The information ‘Contains sulphites’ has been compulsory on all labels since 2005 for wines whose sulphur content is more than 10 mg/l, owing to its allergenic character. Sulphur is a stabiliser with antioxidant and antiseptic properties, and has been used in winemaking since the 18th century. It is impossible to make a wine that is completely free of sulphur as small quantities are produced naturally during fermentation.