Hydrogen fluoride (as F)
Immediately Dangerous to Life or Health Concentrations (IDLH)
CAS number: 7664–39–3
NIOSH REL: 3 ppm (2.5 mg/m3) TWA, 6 ppm (5 mg/m3) 15-minute CEILING
Current OSHA PEL: 3 ppm TWA
1989 OSHA PEL: 3 ppm TWA, 6 ppm STEL
1993-1994 ACGIH TLV: 3 ppm (2.6 mg/m3) CEILING
Description of Substance: Colorless gas or fuming liquid (below 67°F) with a strong, irritating odor.
LEL:. . Nonflammable Gas/Noncombustible Liquid
Original (SCP) IDLH: 30 ppm
Basis for original (SCP) IDLH: The chosen IDLH is based on the statement by Patty  that 24 mg/m3 (30 ppm) was tolerated by animals for a total of 41 hours without a fatality [Machle et al. 1934]. A concentration of 50 ppm is obviously too high to be selected as the IDLH, because Deichmann and Gerarde  stated that 50 ppm may be fatal when inhaled for 30 to 60 minutes.
Existing short-term exposure guidelines: National Research Council (NRC) Emergency Exposure Limits (EELs) recommended to military and space agencies [Smyth 1966]
10-minute EEL: 20 ppm
30-minute EEL: 10 ppm
60-minute EEL: 8 ppm
ACUTE TOXICITY DATA:
Lethal concentration data:
|Species||Reference||LC50 (ppm)||LCLo (ppm)||Time||Adjusted 0.5-hr LC (CF*)||Derived value|
|Rat||Darmer et al. 1972||1,276||—–||1 hr||1,799 ppm (1.41)||180 ppm|
|Monkey||MacEwen & Vernot 1970||1,774||—–||1 hr||2,501 ppm (1.41)||250 ppm|
|Rabbit||Treon et al. 1950||—–||313||7 hr||1,171 ppm (3.74)||117 ppm|
|G. pig||Wohlslagel et al. 1976||4,327||—–||15 min||3,072 ppm (0.71)||307 ppm|
*Note: Conversion factor (CF) was determined with “n” = 2.0 [ten Berge et al. 1986].
Other animal data: Guinea pigs and rabbits survived exposures to 30 ppm for 41 hours, but exposures to 300 ppm for 2 hours or more were fatal [Machle et al. 1934].
It has been stated that 50 ppm may be fatal when inhaled for 30 to 60 minutes [Deichmann and Gerarde 1969]. Volunteers tolerated concentrations as high as 4.7 ppm for 6 hours per day for 10 to 50 days without severe adverse effects [Largent 1961].
|Revised IDLH: 30 ppm [Unchanged]Basis for revised IDLH: Based on acute inhalation toxicity data in humans [Deichmann and Gerarde 1969; Largent 1961] and animals [Machle et al. 1934], the original IDLH for hydrogen fluoride (30 ppm) is not being revised at this time.|
1. Darmer KI Jr, Haun CC, MacEwen JD . The acute inhalation toxicology of chlorine pentafluoride. Am Ind Hyg Assoc J 33:661-668.
2. Deichmann WB, Gerarde HW . Hydrofluoric acid (hydrogen fluoride, HF). In: Toxicology of drugs and chemicals. New York, NY: Academic Press, Inc., pp. 317-318.
3. Largent EJ . Fluorosis. The health aspects of fluorine compounds. Columbus, OH: Ohio State University Press, pp. 34-39, 43-48.
4. MacEwen JD, Vernot EH . Toxic hazards research unit annual report: 1970. Wright-Patterson Air Force Base, OH: Aerospace Medical Research Laboratory, AMRL-TR-70-77.
5. Machle W, Thamann F, Kitzmiller K, Cholak J . The effects of the inhalation of hydrogen fluoride. I. The response following exposure to high concentrations. J Ind Hyg Toxicol 16(2):129-145.
6. Patty FA, ed. . Industrial hygiene and toxicology. 2nd rev. ed. Vol. II. Toxicology. New York, NY: Interscience Publishers, Inc., p. 842.
7. Smyth HF Jr . Military and space short-term inhalation standards. Arch Environ Health 12:488-490.
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9. Treon JF, Dutra FR, Cappel J, Sigmon H, Younker W . Toxicity of sulfuric acid mist. AMA Arch Ind Hyg Occup Med 2:716-734.
10. Wohlslagel J, Dipasquale LC, Vernot EH . Toxicity of solid rocket motor exhaust: effects of Hcl, HF, and alumina on rodents. J Combustion Toxicol 3:61-70.