Usage -

1.Sodium thiosulfate is used predominantly in dyeing. It converts some dyes to their soluble colorless "leuco" forms. It is also used to bleach cotton, silk and so on.

2.In photography, sodium thiosulfate (Sodium Subsulfite)is known as a fixer, sometimes still called the original chemical name hyposulphite of soda. It functions to dissolve silver halides, , components of photographic emulsions. It is used for both film and photographic paper processing.

3. sodium hyposulfite is used to dechlorinate tap water including lowering chlorine levels for use in aquariums, swimming pools, and spas and within water treatment plants to treat settled backwash water prior to release into rivers. Reduction reaction is analogous to the iodine reduction reaction.