Sodium Sulphite
Na₂SO₃ | CAS: 7757-83-7 | HS: 28321000
Product Description
Sodium Sulphite is a powerful, fast-acting reducing agent and oxygen scavenger — the standard chemical for deoxygenation of boiler feedwater, removal of residual chlorine from water treatment streams, and as a food preservative and antioxidant (E221). In photography, it was a key component of developing and fixing bath formulations. In textiles and paper, it is applied in bleaching processes as a reducing and anti-chlorine agent. MITCHEM supplies technical and food grades with appropriate safety and regulatory documentation.
Applications by Industry
Dosed into boiler feedwater to scavenge dissolved oxygen that causes pitting corrosion of boiler tubes and steam system metalwork — a standard oxygen scavenger for low- and medium-pressure boilers.
Reduces residual chlorine to chloride in drinking water, wastewater, and industrial process water streams where chlorine removal is required before discharge or reuse.
Functions as an antioxidant and antimicrobial preservative in dried fruits, wine, and food products — inhibits browning (PPO enzyme inhibition) and suppresses spoilage yeasts and moulds.
Applied after chlorine bleaching to neutralise excess chlorine and prevent textile and paper fibre degradation (antichlor step in bleaching sequences).