It's been a problem-filled couple of months for caramel coloring.
After saying it found unsafe levels of 4-MEI in cans of Coca-Cola, Pepsi-Cola, Dr. Pepper and Whole Foods' 365 Cola, The Center for Science in the Public Interest petitioned the FDA in March to ban the use of caramel colorings that contain 4-MEI, citing a possible cancer risk.
While FDA regulators quickly responded by asserting that soft drinks containing caramel coloring with 4-methylimidazole, also known as 4-MEI or 4-MI, poses no health risk to consumers, they agreed to review the petition.
Meanwhile, California regulators earlier this year began enforcing their 2011 decision to add 4-MEI to the state's list of "known carcinogens." California's controversial Proposition 65 (see our article California's Prop 65 Applies to You) would require the colas and other consumer products containing at least 29mcg of 4-MEI per serving to carry a warning label claiming they contain a possible carcinogen.
Rather than add that frightening label declaration, both PepsiCo and Coca-Cola asked their caramel color suppliers to alter their manufacturing processes to reduce the level of 4-MEI to below the limit set by California, the only state that regulates the substance. Dr Pepper Snapple Group said all the caramel color being produced for it meets the new California standard.
"New chemical analyses (commissioned by CSPI) have found (these beverages) contain high levels of 4-methylimidazole, a known animal carcinogen," wrote CSPI in its March petition. "The carcinogen forms when ammonia or ammonia and sulfites are used to manufacture the ‘caramel coloring' that gives those sodas their distinctive brown colors."
FDA classifies caramel color as generally recognized as safe (GRAS). So do regulatory agencies around the world, including the European Food Safety Authority (EFSA), which concludes "these caramel colors are neither genotoxic nor carcinogenic."
4-MEI is found in a wide variety of commercially produced foods and beverages, including pet food, alcoholic beverages, soft drinks, sauces, baked goods and breads, molasses, coffee beans, chocolate and some beers. Plus grilled steaks – the trace element is created naturally from cooking the sugars in foods and beverages during the heating, roasting or cooking process. It's what gives those foods a rich, brown hue.
In its 2011 FDA petition on the same subject, CSPI noted that 2-methylimidazole and 4-methylimidazole, which form when sugar is mixed with ammonia and sulfites to create caramel coloring, have been shown to cause lung, liver and thyroid cancer in mice and rats.
When the State of California's Office of Environmental Health Hazard Assessment added the compound to its list of known carcinogens in 2011, it created a labeling problem for the soda industry, in particular, and other food and beverage manufacturers as well.
With no regulatory hearing or review, California rule makers based their ruling on the results of a 2007 study from the National Toxicology Program, which found that 4-MEI at high doses caused lung cancer in rats and mice. But even NTP officials question California's decision.
In a letter to OEHHA opposing the listing of 4-MEI, Ernest E. McConnell, former director of the NTP's Toxicology Research and Testing Program, wrote: "NTP has not included 4-MEI on its list of chemicals causing cancer," and concluded, "4-MEI does not have sufficient evidence of carcinogenicity to be placed on the list."