Gasoline storage and dispensing operations at retail service stations
and private facilities release ROG vapors containing listed substances
into the atmosphere. These emissions occur during underground storage
tank loading, tank breathing, spillage, and vehicle refueling.
Emission rates are highly dependent upon the installation and
performance of Phase I and Phase II vapor recovery equipment. The
primary components of gasoline vapor are benzene, hexane, toluene,
xylenes, and a mixture of other nonmethane hydrocarbons. Actual vapor
concentrations of each component will vary depending upon the
composition and temperature of the gasoline.