As used in environmental regulations, “fugitive emissions” refers to hazardous air pollutants that escape into the atmosphere from a source that is not supposed to emit pollutants.
Not all air pollutants are considered to be “fugitive.” Gasoline storage tanks, for example, are equipped with vent pipes designed to allow vapors, that build up within the tanks, to be discharged. The vapors which emerge through these pipes are not fugitive vapors; they are expected to come out through the end of a vent pipe.
But when gasoline vapors escape into the atmosphere through pumps, valves, and other components that are supposed to be vapor tight, they are said to be fugitive emissions.
