Lately, when talking about wine production , sulphur dioxide is one of the most talked about aspects, both from wine lovers and producers. Opinions are divided in two categories: people who think that it is essential to produce high quality wines and people who think that you can reach a wine high standard level with low quantities or simply not using it. But, what is Sulphur dioxide? What is it used for? Which effects does it have on our body? If you are looking for answers, do keep on reading. What is Sulphur dioxide? Sulfur dioxide, (SO2), inorganic compound, a heavy, colourless, poisonous gas. Sulphur dioxide has a pungent, irritating odour, familiar as the smell of a just-struck match. When used in recommended concentrations, it can induce asthma when inhaled or ingested by sensitive subjects, even in high dilution. What is it used for ? Sulphur dioxide is widely used in the food and drinks industries for its properties as a preservative and antioxidant and it is identified as E220. In wine production it can be used both during wine making processes and added to must during alcoholic fermentation. This compound presents various properties: Antioxidant: it protects wine from oxidation caused by air contact Antiseptic: it selects yeasts and stops bacteria development Soluble: it helps color extraction from skins In wine, a part of sulphur dioxide called free SO2 (gaseous) is also found in air or in inorganic combinations What effects does sulphur dioxide have on our body and environment? Despite of its antioxidant and antiseptic properties, SO2 remains the worst sulphur based air pollutant. The largest sources of SO2 emissions are from fossil fuel combustion at power plants or industrial facilities. Smaller sources of SO2 emissions include: industrial processes such as extracting metal from ore; natural sources such as volcanoes; locomotives, ships and other vehicles and heavy equipment that burn fuel with a high sulfur content. Short-term exposures to SO2 can harm the human respiratory system and make breathing difficult. People with asthma, particularly children, are sensitive to these effects of SO2. Small particles may penetrate deeply into the lungs and in sufficient quantity can contribute to health problems. In wine it can cause heavy headaches, gastric irritation and it can disturb, combined with ethanol, our nervous system