... NO: 7681-57-4 white or light yellow crystalline powder sodium metabisulphite tech grade 97% is white crystalMolecular formula Na2S2O5Molecular weight ... the material of fine chemicals, or used asdeveloper; In food industry, It can be used as bleaching agent, loosening agent, antisepsisbactericide ... , with covering matter, avoid raining.Netwt. 25kg, 50kg, 1000kg/bag. Sodium Metabisulfite