# o-Tolidine — workplace exposure limit For o-Tolidine, niosh rel (mg/m³) is C 0.02; cas no. is 119-93-7, verified against its source on 2026-09-08. - **Substance:** o-Tolidine _(verified: appears in its own passage below)_ - **CAS No.:** 119-93-7 _(verified: appears in its own passage below)_ - **NIOSH REL (mg/m³):** C 0.02 _(verified: appears in the quote below)_ ## What the source says > NIOSH REL Ca C 0.02 mg/m3 [60-minute] [skin] ## 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 - o-Tolidine ### CAS No. > CAS No. 119-93-7 ## Source - https://www.cdc.gov/niosh/npg/npgd0618.html Last verified: 2026-09-08. Review by: 2027-09-08. Part of [US workplace chemical exposure limits: federal OSHA, Cal/OSHA and NIOSH, side by side](https://referencesource.org/workplace-exposure-limits/).