Henan Hongye Chemical Company Ltd. is the leading professional manufacturer and supplier of Thiourea dioxide and pulp bleaching agent FAS in the world. We can produce 50000MT Thiourea Dioxide(Formamidine sulfinic acid) and bleaching agent FAS per year. Thiourea Dioxide (TDO or TUD) is also named as Formamidine Sulfinic Acid. Its appearance is white crystal powder. Thiourea Dioxide is a stable compound with no strong reducing and oxidizing ability, and its dissolvability is 26.7g/l (20 oC),while its PH is 5.0 in saturated solution. Thiourea Dioxide (TDO) appears terrific stable even in 20oC -30oC solution, but when it is under heat or catalysesing by alkali, it decomposes gradually to produce sulfoxylic acid through formamidine sulfinic acid to exhibit a reducing action. Thiourea Dioxide (TDO) is a new kind of reducing agent that used as exchange of sodium hydrosulfite. It is widely used in textile and paper making industry. This product is also used in leather processing industry, paper, pulp and board industry, photographic industry, bleaching and reducing agents. This product is also a component of decolorisation agents. In macromolecule material industry, it is used as catalysis agent and stabilizer of resinic producing, and it is also used in organic synthesization of sensitizing material, and medicine, medical, spicery materials in fine chemicals, and also can be applied in the recycling and separating of heavy metals. Other Name: Formamidine sulfinic acid, Amino imino methanesulfinic acid Formula: CH4N2SO2 short name:TDO,THU CAS No.: 1758-73-2 or 4189-44-0 UN No.: 3341 Dangerous Goods Class: 4.2 1. Specification: Purity: 99.%Min Thiourea: 0.10%Max Moisture:0.05%Max Iron(Fe):10ppm Max Sulphate: 0.17%Max 2. Packing: a.500kg and 1000kg container bags. b.25kg or 50kg plastic bags. c. 100kg or 160kg drums. d. 25kg kraft paper compound plastic bags. e.50kg fiber drums.