Pure product is white crystals, specific gravity 1.651(21.2°C). M.P. 73.6°C, B.P. 200°C. Soluble in water and ethanol easily, and it will be oxidized into H3PO4 in the air slowly. Be decomposed into H3PO4 and sne when be heated to the temperature 180°C.H3PO3 is a kind of diacid, its acid-stage is higher than H3PO4. Be oxidized easily and has strong hygroscope and corrosively. Usage: srous acid is mainly used in the production of stes, synthetic fibers and organ srus pesticides, etc. It is also used in producing high performance water treating agent ATMP. Package: 25kg, 500kg or 1000kg woven bag for srous acid crystal 280kg/HDPE drum, 1400kg/IBC for srous acid solution