Formaldehyde

Formaldehyde, also known by the systematic name methanal, is a gas with a strong pungent smell, one of the aldehyde group of organic chemicals. Its chemical formula is HCHO, sometimes rendered as H₂CO. It has a boiling point of -21°C (262 K).

A 37% solution of formaldehyde in water is known as formalin; it is usually stabilised by having a small proportion of methanol mixed in as well. It is used as a disinfectant[?] and to conserve biological specimens.

Formaldehyde is also as used to produce other chemicals, for instance urea-formaldehyde[?]. In particular, it can polymerise with itself to produce one molecule of Trioxane for each three molecules of formaldehyde that come together (this can also reverse spontaneously); this makes formaldehyde have unusual gas properties under compression, heating/cooling, etc.

It is generally produced by the oxidation of methanol. If a human consumes methanol, the oxidation to formaldehyde is catalyzed by alcohol dehydrogenase in the liver. Methanol is toxic mainly because the resulting formaldehyde is toxic.

Formaldehyde is a known carcinogen.