Ethanol is a fuel made from various plant materials, which collectively are called “biomass.” Nearly half of U.S. gasoline contains ethanol in a low-level blend to oxygenate the fuel and reduce air pollution. Ethanol as E10 (10% ethanol) is blended into many gasoline formulations and sold right at the pump.  Higher concentrations of ethanol like E85 are available at gas stations as separate pumps and can be used in flexible fuel vehicles.