Methyl bromide

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]

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

Yes

Yes

1 ppm

Ceiling(OSHA) = 20 ppm

1 ppm

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].

20 ppm

Odor Threshold High

1000 ppm

LC50 (rat) = 302 ppm/8 hr

Explanatory Notes

Odor thresholds from CHEMINFO;

Whole body: 16 days; [TDR, p. 842]

Reference Link #2

must be preheated

Not appropriate

50 ppm

200 ppm

Yes

Other CNS neurotoxin

Hepatoxic (a) from occupational exposure (secondary effect) or (b) in animal studies or in humans after ingestion

Skin burns

Not classifiable

Not Classifiable

Diseases

Occupational diseases associated with exposure to this agent:

• Fumigants, acute toxic effect
• Pneumonitis, toxic

Processes

Industrial Processes with risk of exposure:

• Farming (Pesticides)