It is used as a preservative and antioxidant in food and is also known as E223. [2]

It may cause allergic reactions in those who are sensitive to sulfites, including respiratory reactions in asthmatics, anaphylaxis and other allergic reactions in sensitive individuals. [3][4]

Sodium metabisulfite and potassium metabisulfite are the primary ingredients in Campden tablets, used for wine and beer making. [5]

The acceptable daily intake is up to 0.7 mg per kg of body weight. [6] Sodium metabisulfite has no side effects; It is oxidised in the liver to harmless sulfate and excreted in urine.