PepsiCo and Coca-Cola are modifying their caramel coloring to avoid a cancer warning label now required by a new California law when potential carcinogens exceed certain levels. Both the soda giants and the American Beverage Association (ABA) have stressed that they believe that the amounts of the chemical at issue, 4-methylimidazole (4-MI) in traditional caramel-coloring formulations pose no public health risks. However, having asked suppliers to change their coloring formulations to reduce 4-MI levels in sodas distributed in California, Coca-Cola and PepsiCo are now implementing the changes across their manufacturing processes, reported Associated Press. The Center for Science in the Public Interest (CSPI) recently released results of lab tests finding that some samples of Coke, Diet Coke, Pepsi, Diet Pepsi, Dr Pepper and Diet Dr Pepper contained levels of 4-MI signficantly exceeding California's 29-micrograms-per-12-ounce-serving benchmark, and that some exceeded the FDA's benchmark of a lifetime risk of one cancer in one million people. For the second time, CSPI petitioned the FDA to ban caramel colorings that contain 4-MI, which it describes as a "known animal carginogen." The FDA will review the petition, but told Reuters that a human being would have to drink more than 1,000 cans of soda per day to reach the doses administered in the studies that have shown links to cancer in rodents. The ABA said that California added caramel coloring to its list of carginogens based on a single study in lab mice and rats, with no studies demonstrating that it causes cancer in humans, reported Associated Press.