Hydrogen fluoride — CAS 7664-39-3 — workplace exposure limit
What is the niosh rel (ppm) for Hydrogen fluoride — CAS 7664-39-3 — workplace exposure limit?
For Hydrogen fluoride, niosh rel (ppm) is TWA 3; niosh rel (mg/m³) is 2.5; cas no. is 7664-39-3, verified against its source on 2026-09-08.
NIOSH REL TWA 3 ppm (2.5 mg/m3) C 6 ppm (5 mg/m3) [15-minute]
— cdc.gov, retrieved 2026-09-08
- Substance
- Hydrogen fluoride verified
- CAS No.
- 7664-39-3 verified
- NIOSH REL (ppm)
- TWA 3 verified
- NIOSH REL (mg/m³)
- 2.5 verified
- PEL (ppm)
- 0.4 per dir.ca.gov
- PEL (mg/m³)
- 0.33 per dir.ca.gov
- STEL (ppm)
- 1 per dir.ca.gov
- STEL (mg/m³)
- 0.83 per dir.ca.gov
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 - Hydrogen fluoride
CAS No.
CAS No. 7664-39-3
— all from cdc.gov, retrieved 2026-09-08
What osha.gov says
Hydrogen fluoride (as F) | 7664-39-3 | - | (2) | - |
— osha.gov, retrieved 2026-08-05
What dir.ca.gov says
7664393 | S | Hydrogen fluoride, as F | 0.4 | 0.33 | | 1 | 0.83
— dir.ca.gov, retrieved 2026-08-05
What dir.ca.gov says
7664393 | | Hydrofluoric acid; see Hydrogen fluoride
— dir.ca.gov, retrieved 2026-08-05
Sources
- cdc.govhttps://www.cdc.gov/niosh/npg/npgd0334.html
- osha.govhttps://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1
- dir.ca.govhttps://www.dir.ca.gov/title8/5155.html