Commercial jets fly at airspeeds high enough to make conventional gasoline-based fuels too risky to use. A special formulation of fuel and anti-freeze allows these airplanes to fly safely.
A fuel mixture known as Jet-A powers modern commercial airliners, according to the U.S. Centennial of Flight Commission website. This fuel mixes pure kerosene with anti-freeze and burns at temperatures at or above 120 degrees Fahrenheit.
Kerosene-based fuels have a much higher flash point than gasoline-based fuels, meaning that they ignite at significantly higher temperatures. This property becomes essential at jet aircraft speeds, where friction from surrounding air can create heat. At the same time, the anti-freeze in Jet-A keeps ice out of the fuel tanks.
The U.S. Centennial of Flight Commission states that Jet-A must pass stringent purity tests to ensure its quality before commercial jets can use it. Railroads and other ground transportation facilities can often use Jet-A that has too many impurities for commercial jets.