Natural gas is lighter than air, and so tends to dissipate into the atmosphere. When confined (for instance inside the trunk) it can reach it's explosive limit, which is from 5% to 15% in air. It is not odourless because an odorant is added to the otherwise colourless and odourless gas. Late model CNG vehicles (built after ECE-R 110) have a lot of safety devices that deal with these properties. An electromagnetic valve mounted at each gastank will close the tank in case of an accident or when the engine or the ignition is turned to the off position. A release limiter will also reduce the amount of gas that can be released in case of a leak in the gas lines. For service of the vehicles or in case the electromagnetic valve fails, the gastank can also be shutoff manually.
- ► 2006 (21)
- ► 2008 (22)