... Na2S2O5 Used in Mining, Food, Leather Origin: Hunan, Tianjin Sodium Metabisulphite 98.0%Min (SO2:65%Min) (Changsha Yonta) ... Weight.190.12ToxicityLD50:178 mg/kg (rabbit vein)Synonymssodium pyrosulfite, sodium metabisulfite- Physical And Chemical PropertiesPhysical State(Appearance)White ... little in ethanol. Decomposed in humid, oxygenized into sodium sulfate by exposed in air, sulpher dioxide will be ...