Properties of natural gas

Key properties of natural gas include the following:

• Gas is tasteless, colorless, odorless, and non-toxic (gas is odorized after it enters the delivery system so that leaks are noticed, see odorization for more information)

• While gas is non-toxic, it can result in suffocation by displacing oxygen in confined spaces such as trenches or vaults

• It is gaseous at normal atmospheric temperatures and pressures

• Gas can be liquefied by cooling to about -260 degrees Fahrenheit (-162 °C)

• Gas is lighter than air, so rises when vented in air

• Gas is compressible, meaning that it can be “squeezed” to raise the pressure

• Gas expands when heated and contracts when cooled

• When gas is liquefied it contracts significantly, by about a factor of 600

• As show in the graphic below, combustion occurs only when the air-to-fuel ratio is 5 to 15%.  If the air-to-fuel ratio is above or below this range, gas will not light.