Thiourea Dioxide (or amino(imino)methanesulfinic acid) is a white coloured organic powder having the formula CH4N2O2S. It is a stable compound which easily dissolves in water, and decomposes to produce sulfoxylic acid by the application of heat in the presence of an alkali. It is most widely used in the textile industry as a reducing agent.
Thiourea Dioxide is normally made from the oxidation of Thiourea using Hydrogen Peroxide. This is done by maintaining the pH of the raw material mixture within 3 to 5 and the temperature below 10 degrees Celsius.
Thiourea Dioxide is also used as a replacement for NaClO and Sodium Hydrosulfide in mechanical paper and post-bleaching applications.
Due to its property of being able to form formamidine sulphinic acid under alkaline conditions, it is used as a reducing agent in various industries such as leather, paper, textile, pulp and board, bleaching, and photography industries.