Sodium Metabisulphite: key Specifications & Special Features : Sodium Metabisul fiteSodium BisulfiteAsk for PriceSodium metabisulfite, also called Sodium Pyrosulfite or Disodium, 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 agent."