# Hexachloropropene — US federal chemical regulatory reporting thresholds by program (CERCLA, EPCRA, CAA) For Hexachloropropene, cas no. is 1888-71-7; cercla rq (lbs) is 1000; rcra waste number is U243; regulatory categories is 4, verified against its source on 2026-08-05. - **Substance:** Hexachloropropene _(verified: appears in the quote below)_ - **CAS No.:** 1888-71-7 _(verified: appears in the quote below)_ - **CERCLA RQ (lbs):** 1000 _(verified: appears in the quote below)_ - **RCRA waste number:** U243 _(verified: appears in the quote below)_ - **Regulatory categories:** 4 _(verified: appears in the quote below)_ ## What the source says > Hexachloropropene | 1888-71-7 | 4 | U243 | 1000 (454) ## Source - https://www.ecfr.gov/current/title-40/chapter-I/subchapter-J/part-302/section-302.4 Last verified: 2026-08-05. Review by: 2027-08-05. Part of [US federal chemical regulatory reporting thresholds by program (CERCLA, EPCRA, CAA)](https://referencesource.org/chemical-regulatory-reporting-thresholds/).