Phenol (Molecule of the Month for July 1998)
Phenol is found naturally in decaying dead organic matter like rotting vegetables and in coal. It was first isolated in 1834 from coal tar and this remained the main source of phenol until the First World War. The first synthetic method was then devised and all of the phenol today is man made. The prolonged sulphonation of benzene produces a benzene sulphonic acid, which, when fused with caustic alkalis, form a phenol.
Phenol’s chemical formula is C6H5OH and as a solid it is a white crystalline compound
Its melting point is 41° C and its boiling point is182° C. Phenol has a sweet odour that is detectable at 0.06 PPM, which enables it to be used in an air freshener. The largest use for phenol is in low cost, versatile resins. They are mainly thermoset resins used in plywood adhesion, construction and the motorcar industry.
Another use for phenol includes an intermediate stage in the process of producing caprolactam, which is used in nylon and many other man-made fibres. Phenol is also a powerful disinfectant and bacteria killer. This is ideal for not only an air freshener but also other products like medicinal ointments and lotions. However the chemical is highly corrosive and moderately toxic. It effects humans by burning the skin and other tissue that it comes into contact with. This gives severe skin burning and if inhaled serious internal corrosion. The skin burning is not initially felt because the phenol has a local anaesthetic effect. It can affect the central nervous system, which will at first lead to sweating, weakness, dizziness and twitching but with prolonged exposure leads to nausea, vomiting and coma. If ingested even a small dose can lead to be fatal in humans and therefore care must be taken at all times using phenol-containing products.
Formal Chemical Name (IUPAC)
Update by Karl Harrison
(Molecule of the Month for July 1998 )