CH3Cl

CH3Cl, commonly known as methyl chloride, is the simplest chlorinated hydrocarbon. It consists of a methyl group bonded to a chlorine atom (CH3Cl). At room temperature it is a colorless gas with a faint, sweet odor. It is soluble in many organic solvents and is denser than air. It is flammable and handling requires appropriate ventilation and precautions to prevent inhalation exposure.

Industrial production of methyl chloride is primarily by free-radical chlorination of methane: CH4 + Cl2 → CH3Cl + HCl. The process also forms higher chlorinated methanes such as CH2Cl2, CHCl3, and CCl4 if not carefully controlled, so purification and separation are typically required. In addition, CH3Cl can be obtained as a byproduct in certain chlorine-based processes. It is usually stored as a compressed gas or as a low-boiling liquid.

As a chemical intermediate, CH3Cl is used to synthesize a range of chloromethyl derivatives and other organochlorines. Historically it served as a refrigerant (often referred to as R-40) and as a solvent in some industrial applications, but its use has declined due to safety concerns and regulatory restrictions.

Environmental and safety considerations include its role as a source of reactive chlorine in the atmosphere, where it can contribute to ozone depletion and related environmental concerns. Methyl chloride is toxic by inhalation and can affect the nervous system; it is also flammable, so appropriate engineering controls and protective equipment are important in any handling or industrial setting.