The agency’s announcement comes in response to a study by Consumer Reports that shows 12 brands of soda have varying levels of 4-methylimidazole — an impurity found in some caramel coloring.
The FDA says it has studied the use of caramel as a flavor and color additive for decades but will review new data on the safety of 4-methylimidazole. The agency did not provide details about the data.
“These efforts will inform the FDA’s safety analysis and will help the agency determine what, if any, regulatory action needs to be taken,” said FDA spokeswoman Juli Putnam.
There are no federal limits on the amount of 4-methylimidazole in food and drink. The substance is formed in some caramel coloring at low levels during the manufacturing process. The FDA says it also can occur in trace amounts when coffee beans are roasted or some meats are grilled.
The Consumer Reports study urged the agency to set a maximum level of the substance when it is artificially added to foods or soda, to require labeling when it is added and to bar products from carrying the “natural” label if they contain caramel colors.
“There is no reason why consumers need to be exposed to this avoidable and unnecessary risk that can stem from coloring food and beverages brown,” said Consumer Reports’ Dr. Urvashi Rangan, a toxicologist and lead investigator on the study.
Though studies have not been conclusive about whether 4-methylimidazole is a carcinogen, California includes it on the state list of carcinogens and a state law mandates a cancer warning label on products that have a certain level of the substance. In reaction to that law, Coke, Pepsi and other soft drink makers have directed their caramel-color suppliers to reduce the levels of 4-methylimidazole. It is not found in all caramel colorings.
Over an eight-month period, the study found that single 12-ounce servings of two beverages purchased in California, Pepsi One and Malta Goya, exceeded the 29 micrograms of 4-methylimidazole that are the threshold per day in California but carried no warning. Consumer Reports has asked the California attorney general’s office to investigate; a spokesman for the attorney general says the office is reviewing the request.