WASHINGTON (Reuters) - Two of the biggest U.S. meat processors on Tuesday defended a packaging technique designed to keep meat looking fresh at grocery stores even as U.S. lawmakers criticized it as unsafe and misleading.

Packers use carbon monoxide to stabilize the color of meat, but some Democrats said the process misleads consumers by making the products look safer than they really are, and puts the public at risk of eating spoiled meat.

Rep. Bart Stupak, Michigan Democrat and chairman of a House Energy and Commerce subcommittee, called the practice deceptive and “a potential health threat,” and accused U.S. regulators of “turning a blind eye” toward health dangers.

Earlier this year, Stupak launched a probe into the practice and has proposed the use of a safety notice on meat and fish products treated with carbon monoxide.

Since then, food retailers Giant, Safeway Inc and Tyson Foods Inc have stopped the practice.

On Tuesday, discount retailer Target Corp asked USDA for approval to add a warning to the label of meat that has been treated with carbon monoxide sold in its stores.

At the hearing, top executives with Hormel Foods Corp and Cargill Inc told lawmakers they supported a product label encouraging consumers to depend on a “use by” or “freeze by” date rather than color to determine the safety of their meat or fish.

“Consumers are not eating bad product and are not being deceived by this technology,” said Hormel Chief Executive Jeffrey Ettinger.

Some consumer groups have petitioned the Food and Drug Administration to withdraw its approval of sealed packaging that uses a higher portion of carbon monoxide -- 0.4 percent -- than exists in air.

Rep. Marsha Blackburn, a Tennessee Republican, defended the practice on grounds that it reduces the need for human handling and limits the chance of adding bacteria to the meat.

“There is no need for the federal government to implement overzealous regulations that would likely take a step backward and away from safe and efficient meat packaging,” Blackburn said.

Officials at the Food and Drug Administration and U.S. Agriculture Department said they stand by the safety of the carbon monoxide practice and would revisit the process if new data becomes available.

“This is not a priority for the agency with regard to public health,” said Daniel Engeljohn, a deputy assistant administrator with USDA’s Food Safety Inspection Service. The FSIS requires use-by/sell-by dates on meats sold in packages containing carbon monoxide.

The hearing on Tuesday comes as the food industry has been hit hard by several recent recalls.

Among them, Cargill earlier this month recalled more than 1 million pounds of ground beef because of possible E. coli. contamination. It was the second meat recall by the Minneapolis-based company in about a month.

Consumer groups told lawmakers the use of carbon monoxide makes it difficult for shoppers to gauge product safety.

“We’re outraged the FDA put the economic interest of the industry before the health and safety of consumers,” said Wenonah Hauter, director of Food and Water Watch. “At worst (it’s) dangerous, at best it’s a consumer rip-off.”

The FDA regulates about 80 percent of the U.S. food supply, mostly fruits and vegetables, and the USDA is responsible for the rest, including meat, poultry and eggs.