Sulfur dioxide - SO2

Sulfur dioxide is a colourless, poisonous gas with pungent smell and sour taste. Large amounts of the gas are formed in nature by volcanic activity and oxidation of organic sulfides.

The most common use of sulfur dioxide is in the production of sulfuric acid (H2SO4), but it is also used as a bleaching agent in the pulp and paper industry.

The major hazard of sulfur dioxide is inhalation.


  • Molecular weight:

    64.064 g/mol

  • Gaseous phase:

    Gas density (1.013 bar at boiling point): 3.0571 kg/m3
    Gas density (1.013 bar and 15 °C (59 °F)): 2.7633 kg/m3

  • Liquid phase:

    Boiling point: -10.02 °C
    Liquid density (1.013 bar at boiling point): 1461.1 kg/m3

  • Critical point:

    Critical temperature: 157.49 °C
    Critical pressure: 78.84 bar
    Critical density: 525 kg/m3