# NIOSH Pocket Guide to Chemical Hazards
Hydrogen fluoride | CAS 7664-39-3
HF | RTECS MW7875000
Synonyms & Trade Names Anhydrous hydrogen fluoride; Aqueous hydrogen fluoride (i.e., Hydrofluoric acid); HF-A | DOT ID & Guide 1052 125 (anhydrous) 1790 157 (solution)
Exposure Limits | NIOSH REL: TWA 3 ppm (2.5 mg/m3) C 6 ppm (5 mg/m3) [15-minute]
OSHA PEL†: TWA 3 ppm
IDLH 30 ppm | Conversion 1 ppm = 0.82 mg/m3
Physical Description Colorless gas or fuming liquid (below 67°F) with a strong, irritating odor. [Note: Shipped in cylinders.]
MW: 20.0 | BP: 67°F | FRZ: -118°F | Sol: Miscible
VP: 783 mmHg | IP: 15.98 eV | RGasD: 1.86 | Sp.Gr: 1.00 (Liquid at 67°F)
Fl.P: NA | UEL: NA | LEL: NA |
Nonflammable Gas
Incompatibilities & Reactivities Metals, water or steam [Note: Corrosive to metals. Will attack glass and concrete.]
Measurement Methods NIOSH 7902, 7903, 7906; OSHA ID110
Personal Protection & Sanitation Skin: Prevent skin contact (liquid) Eyes: Prevent eye contact (liquid) Wash skin: When contaminated (liquid) Remove: When wet or contaminated (liquid) Change: No recommendation Provide: Eyewash (liquid), Quick drench (liquid) | First Aid (See procedures) Eye: Irrigate immediately (solution/liquid) Skin: Water flush immediately (solution/liquid) Breathing: Respiratory support Swallow: Medical attention immediately (solution)
Respirator Recommendations NIOSH/OSHA Up to 30 ppm: (APF = 10) Any chemical cartridge respirator with cartridge(s) providing protection against the compound of concern*/(APF = 25) Any powered, air-purifying respirator with cartridge(s) providing protection against the compound of concern*/(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted canister providing protection against the compound of concern/(APF = 10) Any supplied-air respirator*/(APF = 50) Any self-contained breathing apparatus with a full facepiece Emergency or planned entry into unknown concentrations or IDLH conditions: (APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode/(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus Escape: (APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted canister providing protection against the compound of concern/Any appropriate escape-type, self-contained breathing apparatus
Exposure Routes inhalation, skin absorption (liquid), ingestion (solution), skin and/or eye contact
Symptoms Irritation eyes, skin, nose, throat; pulmonary edema; eye, skin burns; rhinitis; bronchitis; bone changes
Target Organs Eyes, skin, respiratory system, bones
See also: INTRODUCTION