METHYL CHLORIDE

also called chloromethane a colourless, flammable, toxic gas belonging to the family of organic halogen compounds. It is used in the manufacture of silicone polymers, tetramethyllead (an antiknock agent for gasoline), and methylcellulose (a textile-sizing agent) and as a solvent in the production of butyl rubber. It has also been used as a refrigerant, but less toxic and less flammable compounds have largely replaced it. Methyl chloride was first prepared about 1835 from methanol, sulfuric acid, and common salt. The oldest commercial process was the thermal decomposition of betaine, a waste product of the beet-sugar industry; later methods depend on the reaction of methanol with hydrogen chloride or of methane with chlorine. The compound is ordinarily stored and shipped as the liquid, which boils at -24 C (-11 F) at atmospheric pressure.