Sodium Metabisulfite also called Sodium Pyrosulfite or disodium, sodium metabisulphite,SMBS, is an inorganic compound composed of sodium, sulfur and oxygen. Its chemical formula is Na2S2O5. It typically comes in a white or yellowish-white crystalline powder. It easily dissolves in water. The substance is sometimes referred to as disodium (metabisulphite). It is used as a disinfectant,antioxidant and preservative agentï¼?and widely used in mineral processing. we are SMBS manufacturer from China,best quality ,best price,contact me now,