The Center for Science in the Public Interest filed a petition to the Food and Drug Administration (FDA) requesting to ban the use of artificial brown color in Coca Cola and Pepsi.
The colorant is produced from two chemicals, 2-methylimidazole and 4-methylimidazole. Research commissioned by the US Government revealed that these chemicals cause thyroid, liver, lung cancer and leukemia in lab mice and rats and they are potentially dangerous for humans.
The cancerigenic caramel colorants are not related to real caramel which can be made at home by bringing sugar to boil in a pan. An artificial brown color is made by making sugar to react with ammonia and sulfites under pressure at high temperature.
These harmful colorants are also used in soy sauces and dark sorts of beer.