(1) Food Grade: Bleach agent (e.g. candies, cake, bamboo shoots, etc); Loose agent (e.g. bread, cracker etc); Antiseptic and germicide (e.g. fruit juice, tinned food, brews, the cereals food is defended storage etc); Inhibitor and freshen agent (e.g. day lily, seafood, fruit and vegetable etc).
(2) Industry Grade: Mordant of printing and dyeing; Dechlorinate of textile after bleaching; Sulphonated agent and reducer of chemical industry and pharmacy; Bleach of paper pulp, bamboo and timber bleach of Stap; Treatment agent of waste water; Rubber solidifying agent Perfume industry is served as hydro carbon perfume aldehyde.
http://www.chinafooding.com/Sodium_Metabisulfite