Coloring: colas, baked goods, pre-cooked meats, soy and Worcestershire sauces, chocolate-flavored products, beer.
Caramel coloring is made by heating a sugar compound (usually high-dextrose corn syrup), often together with ammonium compounds, acids, or alkalis. It is the most widely used (by weight) coloring added to foods and beverages, with hues ranging from tannish-yellow to black, depending on the concentration and the food. Caramel coloring may be used to simulate the appearance of cocoa in baked goods, make meats and gravies look more attractive, and darken soft drinks and beer. Caramel coloring, when produced with ammonia, contains the contaminants 2-methylimidazole and 4-methylimidazole.
In 2007, studies by the U.S. National Toxicology Program found that those two contaminants cause cancer in male and female mice and possibly in female rats. In 2011, the International Agency for Research on Cancer, a division of the World Health Organization, agreed that 2- and 4-methylimidazole are “possibly carcinogenic to humans.”
After that, the State of California’s Environmental Protection Agency listed 2-methylimidazole and 4-methylimidazole as carcinogens under the state’s Proposition 65. Businesses are required to provide a “clear and reasonable” warning before knowingly and intentionally exposing anyone to a chemical on the list, unless exposure is low enough to pose no significant risk. California defines a “no significant risk level” for carcinogens as the amount that would result in no more than one excess cancer case in 100,000 people exposed to the chemical over a 70-year lifetime. California warned that as of January 7, 2012, widely consumed products, such as soft drinks, that contained more than 29 micrograms of 4-methylimidazole per serving would have to bear a warning notice.
In March 2012, when the Center for Science in the Public Interest published the results of a study that found levels up to 150 micrograms of 4-methylimidazole per can of Coca-Cola and Pepsi-Cola purchased in Washington, DC, the soft-drink giants announced that they had reduced the contaminant to below California’s threshold for action in products distributed in California. They said they would market the less-contaminated products throughout the country, which Coca-Cola did in 2013 and PepsiCo was expected to do by 2014. However, according to recent testing, levels of 4-methylimidazole are still high in Pepsi products.
The FDA has a guideline that is 10 times stricter than California’s for regulating substances that are contaminated with cancer-causing chemicals. CSPI’s analysis of a Coca-Cola purchased in 2012 in California found just 4 micrograms of 4-MI per 12 ounces. Even that much lower level might exceed the FDA’s guideline of 1 cancer per million consumers.
It is worth avoiding or drinking less colas and other ammonia-caramel-colored beverages not only because of risk from 4-methylimidazole, but because the drinks contain about 10 teaspoons of added sugars per 12 ounces, and that promotes obesity and tooth decay. Soy sauces, baked goods, and other foods that contain ammoniated caramel coloring are much less of a problem because the amounts consumed are small.
Other relevant links:
• A dangerous additive in breads. See: What Not to Eat: Get This Chemical Found in Breads Out of the Food Supply
• Watch out for toxins and chemicals in seafood. See: Food Safety: Be Careful of These Dangerous Toxins, Pathogens, and Chemicals in Seafood
• An infographic on the FDA’s food additive approval process. See: Not So Safe: How the FDA Lets Food Safety Slip Through the Holes