On October 18, 2022, the U.S. Environmental Protection Agency’s (EPA) New Chemicals Program held a webinar on EPA’s process for assessing the potential risks of new chemicals under Section 5 of the Toxic Substances Control Act (TSCA) and the types of data EPA considers in this assessment. Specifically, the webinar covered examples of data (quantitative and qualitative) that are not likely to be accepted for engineering assessment, considerations EPA makes when evaluating data, and clarifications of common misconceptions in EPA’s new chemical assessments. The webinar was the second in a series of webinars intended to increase the efficiency and transparency of EPA’s new chemical determinations. EPA will hold a third webinar to communicate additional information intended to help submitters of new chemicals supplement complete initial review submissions. EPA will post information on the third webinar as it becomes available. In July 2022, EPA hosted the first webinar, analyzing common issues that cause EPA to have to rework risk assessments. More information on the first webinar is available in our July 28, 2022, memorandum. The slides for the second webinar are available online.

The webinar included several case studies from past TSCA Section 5 submissions. The case studies discuss how EPA evaluates submitted information and determines whether it is acceptable for the engineering assessment. According to EPA, worker inhalation exposure from particulates is a frequent area of rework. EPA selected several case studies to cover situations where submitter claims were either accepted or not accepted and provided rationales for each type of determination. EPA expects manufacturing, processing, and use operations involving handling, transferring, unloading, or loading the new chemical substances (NCS) in solid forms to present potential exposure for workers to total and respirable particles. In the absence of specific and substantiated information from the submitter, EPA will assess inhalation exposure to total and respirable particulates using either the applicable Organization for Economic Cooperation and Development (OECD) Emission Scenario Documents (ESD) or the Occupational Safety and Health Administration (OSHA) Particulates Not Otherwise Regulated (PNOR) Total and Respirable Dust, Permissible Exposure Limit (PEL) Model.

A more detailed summary of the webinar and an insightful commentary are available in our October 25, 2022, memorandum.