US group claims Pepsi contains carcinogen

In March, Pepsi and Coca-Cola both said they would adjust their formulas nationally after the US state of California passed a law mandating drinks containing a certain level of carcinogens come with a cancer warning label. The changes were made for drinks sold in California when the law passed.

The chemical at the centre of the controversy is 4-methylimidazole, or 4-Mel, which can form during the cooking process and, as a result, may be found in trace amounts in many foods.

Watchdog group The Center for Environmental Health found via testing that although Coke products no longer tested positive for the chemical, Pepsi products sold outside of California still had.

Pepsi said the company's caramel colouring suppliers were changing their manufacturing process to cut the amount of 4-Mel in the caramel used. That process is complete in California and will be completed in February 2014 in the rest of the country. Pepsi said it will also be taken out