Product Name: sodium pyrosulfite / sodium metabisulphite Molecular Formula: Na2S2O5 CAS NO.:7681-57-4 Appearance: White or yellow crystalline powder or small crystallization Application: In industry, it is used for organic synthesis, printing and dyeing, printing, leather, pharmaceutical and other departments; In the processing of food, it is used as bleaching agent , antiseptic and osteoporosis agent,