At ambient temperature and atmospheric pressure Methyl Chloride is a colourless inflammable gas heavier than air and with a very weak sweetish odour. In water it is only sparingly soluble but well in organic solvents. It can be liquefied by cooling below -24 °C or by pressurizing to approx. 5 bar at 20 °C, to give a clear, colourless fluid that will vaporize fast under room conditions generating much coldness.
Two ways of making Methyl Chloride are technically in use: chlorination of methane with chlorine or reaction of methanol with hydrogen chloride. A third route is naturally occurring: Methyl Chloride is formed by biomass burning and volcano eruptions, as well as by biochemical activities by wood-rotting fungi and certain algae and seaweed in the oceans. Globally huge amounts of natural Methyl Chloride (approximately 4 million tons per year) are released by these sources into the atmosphere.
Methyl Chloride is used in the chemical and pharmaceutical industry, mainly as raw material for the production of silicones and methyl celluloses, but also for surfactants, pharmaceuticals and dye stuffs. A small portion is used as low temperature solvent for the production of butyl rubbers.