BOISE, Idaho - Worried about the market for Idaho potatoes, the state is asking California Gov. Arnold Schwarzenegger to drop a proposal that could require signs in restaurants and stores warning that french fries may cause cancer.

For two years, California has been revising a 1986 citizen's right-to-know law to address carbohydrate-rich foods, where a carcinogen known as acrylamide occurs naturally when the foods are baked or fried. Acrylamide is known to cause cancer in mice, and the substance has been found in french fried potatoes.

Idaho Gov. Dick Kempthorne wants potatoes - which account for $2 billion of the state's economy - exempted from the California law. He worries that warnings could stoke fear among consumers and dent potato sales that already have been hurt by low-carbohydrate diet trends.

"It could have negative economic impact on interstate commerce," said Mike Journee, a Kempthorne aide. "How are you going to get away from something that's naturally occurring?"

Risk levels for acrylamide were added in 1990 to California's Proposition 65, a law meant to protect residents from chemicals known to cause cancer and birth defects.

At the time, the chemical was generally thought of as an industrial agent, used in food packaging and to treat sewage, according to the U.S. Department of Health and Human Services. But in 2002, a Swedish National Food Authority study reported that acrylamide occurred naturally in some starch-rich foods as a result of cooking or heat processing.

The U.S. Food and Drug Administration is currently assessing the chemical in food.