Coke and Pepsi are modifying the caramel coloring in their sodas in order to avoid a cancer warning label in California. Coca-Cola insists that this is not another New Coke reformulation. "We are NOT changing our recipe; or our formula," company spokesman Ben Sheidler told AFP in an email. The voluntary change comes in response to a California law that sets limits on chemicals known to cause cancer or reproductive toxicity. This includes the coloring ingredient 4-methylimidazole (4-MEI), which is formed during the cooking process for the caramel coloring used in sodas. California sets a limit of 29-micrograms for 4-MEI in food products. Coke and Pepsi show levels between 103 and 153 micrograms, according to the Center for Science in the Public Interest. The beverage makers worked with their caramel coloring suppliers to reduce the level of 4-MEI in their products. This was largely done to avoid a cancer warning label on their products in California. The beverage makers, though, insist that 4-MEI is not harmful. "The science simply does not show that 4-MEI in foods or beverages is a threat to human health," the American Beverage Association said. The chemical has not been banned by regulatory agencies for use in food and beverages. The Food and Drug Administration is currently reviewing a petition by CSPI to ban 4-MEI. An FDA spokesman told CBS News, however, that someone would have to drink more than 1,000 cans of soda a day to reach the levels shown to cause cancer in rodents. If you are concerned about the harmful effects of 4-MEI, you can always limit how much soda you drink. The American Heart Association suggests no more than three cans a week, which is well under the 1,000 cans a day the mice and rats were drinking.