CH3Br

CH3Br, also known as bromomethane or methyl bromide, is an organobromine compound with the formula CH3Br. It is the simplest alkyl bromide, consisting of a methyl group bonded to bromine. The molecule has a tetrahedral geometry around carbon and is a colorless, volatile compound that is a gas at room temperature, with a density greater than that of air. It readily hydrolyzes in water to methanol and hydrobromic acid and is moderately soluble in water and many organic solvents.

Preparation and production methods typically involve the reaction of methanol with hydrobromic acid or hydrogen bromide to form CH3Br and water. In industrial and agricultural settings, methyl bromide has also been generated in situ for fumigation purposes.

Uses have historically included as a broad-spectrum soil fumigant and quarantine treatment due to its effectiveness against nematodes, insects, fungus, and weed seeds. It has also been employed as a methylating agent in organic synthesis. Due to regulatory restrictions and health concerns, its use in agriculture has declined and is increasingly restricted in many regions.

Safety and regulatory status are major considerations. CH3Br is highly toxic; inhalation can cause serious health effects, including respiratory irritation and central nervous system effects. It is also an ozone-depleting substance with significant environmental impact, and its production and use are governed by international agreements. Under the Montreal Protocol, production and use have been phased out or tightly controlled, with exemptions granted only for critical uses where alternatives are not available. Researchers and industry continue to pursue safer fumigation methods and substitute methylation reagents to reduce reliance on CH3Br.