Review of generic scenario environmental release and occupational exposure models used in chemical risk assessment

Abstract

Under the Toxic Substances Control Act (TSCA), the United States Environmental Protection Agency (USEPA) is required to determine whether a new chemical substance poses an unreasonable risk to human health or the environment before the chemical is manufactured in or imported into the United States. This manuscript provides a review of the process used to evaluate the risk associated with a chemical based on the scenarios and models used in the evaluation. Specifically, the Generic Scenarios and Emission Scenario Documents developed by the USEPA were reviewed, along with background documentation prepared by USEPA to identify the core elements of the environmental release and occupational exposure scenarios used to assess the risk of the chemical being evaluated. Additionally, this contribution provides an overview of methods used to model occupational exposures and environmental releases as part of the chemical evaluation process used in other jurisdictions, along with work being performed to improve these models. Finally, the alternative methods to evaluate occupational exposures and environmental releases that may be used as part of the decision-making process regarding a chemical are identified. The contribution provides a path forward for reducing the time required and improving the chemical evaluation of the unreasonable risk determination regarding the manufacture or import of a chemical.

Keywords:

• Chemical safety
• chemical use
• environmental release scenario
• exposure scenario
• generic models

Disclaimers

The views expressed in this article are those of the authors and do not necessarily represent the views or policies of the U.S. Environmental Protection Agency.

Acknowledgments

The authors acknowledge OPPT Engineering Technical Team, Majd El-Zoobi, Rehan Choudhary, Ariel Hou, Emad Al-Haddad, Nicholas Suek, and Hom Sharma for their review of this manuscript to ensure that it was consistent with OPPT practices.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

No data were developed for the contribution.