# Sodium fluoride (as F) — workplace exposure limit For Sodium fluoride (as F), niosh rel (mg/m³) is TWA 2.5; cas no. is 7681-49-4, verified against its source on 2026-09-08. - **Substance:** Sodium fluoride (as F) _(verified: appears in its own passage below)_ - **CAS No.:** 7681-49-4 _(verified: appears in its own passage below)_ - **NIOSH REL (mg/m³):** TWA 2.5 _(verified: appears in the quote below)_ ## What the source says > NIOSH REL TWA 2.5 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 - Sodium fluoride (as F) ### CAS No. > CAS No. 7681-49-4 ## Source - https://www.cdc.gov/niosh/npg/npgd0563.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/).