An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Reviewing New Chemicals under the Toxic Substances Control Act (TSCA)

Educational Primer on EPA SNUR Programs and Environment and Climate Change Canada/Health Canada SNAc Provisions

This primer provides information and example scenarios meant to serve as an easy-to-follow resource for understanding Significant New Use Rule (SNUR) and Significant New Activity (SNAc) compliance.

You may need a PDF reader to view some of the files on this page. See EPA’s About PDF page to learn more.