Sodium Metabisulphite (Na₂S₂O₅)

Sodium Metabisulphite (Na₂S₂O₅), also known as disodium disulfite, is a white crystalline or powdery substance with a slight sulfur odor. It is a widely used food preservative, antioxidant, and disinfectant, known by its E-number, E223. Sodium Metabisulphite is highly soluble in water and releases sulfur dioxide (SO₂), which gives it its preservative properties.

Applications:

1. Food Industry:
   • Used as a preservative and antioxidant (E223) in food products like dried fruits, potato products, and beverages to prevent spoilage and browning.
   • Used in winemaking to inhibit the growth of wild yeast and bacteria during fermentation.
2. Chemical and Pharmaceutical Industry:
   • Employed as a reducing agent in chemical reactions and in water treatment.
   • Used in the production of some pharmaceuticals, where it acts as an antioxidant or stabilizer.
3. Textile and Paper Industry:
   • Used in bleaching processes and in the manufacture of pulp and paper to prevent oxidation.
4. Water Treatment:
   • Added to water as a disinfectant and to remove excess chlorine from water supplies and swimming pools.
5. Photography:
   • Utilized in photographic processing as a developer and fixer solution to prevent oxidation.

Handling and Safety:

• Personal Protection: Use appropriate protective equipment (gloves, goggles, and protective clothing) when handling to avoid skin and eye contact.
• Inhalation: Avoid inhalation of dust, which can cause respiratory irritation. Work in a well-ventilated area, or use a respirator if necessary.
• Spills: Sweep up any spilled material, avoiding the generation of dust, and dispose of according to local environmental regulations.
• First Aid Measures:
  • Inhalation: Move to fresh air immediately. If symptoms persist, seek medical attention.
  • Skin/Eye Contact: Rinse affected area with plenty of water. Seek medical advice if irritation occurs.
  • Ingestion: Do not induce vomiting. Rinse mouth and drink water. Seek medical help immediately.

Storage:

• Store in a cool, dry, and well-ventilated area away from moisture, acids, and heat sources.
• Keep the container tightly closed to prevent the absorption of moisture and the release of sulfur dioxide gas.
• Avoid storing near incompatible materials, such as strong oxidizing agents, as it can result in hazardous reactions.