Methyl bromide

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 warning properties, so 2% chloropicrin often added; [Olson, p. 321-2] 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); Still being used in US; [Olson, p. 321]
Reference Link #1
Biomedical References

Exposure Assessment

Skin Designation (ACGIH)
Yes
TIH
Yes
TLV (ACGIH)
1 ppm
PEL (OSHA)
Ceiling(OSHA) = 20 ppm
MAK
1 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 (rat) = 302 ppm/8 hr
Explanatory Notes
Odor thresholds from CHEMINFO;
Half Life
Whole body: 16 days; [TDR, p. 842]
NFPA
must be preheated
ERPG-1
Not appropriate
ERPG-2
50 ppm
ERPG-3
200 ppm

Adverse Effects

Toxic Pneumonitis
Yes
Neurotoxin
Other CNS neurotoxin
Hepatotoxin
Hepatoxic (a) from occupational exposure (secondary effect) or (b) in animal studies or in humans after ingestion
Dermatotoxin
Skin burns
IARC Carcinogen
Not classifiable
ACGIH Carcinogen
Not Classifiable

Diseases, Processes, and Activities Linked to This Agent

Diseases

Occupational diseases associated with exposure to this agent:

Processes

Industrial Processes with risk of exposure: