HS CODE: 2831.10

CAS No.: 7775-14-6    EINECS NO.: 231-890-0

 

PHYSICAL STATE

White crystalline powder with weak sulforous odor

 

Sodium Hydrosulfite is a white powder. Commercial sodium hydrosulfite contains 85% - 90% sodium dithionite w/w. It is readily soluble in water and shows powerful reducing action in aqueous solutions.

Sodium hydrosulfite is used as a reducing agent in dying application. It undergoes reduction reaction with water-insoluble vat dye and sulfur dye to form water-soluble alkali metal salt of the dye (leuco form ) so that they have affinity for the textile fiber. The reductive decomposition of the excessive dye by sodium hydrosulfite improve the colour fastness. Sodium hydrosulfite's reduction reaction removes residual oxide and wrong pigments. Sodium hydrosulfite is a reductive bleaching agent. It reduces carbonyl and alcohol groups, which function as colorants of the substances. It is used in bleaching mechanical paper pulp, cotton, wool and kaolin clay. Additional applications include water treatment, leather processing, food processing, gas purification, cleaning, printing and stripping. In addition to a reducing agent function, sodium hydrosulfite functions as a sulfonating agent and sodium ion source in a variety of chemical reactions.

 

OTHER INFORMATION

Hazard Symbols: XN, Risk Phrases: 22-31-7, Safety Phrases: 7/8-26-28A-43