Formaldehyde (Molecule of the Month for July 1998)
Formaldehyde was discovered by Wilhelm Von Hofmann with Alexander Butlerov in 1867. Despite this it was not isolated and purified until 1892. This was achieved by Friedrich Von Stradonitz, who also introduced the concept of chemical bonds. Formaldehyde is also called methanal and is formed by oxidising methanol. Formaldehyde is rarely found in its original state because it has a short half-life in air. This is mainly caused by its decomposition in light to form a toxic substance. In water it is very unstable and it easily dissolves which is the form that it takes when it is transported commercially. Its melting point is -92° C and Its boiling point is ~ 20° C.
Its chemical formula is CH2O. It has an odour that is pungent and suffocating, which is distinct. It is used for many purposes but its most well known is for preservation. It preserves tissue from living organisms and is used for sample preservation in many laboratories. Damien Hirst now uses it for art preservation in his work; his famous contemporary art includes dead sheep, cows, sharks, rats and maggots. Formaldehyde is also used in the formation of resins like Bakelite, a condensation of formaldehyde and phenol. Other uses include embalming solutions, explosives, photography, fertilisers and wart remedies.
Formaldehyde is highly toxic, and the major toxic exposure occurs at the eye, the nose and the throat. Small amounts of formaldehyde can cause harm because it is so toxic. Exposure leads to eye nose and throat irritation, which can lead to chest pains wheezing and bronchitis. Skin irritation can occur if there is liquid contact with the skin and allergic reactions may occur. If ingested the formaldehyde corrodes the alimentary canal and the intestines. Formaldehyde is also a suspected carcinogen. This means that, although not yet confirmed, there is a strong chance that this can cause, or encourage, the growth of a cancer. This is being investigated with other substances to allow a chance to stop public exposure to these carcinogens.
Formal Chemical Name (IUPAC)
Update by Karl Harrison
(Molecule of the Month for July 1998 )