Sodium Hydrogen Sulphite
SBS, Sodium Bisulfite, Sulfurous Acid Monosodium Salt.
- CAS
- 7631-90-5
- EC
- 231-548-0
- Sectors
- Water & Wastewater Treatment, Textiles, Leather & Paper
Sodium Hydrogen Sulphite (CAS 7631-90-5) is an inorganic salt supplied as a white powder or a 38-40% aqueous solution, and it works as a reducing agent that neutralizes residual chlorine, removes dissolved oxygen, and supports bleaching and dye removal in textile and paper processing. It is a powerful reducing agent used to neutralize residual chlorine and remove dissolved oxygen in high-pressure industrial systems.
In industrial processing, it serves as a critical dechlorinating agent, protecting sensitive downstream membranes and preventing oxidative damage. Its reductive properties are also leveraged in the textile industry for bleaching and the removal of excess dyes after processing.
The chemical exhibits consistent purity and stability, making it a reliable additive for fermentation processes and food-grade preservation when specified. Its ability to act as a bisulfite adduct former is vital for the purification and isolation of aldehydes and ketones in specialty chemical manufacturing.
Typical Properties
| Molecular formula | H2O3S.Na |
|---|---|
| Molecular weight | 104.06 g/mol |
| Form | Powder/Solid |
| Color | White |
| Odor | Slight odor of sulfur dioxide |
| Melting point | 150 °C |
| Density | 1.48 g/cm³ |
| Water solubility | 300 g/L |
| pH | 4.5 (20°C in H2O) |
| GHS signal word | Danger · Corrosive, Irritant / harmful, Health hazard |
| HS code | 28323010 |
| Grades available | Technical Grade |
Typical literature values for identification; lot-specific results are stated on the certificate of analysis (COA) and the safety data sheet (SDS) that accompany every delivery.
Sodium Hydrogen Sulphite
Applications
- Water Treatment: Rapidly neutralizes residual chlorine in municipal water and industrial effluent before discharge to protect aquatic life.
- Pulp and Paper: Utilized in the bleaching process to achieve desired brightness and in the removal of lignins during paper production.
- Textile Industry: Acts as an antichlor after bleaching with chlorine-based agents and as a reducing agent in vat dyeing.
Safety & Risks
Classified as Acute Toxicity (Oral) and Skin/Eye Irritant. Releases Sulfur Dioxide Gas if mixed with acids; use in Well-Ventilated Areas with appropriate Respirators.
Packaging
25 kg Bags (powder), 250 kg Drums, and 1250 kg IBC Tanks (liquid solution).