Methylene chloride is one of a group of chemicals known as chlorinated hydrocarbons. At room temperature it is a colourless, highly volatile liquid with a distinctive “sweetish” odour usually not detectable by smell below about 100 ppm. Its vapour is flammable but is not considered to be an explosive hazard under normal conditions.
Being highly volatile, Methylene chloride is easily inhaled and is also readily absorbed through the skin.
Methylene chlorine acts as a neurotoxin, having narcotic and anaesthetic effects. It is also metabolised to carbon monoxide in the body, leading to increased levels of carboxyhaemoglobin and thus reducing the oxygen carrying capacity of the blood. It is thought to have a deleterious effect on the liver (though not as much as some other chlorinated hydrocarbons) and is a suspected (Category 3) human carcinogen.
Methylene chloride is able to dissolve a wide range of organic compounds and is used as a solvent in paint strippers, degreasing agents and as an extraction agent in food processing. It is also used as a blowing agent in polyurethane foam production.