Why it Matters

Thanks to CEH’s work, a cancer-causing chemical in Coca Cola and Pepsi is no longer a public health risk. In 2011, the state of California identified 4-methylimidazole (4-MEI) as a chemical known to cause cancer. The chemical is created in the industrial production of caramel coloring, so products that contain large amounts of caramel coloring often contain high levels of 4-MEI. Coca Cola, Pepsi, and other colas use large amounts of caramel coloring to give their products their typical dark-brown hue. The companies knew of the carcinogen in their colas for decades, but went on with business as usual.

What We Did

In late 2011, CEH began investigating and testing colas for 4-MEI. Our scientists and researchers tested products and built a body of irrefutable evidence. We exposed what these mega-corporations were doing behind closed doors and demanded that they stop hurting their consumers. In March 2012, Coke and Pepsi announced they would change their caramel coloring to eliminate risks from 4-MEI. At the time, both companies stated they would start selling their reformulated cola in California first, and would then phase it into the rest of the country.

Coke immediately took steps to remove the toxin. Pepsi made promises, but some were empty. More than a year later, our results showed that Pepsi products still contained the carcinogen. So, we sued them and finally, after three years of pushing, CEH persevered. In 2015, Pepsi agreed to reduce the amount of the chemical in its products. CEH forced these two giant corporations to remove cancer-causing chemicals from two of the most beloved, best-selling products of all time.

What You Can Do

Always purchase organic drinks whenever possible and affordable.


CEH Press Release: Pepsi Agrees to Limit on Caramel Coloring Chemical in Colas
CEH In the News: Environmental group finds carcinogen in Pepsi
CEH In the News: Coke Changed Caramel Color to Avoid Cancer Warning; Pepsi in Transition