Product name : Sodium Metabisulphite Other Names: Sodium Metabisufite;Sodium Pyrosulfite; SMBS; Disodium Metabisulfite; Disodium Pyrosulphite;Fertisilo;Metabisulfitede Sodium; Sodium Metabisulfite (Na2S2O5);Sodium Pyrosulfite(Na2S2O5); Sodium Dissulfite;Sodium Disulphite; Sodium Pyrosulphite. Appearance: white or yellow crystal powder or small crystal ;Storage for a long time color gradient yellow. PH: 4.0 to 4.6 Category: Antioxidants. Molecular formula : Na2S2O5 The molecular weight : 190.10 CAS : 7681-57-4 EINECS : 231-673-0 Melting point: 150℃ (decomposition) Relative density (water =1) : 1.48