Proposed rule · 2026-10161

Significant New Use Rules on Certain Chemical Substances (26-2); Extension of Comment Period

EPA issued significant new use rules (SNURs) under the Toxic Substances Control Act (TSCA) on April 24, 2026, for chemical substances subject to an Order issued pursuant to TSCA. The SNURs require persons to notify EPA at least 90 days before commencing the manufacture (defined by statute to include import) or processing of any of these chemical substances for an activity that is designated as a significant new use in the SNUR. The required notification initiates EPA's evaluation of the conditions of that use for that chemical substance. In addition, the manufacture or processing for new use may not commence until EPA has conducted a review of the required notification; made an appropriate determination regarding that notification; and taken such actions as required by that determination. This document extends the comment period, which was scheduled to end on May 26, 2026, for 45 days.