Sodium bisulfite

Sodium bisulfite (or sodium hydrogen sulfite) is a chemical compound with the chemical formula NaHSO3. Sodium bisulfite is a food additive with E number E222. This salt of bisulfite can be prepared by bubbling sulfur dioxide in a solution of sodium carbonate in water. Sodium bisulfite in contact with chlorine bleach (aqueous solution of sodium hypochlorite) will release harmful fumes.

Uses

Sodium bisulfite is used in almost all commercial wines, to prevent oxidation and preserve flavor. In the food industry, it is used as a preservative for fruits and vegetables, and in the treatment of dried foods. It is also used in the analysis of methylation status of cytosine in DNA.

Health Effects

Ingestion of sodium bisulfite may result in gastrointestinal upset and irritation of the gastric mucosa. In severe cases, life-threatening situations may occur due to metabolic acidosis and shock. Sodium bisulfite can also cause allergic reactions, especially in those sensitive to sulfites.

Environmental Impact

Sodium bisulfite is harmful to aquatic life with long lasting effects. It is also harmful to the ozone layer.

See Also

• Sodium metabisulfite
• Sulfur dioxide
• Sodium sulfite