Grease thefts have spiked whenever fuel prices climbed during the last four years and this spring is no different, according to Tom Cook, president of the National Renderers Association.

“It’s on the rise and it’s because of higher oil prices,” Cook told Reuters in a telephone interview. “I have one member who told me it’s costing his business $1 million a year.”

Recyclers typically contract with restaurants to pick up the waste product. The grease is cleaned and sold for use as biofuel, livestock feed and other products.

An Omaha recycler has filed theft reports with police in Omaha and Lincoln in Nebraska, and Sioux City, Iowa. Thieves recently stole about 4,200 pounds (1,909 kgs) of used grease from six Lincoln fast-food restaurants.

Processed fryer oil is not trash. It is called yellow grease and is traded. Its value is driven by higher prices of gas and ethanol.

Recyclers and collectors pay restaurants about 18 cents a pound for grease. After further processing, it can be sold for 42 to 45 cents a pound, said Cook, who is based in Alexandria, Virginia.

Yellow grease was trading for less than 8 cents a pound in 2000.

Cook said he plans to conduct an industrywide survey to determine the extent of the losses. Many restaurant owners don’t realize what they are losing and local law enforcement agencies have other crime-fighting priorities, he said.

One way to curb demand for stolen grease is to alert potential buyers, especially in the feed industry, to only buy from known sources to ensure the product they receive is free of impurities and moisture, Cook said.