Where do sulphites occur?

Sulphites (or sulfites) are the salts and esters of sulphurous acid. In the food industry, they are often used as preservatives in dried fruits, potato products and wine. However, the latter naturally contains sulphites.

Sulphites occur in low concentrations in fermented grape juice. Sulphurous acid is produced by yeast that naturally occur in grape must during the fermentation process. Hence, it is contained in all wines at a concentration of up to 40 mg / l.

What reactions are caused by sulphites?

The human body produces about 2,500 mg of sulphur dioxide per day, which is excreted as sulphate. However, doses of 1,000 mg can cause distinct reactions. The symptoms include diarrhea, vomiting, and headaches.


Directive  2007/68/EC(changes in food labelling directive  2000/13/EC attachment IIIa) regulates the current labelling of allergens in food. The directive specifies that foods must be labelled as containing sulphur dioxide or sulphites at concentrations of more than 10 mg / kg (l) expressed as SO2.