Sulphur oxides (SOx)


  • include, among others, sulphur dioxide (SO2)
  • sulphur dioxide: colourless, pungent smelling gas in higher concentrations

Main sources

  • industrial and household furnaces (combustion of sulphur-containing fuels)
  • volcanic eruptions

Thresholds for the reporting requirement of facilities in accordance with Annex 2 PRTRO

(Ordinance on the Register relating to Pollutant Release and the Transfer of Waste and of Pollutants in Waste Water)

  • Air               150,000 kg/year
  • Water           -
  • Soil               -


  • irritates eyes, respiratory system and skin
  • respiratory illnesses
  • damages plants and sensitive ecosystems in multiple ways
  • damages buildings and materials
  • major precursor in the formation of acid precipitation and secondary aerosols (particulate matter)

Ambient limit values of sulphur dioxide

30 µg/m3 annual mean (arithmetic mean)
100 µg/m3 95% of the 1/2-h-means of a year of less than or equal to 100 µg/m3
100 µg/m³ 24-hour mean; may be exceeded once per year at most


  • reduction of the sulphur content in heating oil
  • conversion to natural gas

Status and changes

Sulphur dioxide emissions peaked in 1980. Since the mid-1980s, the sulphur dioxide levels have decreased by over 90% thanks to successful measurements at all NABEL monitoring stations. They are now significantly under the ambient limit values.

Further information

Last modification 16.12.2016

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