What does dichloromethane mean?
Dichloromethane is a colourless, volatile liquid belonging to the family of chlorinated hydrocarbons, with the chemical formula CH₂Cl₂. It carries two chlorine atoms attached to a single carbon atom, giving it a sweetish odour and an exceptional ability to dissolve oils, fats, waxes, and many other organic materials. This makes it one of the most widely used industrial and laboratory solvents: it appears in paint strippers, metal degreasers, adhesives, and countless chemical extraction procedures, including the removal of caffeine from coffee beans. In British and international scientific usage it is called dichloromethane, while American industry often uses its older common name, methylene chloride, abbreviated DCM. The word belongs to formal, technical registers and rarely surfaces outside chemistry, manufacturing, and safety regulation. Its usefulness comes with caution: exposure to its fumes poses health risks, so the term frequently appears in occupational-safety guidance and environmental discussion.
nounA volatile, colourless liquid chlorinated hydrocarbon (CH₂Cl₂) with a sweetish odour, widely used as a solvent, paint stripper, and degreaser. It is also known by the common name methylene chloride.
- A colourless, volatile chlorinated hydrocarbon liquid (CH₂Cl₂), used chiefly as a solvent in paint removers, degreasers, and laboratory extractions, and historically in decaffeination of coffee.
"The chemists extracted the compound from the plant material using dichloromethane as the solvent."
"The laboratory used dichloromethane to extract the organic compounds from the aqueous layer."
"Workers removing old paint were advised to ventilate the area carefully because dichloromethane vapours are hazardous when inhaled."
As a mass noun referring to the substance, dichloromethane is normally uncountable. A plural is rare and appears only when referring to different samples or isotopic variants in technical writing.
"The study compared several dichloromethanes recovered from different sources."
Dichloromethane can dissolve caffeine out of coffee beans — which is why it plays a starring role in how decaf gets made.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of dichloromethane
The word dichloromethane is built from Greek-derived scientific elements: the prefix di- ('two'), chloro- (from Greek chlōros, 'pale green', coined for chlorine by Humphry Davy's circle in the early nineteenth century), methane (from Greek methy, 'wine', via methyl), and the chemical suffix -ane denoting a saturated hydrocarbon. It arose as part of the systematic nomenclature developed for organic chemistry, naming the compound as a methane molecule bearing two chlorine atoms. Its older synonym methylene chloride reflects an earlier naming tradition built on 'methylene'.
How dichloromethane is actually used
A technical term used mainly in chemistry, industry, and regulatory contexts. In American usage 'methylene chloride' is more common; 'dichloromethane' is the preferred IUPAC name. Because it is hazardous if inhaled or handled improperly, the word often appears alongside safety warnings.
Easily confused with dichloromethane
Trichloromethane (CHCl₃) has three chlorine atoms and is better known as chloroform, whereas dichloromethane (CH₂Cl₂) has two and is a distinct solvent with different properties.