EPA is developing significant new use rules (SNURs) under section 5(a)(2) of the Toxic Substances Control Act (TSCA) on conditions of use identified as not currently ongoing in the final scope documents for the High Priority Substances undergoing TSCA section 6 risk evaluations. EPA is authorized to designate a particular new use (or return of a phased-out use) of a chemical substance as a “significant new use” under TSCA section 5(a)(2) after consideration of relevant factors. Persons subject to the SNUR would be required to notify EPA at least 90 days before commencing any manufacture (including import) or processing of the chemical substance for a significant new use. Once EPA receives a notification, EPA must review and make an affirmative determination on the notification, and take such action as is required by any such determination before the manufacture (including import) or processing for the significant new use can commence. Such a review will assess whether the use may present unreasonable risk to health or the environment and ensure that EPA can prevent future unsafe environmental releases of the chemical substances subject to this SNUR.