# Hexachlorocyclopentadiene — US federal chemical regulatory reporting thresholds by program (CERCLA, EPCRA, CAA) For Hexachlorocyclopentadiene, cas no. is 77-47-4; cercla rq (lbs) is 10; rcra waste number is U130; regulatory categories is 1,2,3,4, verified against its source on 2026-08-05. - **Substance:** Hexachlorocyclopentadiene _(verified: appears in the quote below)_ - **CAS No.:** 77-47-4 _(verified: appears in the quote below)_ - **CERCLA RQ (lbs):** 10 _(verified: appears in the quote below)_ - **RCRA waste number:** U130 _(verified: appears in the quote below)_ - **Regulatory categories:** 1,2,3,4 _(verified: appears in the quote below)_ - **EPCRA TPQ (lbs):** 100 _(per ecfr.gov, not stated by the source above)_ - **EPCRA RQ (lbs):** 10 _(per ecfr.gov, not stated by the source above)_ ## What the source says > Hexachlorocyclopentadiene | 77-47-4 | 1,2,3,4 | U130 | 10 (4.54) ## What ecfr.gov says > 500/10,000 | 77-47-4 | Hexachlorocyclopentadiene | d | 10 | 100 | Source: https://www.ecfr.gov/current/title-40/chapter-I/subchapter-J/part-355 ## Source - https://www.ecfr.gov/current/title-40/chapter-I/subchapter-J/part-302/section-302.4 - https://www.ecfr.gov/current/title-40/chapter-I/subchapter-J/part-355 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/).