white or light yellow crystal powder, a strong smell of sulfur dioxide,relative density is 1.4, easy to dissolve in water and glycerin, water solution. It has acidity,and its solubility will become large while raising the temperature and is less to dissolve in ethanol.

(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 
The hide profession employ to do to molt dose and pliable dose and wearproof dose; sewage treatment, and so on .

(3) Pharmaceutical Grade: In chemical synthesis in the production of acrylic fibre, vitamin K, vitamin A, pharmaceutical intermediates, etc.

(4) Photo Grade: The sensitize industry is served as the developing agent reductant and the protection of fixing bath dose.