Be observant for leaks. Although leaks
on natural gas pipelines are rare, be observant for dirt or water being
ejected in the air, dead or dying vegetation (in an otherwise normal area)
over or near pipeline areas, flames coming from the ground or appearing
to burn just above the ground, a roaring, blowing or hissing sound near
a pipeline, or a
distinct odor of natural
gas.
Fortunately, natural gas is lighter than air, and thus, can dissipate into
the air rapidly, making accidental combustion difficult. To further prevent
accidents, natural gas has a very high ignition temperature, at about 1100
degrees Fahrenheit. This is nearly twice the ignition temperature for gasoline.
These factors make accidental ignition or combustion of natural gas less
likely. However, high concentrations of gas in a confined space may increase
the danger of an explosion if triggered by a spark or flame.