Sodium Hydrosulphite

Sodium Hydrosulphite

Sodium hydrosulfite (also known as sodium dithionite) is a white crystalline powder with a sulfurous odor. Although it is stable in dry air, it decomposes in hot water and in acid solutions.

Usage of Sodium Hydrosulphite:

Industry, Laboratory, Photography and other.

Being water-soluble, sodium dithionite is used as a reducing agent in some industrial dyeing processes. In the case of sulfur dyes and vat dyes, an otherwise water-insoluble dye can be reduced into a water-soluble alkali metal salt (e.g. indigo dye).

sodium dithionite is often used in soil chemistry experiments to determine the amount of iron that is not incorporated in primary silicate minerals. Hence, iron extracted by sodium dithionite is also referred to as “free iron.”

Chemical formula:


Other names:

D-Ox, Hydrolin, Reductone; Sodium dithionite, Sodium sulfoxylate, Sulfoxylate; Vatrolite, Virtex L;
Hydrosulfit, Prayon; Blankit, Albite A, Konite; Zepar, Burmol, Arostit


White to grayish crystalline powder, light-lemon colored flakes


2.38 g/cm3 (anhydrous)
1.58 g/cm3 (dihydrate)