Ethanol, once hailed as an alternative to high gas and oil prices with spinoff benefits, is drawing a backlash as food prices soar and environmental consequences emerge.

Recently 24 Republican senators asked the Environmental Protection Agency to reconsider regulations requiring ethanol production to increase by five times, to 36 billion gallons, by 2022. Currently ethanol accounts for about 5 percent of the nation's fuel supply, but that would rise to 22 percent over the next 15 years.

The EPA can waive the renewable-fuel requirements if it determines that they cause harm.

Ethanol is a corn-based gasoline additive. Its production has been encouraged by federal subsidies along with tariffs on foreign supplies. However, it also siphons off food supplies to meet fuel demands, creating corn shortages and contributing to the rising price of corn and other products dependent on it.

"This subsidized (ethanol) program — paid for by taxpayer dollars — has contributed to pain at the cash register, at the dining room table, and a devastating food crisis throughout the world," Sen. John McCain, GOP presidential candidate, said.

The lawmakers have support from some large food companies such as Kraft, which has hired a lobbyist to argue against using corn in biofuels. Texas Gov. Rick Perry, a Republican, is seeking a 50 percent waiver from the renewable fuel requirements.

But food prices aren't the only cause for concern. Ethanol, which has been touted as an environmentally sound alternative to gasoline, has its own adverse consequences. It requires more energy to manufacture, and cars get lower gas mileage with it. Ethanol also costs more than gas — all reasons to take another look at food-to-fuel mandates.