The Renewable Fuel Standard, passed four months ago, is under fire while food costs escalate, The Hill, a Washington newspaper, reported Thursday.
RFS calls for annual production of 36 billion gallons of ethanol -- 15 billion gallons coming from corn -- by 2022.
"We don't know how much of the food crisis was caused by it, but nobody expected it to cause much," U.S. Sen. Pete Domenici, R-N.M., said.
Senate Energy and Natural Resources Committee Chairman Jeff Bingaman, D-N.M., said "it's something we need to look at."
Grocers, oil companies and livestock producers have lobbied against the mandates.
Texas Gov. Rick Perry has asked for a waiver on the ethanol mandates, complaining that rising corn prices are costing the Texas livestock industry millions every year.
Now that food prices are rising "a lot of lawmakers are wondering who the hell they woke up with," Scott Faber, Grocery Manufacturers Association vice president for federal affairs told The Hill.