Gasoline in Brief
Gasoline is the most common flammable liquid in the world. It’s very volatile, flammable, toxic, and irritating, and has a characteristic odor.
It’s not a pure substance, but rather a mixture of hydrocarbon liquids, ranging from pentane to decane, with hydrocarbon additives that promote smooth burning in an internal combustion engine. In a spill, it burns like other hydrocarbon liquids, generating large amounts of heat, smoke, and carbon monoxide.
Its flash point is -50° F; its ignition temperature ranges from 444° F to 853° F, depending on the grade; and its flammable limits are from 1.2 to 7.6 percent in air. Its specific gravity is 0.74, and it has a minimum vapor density (again, depending on grade) of 2.48. It boils at 140° F, freezes at -131° F, and is not soluble in water.
Gasoline is moderately toxic to humans, both by inhalation and ingestion. The threshold-limit value/time-weighted average (TLV/ TWA) is 300 parts per million, and the short-term exposure limit (STEL) is 500 ppm for 15 minutes.
Inhaling high concentrations will cause depression of the central nervous system, convulsions, unconsciousness, coma, pulmonary edema, and possibly death from respiratory failure or asphyxiation. The liver, kidneys, spleen, and pancreas may also be damaged. Aspiration into the lungs may cause pulmonary edema and pneumonitis severe enough to cause death.
Ingestion will irritate the mouth, throat, and stomach and depress the central nervous system. Contact with the skin will cause reddening and defatting, and contact with the eyes will cause irritation. Many gasolines now contain benzene, which is a known carcinogen.
With its low flash point, gasoline can, at all times, produce enough vapors to form explosive mixtures with the air. Its specific gravity of less than 1 and its insolubility in water indicate that it will float on water and will be spread by the application of water. And with such a high vapor density, its fumes will “hang together,” flowing along and possibly accumulating on the ground, thus producing an extreme hazard.
Emergency response personnel should be protected from contact with the liquid and its vapors by wearing rubber boots and gloves and self-contained breathing apparatus.
