Formaldehyde Solution USP

Formaldehyde is a naturally occurring organic compound with the formula CH2O (H-CHO). It is the simplest of the aldehydes (R-CHO) and is also known by its systematic name methanal. The common name of this substance comes from its similarity and relation to formic acid.

Formaldehyde Solution BPFormalinFormaldehyde Solution (35 per cent), EurCH2O -- 30.03 -- CAS 50-00-0Action and use: When suitably diluted, used in the treatment of warts.

DEFINITIONContent: 34.5 per cent m/m to 38.0 per cent m/m of formaldehyde (CH2O; Mr 30.03). It contains methanol as stabiliser.

CHARACTERSAppearance: Clear, colourless liquid.Solubility: Miscible with water and with ethanol (96 per cent). It may be cloudy after storage.

IDENTIFICATIONA. Dilute 1 ml of solution S (see Tests) to 10 ml with water. To 0.05 ml of the solution add 1 ml of a 15 g/l solution of chromotropic acid sodium salt, 2 ml of water and 8 ml of sulric acid. A violet-blue or violet-red colour develops within 5 min.B. To 0.1 ml of solution S add 10 ml of water. Add 2 ml of a 10 g/l solution of nylhydrazine hydrochloride, prepared immediately before use, 1 ml of potassium ferricyanide solution and 5 ml of hydrochloric acid. An intense red colour is formed.C. Mix 0.5 ml with 2 ml of water and 2 ml of silver nitrate solution in a test-tube. Add dilute ammonia until slightly alkat on a water-bath. A grey precipitate or a silver mirror is formed.D. It complies with the limits of the assay.