Hydrogen bromide

May 1994
Immediately Dangerous to Life or Health Concentrations (IDLH)

CAS number: 10035–10–6

NIOSH REL: 3 ppm (10 mg/m3) CEILING

Current OSHA PEL: 3 ppm (10 mg/m3) TWA

1989 OSHA PEL: 3 ppm (10 mg/m3) CEILING

1993-1994 ACGIH TLV: 3 ppm (9.9 mg/m3) CEILING

Description of Substance: Colorless gas with a sharp, irritating odor.

LEL:. . Nonflammable Gas

Original (SCP) IDLH: 50 ppm

Basis for original (SCP) IDLH: Hydrogen bromide is an extremely irritating and corrosive gas. The chosen IDLH is based on an analogy with bromine. According to ILO [1971], however, bromine produces a more marked toxic action. AIHA [1958] reported that for humans, 40 to 60 ppm bromine is dangerous for short exposure [Henderson and Haggard 1943]. Because hydrogen bromide is considered less irritating than bromine, an IDLH of 50 ppm is chosen.

Short-term exposure guidelines: None developed


Lethal concentration data:

Species Reference LC50(ppm) LCLo(ppm) Time Adjusted 0.5-hrLC (CF) Derivedvalue
RatMouse Back et al. 1972Back et al. 1972 2,858814 ———- 1 hr1 hr 3,573 ppm (1.25)1,018 ppm (1.25) 357 ppm102 ppm


Other animal data: Hydrogen bromide (with a rat 1-hour LC50 of 2,858 ppm [Back et al. 1972]) is about as acutely toxic as hydrogen chloride (with a rat 1-hour LC50 of 3,124 ppm [MacEwen and Vernot 1974]).

Human data: Volunteers noted nose and throat irritation at 2 to 6 ppm after several minutes [Clayton and Clayton 1981]. It has been reported that 1,300 to 2,000 ppm are lethal in exposures lasting a few minutes [NRC 1981].



1. AIHA [1958]. Bromine. In: Hygienic guide series. Am Ind Hyg Assoc J 19:349-350.

2. Back KC, Thomas AA, MacEwen JD [1972]. Reclassification of materials listed as transportation health hazards. Wright-Patterson Air Force Base, OH: 6570th Aerospace Medical Research Laboratory, Report No. TSA-20-72-3, pp. A-216 to A-217.

3. Clayton GD, Clayton FE, eds. [1981]. Patty’s industrial hygiene and toxicology. 3rd rev. ed. Vol. 2B. Toxicology. New York, NY: John Wiley & Sons, Inc., p. 2970.

4. Henderson Y, Haggard HW [1943]. Noxious gases. 2nd ed. New York, NY: Reinhold Publishing Corporation, p. 133.

5. ILO [1971]. Chlorine and compounds. In: Encyclopaedia of occupational health and safety. 2nd ed. Vol. I (A-K). Geneva, Switzerland: International Labour Office, pp. 211-213.

6. MacEwen JD, Vernot EH [1974]. Toxic Hazards Research Unit annual report: 1974. Wright-Patterson Air Force Base, OH: Air Force Systems Command, Aerospace Medical Division, Aerospace Medical Research Laboratory Report, AMRL-TR-74-78.

7. NRC [1981]. Prudent practices for handling hazardous chemicals in laboratories. Washington, DC: National Academy of Sciences, National Research Council, p. 98.

Page last reviewed: December 4, 2014