# 1,3-Butadiene — US federal chemical regulatory reporting thresholds by program (CERCLA, EPCRA, CAA) For 1,3-Butadiene, cas no. is 106-99-0; cercla rq (lbs) is 10; regulatory categories is 3, verified against its source on 2026-08-05. - **Substance:** 1,3-Butadiene _(verified: appears in the quote below)_ - **CAS No.:** 106-99-0 _(verified: appears in the quote below)_ - **CERCLA RQ (lbs):** 10 _(verified: appears in the quote below)_ - **Regulatory categories:** 3 _(verified: appears in the quote below)_ ## What the source says > 1,3-Butadiene | 106-99-0 | 3 | | 10 (4.54) ## 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/).