CAS 7726-95-6





Physical Properties

Dark red-brown liquid

bp 59 °C, mp -7 °C

Slightly soluble in water (3.5 g/100 mL)



Odor can be detected at concentrations as low as 0.05 ppm; exposure to concentrations below 1 ppm causes lacrimation.

Vapor Density

5.5 (air = 1.0)


Vapor Pressure

175 mmHg at 20 °C


Flash Point



Toxicity Data

LD50 oral (rat)

2600 mg/kg


LC50 inhal (rat)

2700 mg/m3



0.1 ppm



0.1 ppm (0.7 mg/m3)



0.3 ppm (2 mg/m3)

Major Hazards

Highly corrosive to skin and eyes; moderately toxic via inhalation; reacts violently with readily oxidized substances.


Bromine is highly corrosive to the skin, causing irritation and destruction with blister formation. If bromine is not removed from the skin immediately, deep-seated ulcers develop, which heal slowly. Severely painful and destructive eye burns may result from contact with either liquid or concentrated vapors of bromine. Bromine is a moderately toxic substance via inhalation. There are good warning properties for bromine: lacrimation begins at ~1 ppm, and 50 ppm is highly irritating to humans. A short exposure (minutes) to 1000 ppm would likely be fatal for humans. Vapor exposures can cause irritation and damage to the upper and lower respiratory tract (nose, throat, and lungs) to varying degrees depending on the concentration. If exposure is sufficiently high, it will cause pulmonary edema, which could lead to death. Other reported symptoms of overexposure include coughing, tightness of chest, nosebleed, headache, and dizziness, followed after some hours by abdominal pain, diarrhea, and a measles-like rash on the trunk and extremities.

Animal studies on the chronic toxicity of bromine revealed disturbances in the respiratory, nervous, and endocrine systems after exposure to 0.2 ppm for 4 months; similar exposure to 0.02 ppm did not produce any adverse effects.

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