Sodium Hydrosulfite(sodium formate method)

Basic Information

Other Names: SHS; Sodium dithionite; Sodium hypodisulfite                   

Molecular Formula: Na2S2O4    

Molecular Weight: 174.11

CAS NO.: 7775-14-6

EINECS NO.: 231-890-0

UN NO.: 1384

H.S. CODE NO.: 2831.1010

Standard: HG/T2520-93

Purity: 85% min., 88% min. & 90% min.

Physical Properties

1.Appearence: Rhombic white crystalline

2.Specific Gravity: 2.36(real),1.2(bulk)

3.Autogenous Ignition Temperature: 250 ℃

4.Temperature of Explosion: 190 ℃

5.Stability: 21.8% at 20 ℃,readily soluble in water,very slightly soluble in alcohol Chemical properties

Chemical Properties

Showing a powerful reduction behaviour, it will be oxidized into sodium bisufite andsodium bisulfate on exposure to air. To contact water, it decomposes, releases SO2 and a great quality of heat are set free. Therefore, it is easy to inflame on contacting water, it is unstable in water solution. With the hydrolization occurring, the nascent hydrogen is generated. Generally, it is more stable in alkaline medium than neutral medium.

To be moistened it decomposes, heats,so inflammation is easy to being cause. On heating beyond 75℃,it decomposes intensely,it inflames spontaneously at 250℃. A certain amount of stabilizing agent is added to the finished product,because of its unsteadiness.

Technical Specifications

Names of IndexIndex
AppearanceWhite Crystalline Powder
Stacking Density1.2-1.3 GM/M1
Water Insoluble≤0.2%≤0.4%≤0.4%

Packaging Types

          25kg steel drum; 50kg steel drums or as per customers' requirement


As a reductant it is widely used in printing and dyeing industry,as dyeing assintant for cotton textile,as a bleaching agent for silk. Woollen fabrics etc. It is also used to bleach sugar juice,maltose etc. in food industry. As raw material in pharma-ceutical industry as well as synthetic dyestuff. In adition,it is applied in copperplate printing process and also as an analytical reagent.

Transport Information

1.IMDG: Class 4.2

2.Packaging group: II

3.Storage: As dangerous goods,it should be kept in cool,dark and dry place,protected against moisture,avoided exposure to direct sunshine,don't to let it be rained on. Be sure not to store it together with oxidant and acid, no presence of acidic vapour in storeroom is allowed. Storage life is one year.