Sodium metabisulfite

It is used as a preservative, bleaching agent, and loosening agent in food processing. Industrially, sodium metabisulfite is used in dyeing, organic synthesis, printing, leather making, pharmaceutical and other departments; sodium metabisulfite is used in the chemical and pharmaceutical industries to produce hydrosulfite, sulfadimethoxine, analgin, caprolactam, etc., as well as the purification of chloroform, phenylpropyl sulfone and benzene formaldehyde. It is used as an ingredient of fixer in the photographic industry. It is used in the spice industry to produce vanillin. It is used as a preservative in the brewing industry, a rubber coagulant, and a dechlorinating agent after bleaching cotton cloth. It is used as an organic intermediate, dye, and a reducing agent in leather making. It is used in the electroplating industry, wastewater treatment in oil fields, and as a mineral processing agent in mines.