental fate models in U.S. EPA TSCA new chemicals assessments

253rd National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.