The US Environmental Protection Agency (EPA) is mulling over a proposal that will mandate all gasoline consumers to purchase a minimum four gallons of gasoline from certain gas pumps, post introduction of the E15 ethanol-gasoline blend into the market.

The EPA will require retail stations to offer the same hose and nozzle for both E10 and E15 blends and use appropriate labels that inform customers of the minimum purchase requirement.

EPA National Vehicle and Fuel Emissions Laboratory member Byron Bunker in a letter to the American Motorcyclist association wrote, "Additionally, EPA is requiring that retail stations that offer E10 and E15 from the same hose and nozzle use additional labeling to inform consumers about the minimum purchase requirement."

E15 is a formulation that contains up to 15 percent ethanol by volume.

Ethanol is primarily grain alcohol produced from crops such as corn and mixed with gasoline to produce an ethanol-gasoline blend motor fuel.