Carbon dioxide - CO2

Carbon dioxide - CO2

Carbon dioxide is a colourless gas formed of two elements, carbon and oxygen. It is produced in the combustion of coal or hydrocarbons and breathing of humans and animals. Carbon dioxide is used in the photosynthesis where plants and cyanobacteria “breathe”.

Carbon dioxide is a gas that can be used in many different applications. It is for example used in the chemical industry for controlling reactor temperatures, as well as in the food and beverage industry. CO2 is also used as an alternative to sulphuric acid for pH balance control.

The main hazards of carbon dioxide are inhalation and high pressure.


  • Molecular weight:

    44.01 g/mol.

  • Gaseous phase:

    Gas density (1.013 bar at sublimation point): 2.813 kg/m3
    Gas density (1.013 bar and 15 °C (59 °F)): 1.8714 kg/m3

  • Solid phase:

    Melting point: 56.57 °C

  • Liquid phase:

    Boiling point (sublimation): -78.45 °C
    Liquid density (at -20 °C (or -4 °F) and 19.7 bar): 1256.74 kg/m3

  • Critical point:

    Critical temperature: 30.98 °C
    Critical pressure: 73.77 bar
    Critical density: 467.6 kg/m3