Sulphur dioxide

Sulphur dioxide is a colourless, water soluble gas with a pungent smell. It is produced from combustion of fossil fuels, for example coal and oil.

Human health and the environment are negatively influenced by high sulphur dioxide concentrations. Oxidation processes lead to "acid rain", which causes long-term damage to ecosystems. In the 1970's the region between Dresden, Prague and Krakow ("sulphur triangle") was particularly affected by acid rain. A large number of coal-burning power plants concentrated in a small area led to dramatic air pollution. Furthermore, "acid rain" also damages buildings and materials. In the atmosphere, sulphur dioxide reacts to sulphate particles, which contribute to the particulate matter load (PM10).

Limit values

Limit values for sulphur dioxide for protection of human health were put into force on 1 January 2005. The 1 hour limit value was set at 350 µg/m3 and may not to be exceeded more than 24 times per year. The daily limit value of 125 µg/m3 may not to be exceeded more than 3 times per calendar year.