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About natural gas
Last updated on 15. September 2017
Natural gas contains 89 per cent methane CH4. Other components are small quantities of ethane, propane, butane, pentane and hexane and traces of water, sulphur, nitrogen and carbon dioxide.
Gas quality
The requirements applying to natural gas supplied to the Danish market are set by the Danish Safety Technology Authority and can be found in the Danish Gas Regulations, Section A, App. 1A. Natural gas received by, transported through and redelivered to the Danish natural gas system pursuant to a transport agreement must always comply with the Danish Gas Regulations and the quality specifications stipulated in Rules for Gas Transport.
Detailed information on the composition of natural gas and its burning behavior can be found under the menu item system operation at
Natural gas is non-toxic and, being lighter than air, usually ascends. However, leaking natural gas is ignitable and can cause fire. Natural gas is only inflammable in a specific mixing ratio with air.
Experience shows that such accidents are very infrequent, but in the event of an accident, a series of contingency plans prepared by Gas Storage Denmark A/S in cooperation with the police and the fire brigade will be implemented. The plans are tested at regular intervals.
For natural gas to burn, it must be mixed with air at a percentage of 5 – 15. If the percentage of gas in air is higher than 15, the gas will not burn – in daily terms, the mixture of gas and air is too rich.
The safety system at the gas storage facility at Lille Torup shuts down the moment it detects a gas leak corresponding to 25 per cent of the volume of 5 per cent gas/95 per cent air that makes leaks inflammable. The caverns contain 100 per cent gas so there is no danger of any gas being ignited far below ground level.