Sodium sulfite
General Product Information
| Article | Sodium sulfite |
| Synoniemen | E221, Hypo clear |
| CAS No. | 7757-83-7 |
| EEG No. | – |
| EINECS No. | 231-821-4 |
| IMO | – |
| Tariff Code | 28321000 |
| UN No. | – |
| VLG/ADR | – |
Description
Sodium sulfite is an inorganic salt. It consists of sodium and sulfite ions and occurs as a white, crystalline powder that is highly soluble in water. It is widely used in industrial and commercial applications because of its reductive properties and stabilizing effect.
Characteristics
- Odor: –
- Hygroscopic: Yes, light.
- Color: White.
- Grade: Food.
- Solubility: Highly soluble in water.
- Taste: –
- Shape: Crystalline powder.
Physical & Chemical Properties
| Chemical Structure | Na2SO3 |
| Molar Weight | 126.04 g/mol |
| Melting Point | – |
| Boiling Point | – |
| Density | – |
| Refractive Index | – |
| pH | Approx. 9.0 (on 1% solution) |
Interessing Links
- Codex Alimentarius (FAO/WHO) – Guidelines and standards for food additives and ingredients.
- European Chemicals Agency (ECHA) – For chemical information and regulations.
- European Food Information Council (EFIC)
- European Food Safety Authority (EFSA) – Information on the safety and uses of food additives and ingredients.
- PubChem – Sodium Sulfite – Chemical information by the National Library of Medicine of the National Center for Biotechnology Information (NIH-NCBI).
- Wikipedia – Sodium sulfite
Applications
Sodium sulfite is applied in various ways, for instance:
1. Food Industry
Sodium sulfite is used as a preservative and antioxidant under the food additive E221. It prevents oxidation and enzymatic discoloration, especially in dried fruits, vegetables, wine, beer and shellfish.
2. Water Treatment
It is used to remove residual free chlorine or oxygen from boiler water or process water. This prevents corrosion in pipes and systems.
3. Textile Industry
Serves as a bleach and neutralizes residual chlorine after bleaching fabrics.
4. Textile & Pulp Industry
Used in the sulfite process to produce wood pulp.
5. Photography
In photographic development processes, sodium sulfite is used as a preservative to inhibit oxidation of development chemicals.
6. Chemical Industry
Used as an intermediate or reductor at various synthesis processes.