Additives involved in idiosyncratic food intolerance reactions. Sodium and potassium bisulfite and metabisulfite are used in food products to prevent spoilage by microorganisms as well as oxidative discoloration. They are added, among others, to salads, wine, dehydrated fruits, potatoes, seafood, baked goods, and tea mixtures. Symptoms that may occur in sulfite-intolerant persons are airway constriction, flushing, itching, urticaria, angioedema, nausea, and in extreme cases, hypotension.
A particular form of preservative that triggers allergic responses in certain individuals.