74-83-9 Methyl bromide

Name: Methyl bromide
Synonyms: Bromomethane
CAS Number:74-83-9
Molecular Formula:CH₃Br
Molecular Weight:94.95
EINECS:200-813-2
Density:1.732
Boiling Point:3.56 ºC
Flash Point:-34 ºC
Safety Description:Suspected carcinogen with experimental carcinogenic data. A human poison by inhalation. Human systemic effects by inhalation: anorexia, nausea or vomiting. Corrosive to skin; can produce severe burns. Human mutation data reported. A powerful fumigant gas that is one of the most toxic of the common organic halides. It is hemotoxic and narcotic with delayed action. The effects are cumulative and damaging to nervous system, kidneys, and lung. Central nervous system effects include blurred vision, mental confusion, numbness, tremors, and speech defects.

Methyl bromide is reported to be eight times more toxic on inhalation than ethyl bromide. Moreover, because of its greater volatility, it is a much more frequent cause of poisoning. Death following acute poisoning is usually caused by its irritant effect on the lungs. In chronic poisoning, death is due to injury to the central nervous system. Fatal poisoning has always resulted from exposure to relatively high concentrations of methyl bromide vapors (from 8600 to 60,000 ppm). Nonfatal poisoning has resulted from exposure to concentrations as low as 100–500 ppm. In addition to injury to the lung and central nervous system, the kidneys may be damaged, with development of albuminuria and, in fatal cases, cloudy swelling and/or tubular degeneration. The liver may be enlarged. There are no characteristic blood changes.

Mixtures of 10–15 percent with air may be ignited with difficulty. Moderately explosive when exposed to sparks or flame. Forms explosive mixtures with air within narrow limits at atmospheric pressure, with wider limits at higher pressure. The explosive sensitivity of mixtures with air may be increased by the presence of aluminum, magnesium, zinc, or their alloys. Incompatible with metals, dimethyl sulfoxide, ethylene oxide. To fight fire, use foam, water, CO₂, dry chemical. When heated to decomposition it emits toxic fumes of Br⁻. See also BROMIDES.

Analytical Methods:

   

For occupational chemical analysis use NIOSH: Methyl Bromide, 2520.
liansport Information:UN 1062/1581/1647/1955