# Phosphorodithioic acid, O,O-diethyl S-[2-(ethylthio)ethyl] ester — US federal chemical regulatory reporting thresholds by program (CERCLA, EPCRA, CAA) For Phosphorodithioic acid, O,O-diethyl S-[2-(ethylthio)ethyl] ester, cas no. is 298-04-4; cercla rq (lbs) is 1; rcra waste number is P039; regulatory categories is 1,4, verified against its source on 2026-08-05. - **Substance:** Phosphorodithioic acid, O,O-diethyl S-[2-(ethylthio)ethyl] ester _(verified: appears in the quote below)_ - **CAS No.:** 298-04-4 _(verified: appears in the quote below)_ - **CERCLA RQ (lbs):** 1 _(verified: appears in the quote below)_ - **RCRA waste number:** P039 _(verified: appears in the quote below)_ - **Regulatory categories:** 1,4 _(verified: appears in the quote below)_ ## What the source says > Phosphorodithioic acid, O,O-diethyl S-[2-(ethylthio)ethyl] ester | 298-04-4 | 1,4 | P039 | 1 (0.454) ## 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/).