The British Pharmacopoeia preparation, formaldehyde solution, contains 34–38 per cent formaldehyde in water. It is a powerful antiseptic, and also has the power to harden the tissues. The vapour is very irritating to the eyes and nose.
Uses For disinfection it is largely used in the form of a spray; it can also be vaporised by heat. One of its advantages is that it does not damage metals or fabrics. In 3 per cent solution in water it is used for the treatment of warts on the palms of the hands and the soles of the feet.