sulphur dioxide

Preservative used in gaseous form or as salts (sulphites) for fruit drinks, wine, comminuted meat, and as a processing aid to control physical properties of flour; also prevents enzymic and non-enzymic browning. Protects vitamin C but destroys vitamin B₁. Prepared by ancient Egyptians and Romans by burning sulphur and used to disinfect wine.

A common air pollutant that irritates the upper airway. Levels above 1.0 ppm cause discomfort and are detrimental to athletic performance.