Sulphur dioxide 2010 - Winter limit value for the protection of ecosystems

In the air quality directive (2008/EC/50), the EU has set two limit values for sulphur dioxide (SO2) for the protection of vegetation within the zones designated by member states: the SO2 annual mean value may not exceed 20 micrograms per cubic metre (µg/m3) and the SO2 mean value for the winter period (1 October to 31 March) may not exceed 20 micrograms per cubic metre (µg/m3).