Products
Sulfites are added to pharmaceuticals, foods and personal care products as excipients and additives. They can also be naturally present in foods. Even the Romans used sulfur dioxide as a preservative for wine.
Structure and properties
Sulfites are the salts of sulfurous acid, which is extremely unstable and undetectable in water (H2SO3). Example sodium sulfite (Na2+SO32-): The hydrogen sulfites, which are also called bisulfites, contain the anion HSO3– −. Metabisulfites have two sulfur atoms bonded together.
Representative
Sulfites and sulfur dioxide permitted as additives:
- Sulfur dioxide (SO2, E 220)
- Sodium sulfite (Na2SO3, E 221)
- Sodium hydrogen sulfite (NaHSO3, E 222)
- Sodium metabisulfite (Na2S2O5, E 223)
- Potassium metabisulfite (K2S2O5, E 224)
- Calcium sulfite (CaSO3, E 226)
- Calcium hydrogen sulfite (Ca(HSO3)2, E 227)
- Potassium hydrogen sulfite (KHSO3, E 228)
Effects
Sulfites have antioxidant, preservative and antimicrobial properties.
Fields of application
As preservatives and antioxidants for pharmaceuticals, foods, semi-luxury foods and personal care products. Foods and stimulants containing sulfites include wine, beer, dried fruits, sausages, fish and canned tomatoes (selection).
Contraindications
- Hypersensitivity
For complete precautions, see the drug label.
Adverse effects
Possible adverse effects include allergic reactions and an intolerance reaction. These include anaphylactoid reactions, skin rashes, edema (swelling), low blood pressure, nausea, vomiting abdominal pain, diarrhea, breathing difficulties, cough, and bronchoconstriction. The adverse effects are potentially life-threatening.
