ISO 11439

With rising fuel prices, several countries are changing to alternative fuel with a lot of focus on Natural Gas.
Today there are over 5 million Natural Gas Vehicles (NGV) on the roads world-wide (while the number of Hydrogen powered vehicles remain extremely low).

For Natural Gas Vehicle, if the fuel is in gas form then the container must be able to withstand highpressure along with other safety requirements. This is the CNG cylinder. Many countries accepts ISO 11439 approved CNG cylinders to be used in the vehicle. You can find more information about ISO 11439 on this web site which now mainly focuses on CNG cylinder standard.
(some Hydrogen cylinders are also following requirements in this standard)

Natural Gas running out? Try doing a research on how much natural gas is available underground and under the sea today and this question can be skipped.