Agent Name |
Methyl bromide |
Alternative Name |
Bromomethane |
CAS Number |
74-83-9 |
Formula |
C-H3-Br |
Major Category |
Pesticides |
Synonyms |
Bromomethane; Monobromomethane; [NIOSH] |
Category |
Fumigants |
Description |
Colorless gas with a chloroform-like odor at high concentrations. [Note: A liquid below 38 degrees F. Shipped as a liquefied compressed gas.] [NIOSH] |
Sources/Uses |
Used as a fumigant, and in the synthesis of organic chemicals; no longer used as a refrigerant or fire extinguisher; [ACGIH] |
Comments |
Liquid causes second degree burns after contact for a few minutes; [CHRIS] Corrosive to skin; [Quick CPC] "Methyl bromide is a neurotoxic gas that can cause convulsions, coma, and long-term neuromuscular and cognitive deficits. Exposure to high concentrations of pure methyl bromide may cause inflammation of the bronchi or lungs, an accumulation of fluid in the lung, and irritation of the eyes and nose." [ATSDR Medical Management] Methyl bromide causes liver injury in acute inhalation studies of laboratory animals. [ACGIH] Acts as an alkylating agent of glutathione and other cellular molecules; Poor warnig properties, so 2% chloropicrin often added; [Olson, p. 264] Effects on the CNS, kidneys, and lungs (possible lung edema after inhalation); [ICSC] |
Restricted |
Use was discontinued as a refrigerant and fire extinguisher because of hazards; [ACGIH] Being phased out as an ozone-depleting chemical: developed nations (2005); undeveloped nations (2015); [Olson, p. 264] |
Reference Link |
ATSDR - ToxFAQs - Bromomethane |
Exposure Assessment |
Skin Designation (ACGIH) |
Yes |
TIH |
Yes |
TLV (ACGIH) |
1 ppm |
PEL (OSHA) | Ceiling(OSHA) = 20 ppm |
IDLH (NIOSH) |
250 ppm |
Excerpts from Documentation for IDLHs |
Other animal data: It has been reported that rats have survived an exposure to 2,600 ppm for 24 minutes [Irish et al. 1940]. . . .Human data: It has been stated that 220 ppm can be endured for several hours without serious effects [Clarke et al. 1945]. |
Odor Threshold Low |
20 ppm |
Odor Threshold High |
1000 ppm |
Lethal Concentration |
LC50 (rats) = 302 ppm/8 hr |
Explanatory Notes |
Odor thresholds from CHEMINFO; |
Half Life |
Whole body: 16 days; [TDR, p. 842] |
Reference Link |
ATSDR Medical Management - Methyl bromide |
Flammability (NFPA) |
1: must be preheated |
Adverse Effects |
Toxic Pneumonitis |
Yes |
Dermatotoxin |
Skin Burns |
Neurotoxin |
Other CNS Neurotoxin |
Hepatotoxin |
Hepatotoxin, Secondary |
IARC Carcinogen |
Not Classifiable |
Links to Other NLM Databases |
Health Studies |
Human Health Effects from Hazardous Substances Data Bank: METHYL BROMIDE
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