In the interest of eliminating all carcinogens from the food supply, the state of California has the strictest food additive regulations in the country (if not the world,) and now the grand dames of American softdrinks--Coke and Pepsi--have finally run afoul of the regulators' rulebook. You might imagine the problem would be with the controversial artificial sweeteners used in diet sodas, but it's not. At issue is a chemical contaminant called 4-methylimidazole, dubbed 4-MEI, that can develop during the manufacturing process of the drinks' most basic coloring agent known as "caramel coloring."
Because the agent that gives cola its brown color can contain the carcinogenic compound 4-MEI at levels as much as 6 times higher than what California deems safe, companies using the agent would have to put a cancer warning label on their products.
The trouble began last year after environmental scientists at the government's National Toxicology Program (which conducts safety testing and helps set standards for the National Institute of Environmental Healh) found "clear evidence" that 4-MEI is an animal carcinogen linked with lung, liver and thyroid cancer as well as leukemia in mice. California state health officials then added 4-MEI to the state's list of "chemicals known to the state to cause cancer." Under Proposition 65, California regulators then set a maximum safe level for the chemical, requiring any food or beverage containing more than the safe level to carry a cancer warning label.
Researchers at the University of California at Davis and the Center for Science in the Public Interest (CSPI) independently found significant levels of 4-MEI in multiple brands of cola including Coke, Pepsi and Wholefoods 365 Cola. The Golden States' maximum safe level of 4-MEI is 16 micrograms per person per day from any individual product. Popular brands of cola contain about 200 micrograms of 4-MEI per 20-ounce bottle—and many people, especially teenaged boys, consume more than that each day according to CSPI, which has taken a lot of heat for exposing the soda problem.
In contrast to the caramel one might make at home by melting sugar in a saucepan, the artificial brown coloring in colas and some other products is made by reacting sugars with ammonia and sulfites under high pressure and temperatures. CSPI also says the phrase “caramel coloring” is misleading when used to describe colorings made with ammonia or sulfite: "The terms `ammonia process caramel' or `ammonia sulfite process caramel' would be more accurate," the consumer group stated in a press release,"and companies should not be allowed to label any products that contain such colorings as 'natural.'”
In response to the controversy, Coca Cola and Pepsi coloring manufacturers to modify their production process to reduce the amount of 4-MEI in the coloring agent. In a statement, Coca Cola insisted the change would have no effect on the formula or on the taste. It will also have no effect on the unhealthy level of sugar found in regular soda.