Sodium Sulphite

Sodium Sulphite is a soluble sodium salt of Sulfurous Acid (sulphite). It is primarily used in the pulp and paper industry and as a food preservative (E221). A pale yellow, water-soluble solid, it is used commercially as an antioxidant and preservative.


Molar Weight126.04 g/mol
Melting Point33.4°C
Density2.63 g/cc
FormsCrystals, White, Yellow, Pale, Crystalline

Uses and Applications

Key applications

  • Wastewater treatment
  • Food additive
  • Leather processing
  • Plating
  • Water treatment
  • Pulp and paper
  • Textile handling
  • Rubber


  • Pulp & Paper
  • Cosmetics
  • Water Treatment
  • Chemical Processing

Synonyms: Natriumsulfit, E 221, Na2SO3, Sodium Sulfite, Sodium Sulphite

Chemical Formula: Na2SO3

CAS Number: 7757-83-7