What Is Methyl Bromide?
Methyl bromide (CH3Br), also known as bromomethane, is a type of alkyl halide recognized under various classifications for its hazardous properties by the Industrial Safety and Health Law. It is also categorized as a disease-causing chemical substance under the Labor Standards Law and a Class 1 Designated Chemical Substance under the PRTR Law, requiring careful handling.
Uses of Methyl Bromide
Previously a widespread fumigant for soil disease and weed control, and quarantine treatments, methyl bromide was identified as an ozone-depleting substance in 1992. Its use was phased out in developed countries by 2005 and in developing countries by 2015, except for quarantine and pre-shipment processes which are not regulated.
Properties of Methyl Bromide
1. Physical Properties
A colorless, odorless gas, methyl bromide has a melting point of -93.66°C and a boiling point of 4°C. It is highly flammable, with a spontaneous combustion temperature of 537°C and an explosive range of 10 to 16 vol%. It is heavier than air, with specific gravity indicating its density as a liquid.
2. Chemical Properties
Methyl bromide is soluble in water and miscible with several organic solvents. It decomposes upon heating, emitting toxic fumes of hydrogen bromide and bromine, and reacts with metals in the presence of water, potentially causing fire and explosion hazards.
Other Information on Methyl Bromide
1. Production Method
Typically produced by the reaction of methanol with hydrobromic acid, methyl bromide can also be generated in processes alongside tetrabromobisphenyl A.
2. Safety
Exposure to methyl bromide can harm the nervous, respiratory, liver, kidney, and digestive systems, and pose risks of genetic disorders and adverse reproductive effects. It is also toxic to aquatic life, requiring careful disposal and handling with appropriate protective gear.
3. Handling
When handling methyl bromide, use respiratory protection, gloves, eye protection, and protective clothing, and ensure the presence of safety showers and eye wash stations. In case of fire, evacuating the area is advised due to the high risk of explosion.
4. First Aid Treatment
In case of exposure, ensure the affected individual is moved to fresh air and rinsed thoroughly if skin or eye contact occurs. Due to its lack of odor at dangerous concentrations, ensure adequate ventilation when using methyl bromide.
5. Storage
Store in a cool, dry, well-ventilated area away from heat, sparks, open flames, and strong oxidizers, ensuring containers are sealed and secured.