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 This website is no longer updated and links to external websites and some internal pages may not work.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 »

Applicability of EPCRA 311 Exemptions To Extremely Hazardous Substances

The definition of a hazardous chemical under EPCRA Section 311 outlines exempted chemicals that are therefore not subject to material safety data sheet (MSDS) reporting or Tier II chemical inventory reporting. Do the exemptions from the definition of hazardous chemical also apply to extremely hazardous substances (EHSs)?

EHSs are a subset of hazardous chemicals; therefore, the exemptions from the definition of hazardous chemical apply to both EHSs and non-EHSs. EHSs are substances subject to emergency planning and hazardous chemical reporting provisions of EPCRA and are defined in EPCRA Section 302. The term hazardous chemical comprises the entire group of substances subject to EPCRA Sections 311 and 312 and is defined as all hazardous chemicals as stated under the Occupational Safety and Health Act (OSHA) and its implementing regulations, but with five exemptions under EPCRA Section 311(e). Therefore, the term hazardous chemical, and the exemptions from the definition, includes both EHSs and non-EHSs.