# ANTU — workplace exposure limit For ANTU, niosh rel (mg/m³) is TWA 0.3; cas no. is 86-88-4, verified against its source on 2026-09-08. - **Substance:** ANTU _(verified: appears in its own passage below)_ - **CAS No.:** 86-88-4 _(verified: appears in its own passage below)_ - **NIOSH REL (mg/m³):** TWA 0.3 _(verified: appears in the quote below)_ - **PEL (mg/m³):** 0.3 _(per dir.ca.gov, not stated by the source above)_ ## What the source says > NIOSH REL TWA 0.3 mg/m3 ## Where each value comes from This source states these in separate places, so each value is shown with the passage that states it. ### Substance > CDC - NIOSH Pocket Guide to Chemical Hazards - ANTU ### CAS No. > CAS No. 86-88-4 ## What dir.ca.gov says > 86884 | | ANTU; 1-(1-naphthyl)-2-thiourea; Bantu; Rattrack | -- | 0.3 Source: https://www.dir.ca.gov/title8/5155.html ## What osha.gov says > ANTU (alpha Naphthylthiourea) | 86-88-4 | - | 0.3 | - | Source: https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1 ## Source - https://www.cdc.gov/niosh/npg/npgd0037.html - https://www.dir.ca.gov/title8/5155.html - https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1 Last verified: 2026-09-08. Review by: 2027-08-05. Part of [US workplace chemical exposure limits: federal OSHA, Cal/OSHA and NIOSH, side by side](https://referencesource.org/workplace-exposure-limits/).