sodium sulfite

Sodium sulfite


Chemical formula: Na2SO3

Molecular weight: 126

Appearance: white to  yellowish powder

20% solution: colorless and transparent or yellowish

Packaging: 25 kg, double-layer polyethylene bags

Chemical analysis

Technical grade Food/Photographic grade*
Purity(Max.) 90% 97%
Alkalinity (as Na2CO3) (Max.) 0.3% 0.015%
Iron (Max.) 0.005% 0.002%
Amount of Ca and Mg and other substances insoluble in ammonia (Max.) ---- 0.5%
Sodium thiosulfate (Max.) ---- 0.015%
Heavy metals (as Pb) (Max.) ---- 0.002%
Ammonia silver nitrate test ---- Passed
200 g/liter solution ---- It does not settle and is not cloudy

* This product complies with ISO 418 standard (photographic grade sodium sulfite).


It is used in various industries for the following purposes:

  • In the water purification industry to remove excess oxygen and chlorine from water and prevent corrosion, especially in steam boilers and brine purification systems (sea water evaporators).
  • In oil extraction operations in order to remove oxygen from water to prevent corrosion in oil well equipment and in drilling mud.
  • In the leather industry, as an auxiliary chemical in the leather production process (and sulfation process).
  • In the mining industry, as an auxiliary material in the flotation of some mineral materials.
  • In the chemical industry, in order to produce sodium thiosulfite, sulfonation, sulfomethylation, and reduction.
  • In the food industry, as a food preservative.
  • In the photography industry, in the formulation of proven and emerging drugs.
  • In the paper industry, in some paper production processes such as semi-chemical and chemical-thermal-mechanical processes.
  • In the textile industry, in bleaching wool, polyamid fibers and removing excess chlorine after chlorination processes.
  • In the chloralkali industry, in order to remove excess chlorine.
  • In the detergent industry, in order to produce sulfosuccinates (the basic ingredient of baby shampoo).
  • In the rubber industry, in order to stabilize the latex.
Scroll to Top