# beta-Propiolactone — US federal chemical regulatory reporting thresholds by program (CERCLA, EPCRA, CAA) For beta-Propiolactone, cas no. is 57-57-8; cercla rq (lbs) is 10; regulatory categories is 3, verified against its source on 2026-08-05. - **Substance:** beta-Propiolactone _(verified: appears in the quote below)_ - **CAS No.:** 57-57-8 _(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)_ - **EPCRA TPQ (lbs):** 500 _(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 > beta-Propiolactone | 57-57-8 | 3 | | 10 (4.54) ## What ecfr.gov says > 10 | 57-57-8 | Propiolactone, Beta- | | 10 | 500 | 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/).