# 1,3-Dichloropropene — workplace exposure limit For 1,3-Dichloropropene, niosh rel (ppm) is TWA 1; niosh rel (mg/m³) is 5; cas no. is 542-75-6, verified against its source on 2026-09-08. - **Substance:** 1,3-Dichloropropene _(verified: appears in its own passage below)_ - **CAS No.:** 542-75-6 _(verified: appears in its own passage below)_ - **NIOSH REL (ppm):** TWA 1 _(verified: appears in the quote below)_ - **NIOSH REL (mg/m³):** 5 _(verified: appears in the quote below)_ - **PEL (ppm):** 1 _(per dir.ca.gov, not stated by the source above)_ - **PEL (mg/m³):** 5 _(per dir.ca.gov, not stated by the source above)_ ## What the source says > NIOSH REL Ca TWA 1 ppm (5 mg/m3) [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 - 1,3-Dichloropropene ### CAS No. > CAS No. 542-75-6 ## What dir.ca.gov says > 542756 | S | Dichloropropene | 1 | 5 Source: https://www.dir.ca.gov/title8/5155.html ## Source - https://www.cdc.gov/niosh/npg/npgd0199.html - https://www.dir.ca.gov/title8/5155.html 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/).