Agent Name

Hydrogen bromide

CAS Number

10035-10-6

Formula

Br-H

Major Category

Toxic Gases & Vapors

Synonyms

Anhydrous hydrogen bromide; Aqueous hydrogen bromide; Hydrobromic acid; [NIOSH] UN1048; UN1788

Category

Acids, Inorganic

Description

Colorless gas with a sharp, irritating odor. [Note: Shipped as a liquefied compressed gas. Often used in an aqueous solution.]; [NIOSH]

Sources/Uses

Used in synthesis of organic compounds and bromides; also used to dissolve ores and catalyze alkylation; [ACGIH] Dilute HBr used in holography (color bleach); [www.ci.tucson.az.us/arthazards/medium.html]

Comments

Aqueous hydrogen bromide = Hydrobromic acid; [NIOSH] Skin contact with acid solutions may cause burns. HBr, compared to HCl, is more toxic to rats, and considerably more toxic to mice in acute inhalation studies. [ACGIH] Highly corrosive to skin; [Quick CPC] Possible frostbite from contact with liquid; [NIOSH] A corrosive substance that can cause pulmonary edema; [ICSC] The following chemicals can release HBr when spilled in water: Boron tribromide, Phosphorus pentabromide, Acetyl bromide, and Aluminum bromide. [ERG 2012] See the Process, "Toxic Gas from Spilling Chemical in Water." Hydrogen bromide is fibrogenic to the lungs in the context of an acute inhalation exposure complicated by bronchiolitis obliterans.

Exposure Assessment
Skin Designation (ACGIH)

Insufficient data

TIH

Yes

Ceiling (ACGIH)

2 ppm

PEL (OSHA)

3 ppm

MAK

2 ppm

IDLH (NIOSH)

30 ppm

Excerpts from Documentation for IDLHs

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

Odor Threshold Low

2 ppm

Lethal Concentration

LC50 (rat) = 2,858 ppm/1H

Explanatory Notes

Odor threshold from CHEMINFO; The Guide from the Emergency Response Guidebook is for "Hydrogen bromide, anhydrous."

Reference Link

ICSC: Hydrogen bromide

Adverse Effects
Toxic Pneumonitis

Yes

Fibrogenic

Yes

Dermatotoxin

Skin Burns

Links to Other NLM Databases
Health Studies

Human Health Effects from Hazardous Substances Data Bank:

Toxicity Information

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Chemical Information

Search ChemIDplus

Related Information in HazMap
Diseases

Occupational diseases associated with exposure to this agent:

Processes

Industrial Processes with risk of exposure: