HYDROGEN FLUORIDE†

Chemical Identification
Chemical Identification
CAS # 7664-39-3
Formula

HF (aqueous)

Synonyms

anhydrous hydrofluoric acid, HF-A

Physical Properties
Physical Properties
Physical description Colorless gas or fuming liquid (below 67°F) with a strong, irritating odor.
Boiling point 67°F Molecular weight 20
Freezing point/melting point -118°F Vapor pressure 783 mmHg
Flash point Vapor density 1.86
Specific gravity 1 Ionization potential 15.98 eV
Lower explosive limit (LEL) Upper explosive limit (UEL)
NFPA health rating 4 NFPA fire rating 0
NFPA reactivity rating 1 NFPA special instruction
Vapor hazard ratio (VHR)
Historical exceedance percentage
Target organs
Monitoring Methods Used by OSHA
Monitoring Methods Used by OSHA
Analyte code (IMIS no.) 1460
Sampling group
Sampler/Sampling media Mixed cellulose ester filter (MCEF) 0.8 micron (37 mm) and filter spacer with Na₂CO₃ impregnated backup pad, in a 3-piece cassette [SKC 225-9001]
Sampling time*

60 min

Sampling volume (TWA)*

90 L

Sampling flow rate (TWA)*

1.5 L/min

Sampling volume (STEL/Peak/C)*

22.5 L

Sampling flow rate (STEL/Peak/C)*

1.5 L/min

Analytical method instruments ISE
Method reference OSHA ID-110 (partially validated)
Notes

Submit as a separate sample (Particulate F- on MCEF, HF on impregnated backup pad). The filter and filter spacer reside in one section while the impregnated backup pad is in another section of a 3-piece polystyrene cassette.

The filter and backup pad should not have physical contact with one another. When analysis of a compound is requested, an analysis is performed for fluoride (F-) and reported as the compound. Hydrogen fluoride is collected on a Na₂CO₃ impregnated backup pad.

Special requirements

* All sampling instructions above are recommended guidelines for OSHA Compliance Safety and Health Officers (CSHOs), please see the corresponding OSHA method reference for complete details.

Wipe Method
Wipe Method
Sampler/Sampling media
Bulk Method
Bulk Method
On-Site Screening Techniques
On-Site Screening Techniques
Device
Model/Type
Sampling information
(see manufacturer instructions)
Exposure Limits
Exposure Limits
OSHA PEL
8-hour TWA
(ST) STEL
(C) Ceiling
Peak
NIOSH REL
Up to 10-hour TWA
(ST) STEL
(C) Ceiling
ACGIH TLV©
8-hour TWA
(ST) STEL
(C) Ceiling
CAL/OSHA PEL
8-hour TWA
(ST) STEL
(C) Ceiling
Peak
PEL-TWA

3 ppm (2 mg/m³)

REL-TWA

3 ppm (2 mg/m³)

TLV-TWA

0.5 ppm [2004]

PEL-TWA

0.4 ppm (0.33 mg/m³)

PEL-STEL REL-STEL TLV-STEL PEL-STEL

1 ppm (0.83 mg/m³)

PEL-C REL-C

6 ppm (5 mg/m³) [15 minutes]

TLV-C

2 ppm [2004]

PEL-C
Skin notation

N

Skin notation

Y

Skin notation

Y

Skin notation

Y

Notes:

See 29 CFR 1910.1000 Table Z-2

Notes: Notes:

BEI®

Notes:
Health factors:  See NIH-NLM PubChem. IDLH

30 ppm

Carcinogenic classifications: Not listed Notes:
AIHA emergency response planning guidelines - ERPG-1/ERPG-2/ERPG-3:

2 ppm/20 ppm/50 ppm

Additional Resources and Literature References
Additional Resources and Literature References

NOAA: CAMEO Chemicals - Hydrofluoric acid, solution

NIOSH: Pocket Guide to Chemical Hazards - Hydrogen fluoride

Literature References

  • EPA: Hazard Summary - Hydrogen Fluoride.
  • ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) - Hydrogen Fluoride. See annual publication for most recent information.
  • ANSI (formerly United States of America Standards Institute): USA Standard Acceptable Concentrations of Hydrogen Fluoride and Inorganic Fluoride Dusts. November 9, 1966.
  • California Occupational Safety & Health Standards Board: Initial and Final Statement of Reasons. March 17, 2012.
  • Lund K et al Exposure to hydrogen fluoride: an experimental study in humans of concentrations of fluoride in plasma, symptoms, and lung function. Occup Environ Med 1997;54:32-37
  • NIOSH: Criteria for a Recommended Standard - Occupational Exposure to Hydrogen Fluoride. March 1976.
  • NIOSH: Occupational Health Guideline for Hydrogen Fluoride. September 1978.

Last Updated Date : 12/31/2020