Sulphites

Sulphites are compounds that occur natually in wine and are commonly used in foods as perservatives, to arrest fermentation or prevent spoilage and oxidation. They come in various forms including sulfur dioxide, potassium bisulfite and sodium bisulfite (or metabisulfite). Some people are allergic to sulphites. Asthmatics and those allergic to aspirin are more likely to react to sulphites.