4-Methylimidazole. Ever heard of it? My money is on no. Neither had I until my foodnetindia adventure began.
4-Methylimidazole (4-MEI or 4-MEL) is a chemical present in caramel colour. According to the Wikipedia page on 4-MEI, caramel is the most used food and beverage colouring. It is found in soft drinks, beer, brown bread, chocolates, cookies, gravies, and many other widely consumed food and beverage products. Why am I concerned about 4-MEI? Because there have been studies linking it to cancer.
In 2011, the State of California listed 4-MEI as a carcinogen under the Safe Drinking Water and Toxic Enforcement Act of 1986, better known as Proposition 65.
A 2007 report by the National Toxicology Program in the United States concluded that 4-Methylimidazole caused lung cancer in male and female mice. It also concluded that the chemical may have been associated with the development of leukaemia in female mice.
In 2011, the State of California listed 4-MEI as a carcinogen under the Safe Drinking Water and Toxic Enforcement Act of 1986, better known as Proposition 65. Under the Californian law the "no significant risk" level for 4-MEI is 29 µg/day. Any beverage containing 4-MEI concentrations corresponding to exposure risks greater than 29 µg/day is required to have warning labels.
A 2015 study, led by the Johns Hopkins Centre for a Liveable Future, estimated exposure to 4-MEI resulting from soft drink consumption and estimated cancer risk and/or burden associated with this. The study analyzed soft drinks in California and New York (where unlike California, beverages are not required to display any warning labels regarding 4-MEI). The study found that the concentration of 4-MEI in beverages were always higher in samples purchased in New York, compared to those purchased in California. The study concluded that state regulatory standards appear to have been effective in reducing exposure to carcinogens in some beverages, and also recommended Federal regulation of 4-MEI concentrations in caramel colouring.
As I was unable to locate any studies or material on the 4-MEI content in soft drinks sold in India, I can't say whether or not Indian cola manufacturers follow limits similar to the ones set in California. However, the Food Safety and Standards (Food Product Standards and Food Additives) Regulations, 2011, does specify permissible limits of 4-MEI in food caramel colouring. These regulations specify 200mg per kg to 1000 mg per kg. When translated to what is allowed in a bottle of cola, this sounds very high to me when compared to the California limits.
Since 4-MEI does appear to be a potential food safety hazard, I would limit my soft drink and packaged foods consumption (which I do for other reasons as well, anyway). I would also appeal to the FSSAI to set new limits and impose warning messages on the label for 4-MEI, similar to the California law. Even in the absence of any regulatory compulsions, I think it will be responsible behaviour on the part of all manufacturers, not just soft drinks, to voluntarily reduce the amount of 4-MEI (if it exceeds the Californian limits). After all, isn't it better to err on the side of caution?