Food & Beverages

Pepsi contains a cancer-causing chemical

In 2011, the state of California listed 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.

In late 2011, CEH began investigating and testing colas for 4-MEI. After tests found some products with high levels of the chemical, we confronted the cola companies, and 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 in to the rest of the country.

In 2013, CEH investigated to see if Coca-Cola and Pepsi were following up on their promises. We collected Coke and Pepsi cola products from ten states and California, and sent them to an independent lab for testing. Our findings: both companies products from California were safe, and Coke products from nine out of ten states were also virtually free of 4-MEI. But all ten Pepsi products from outside California still had high levels of the cancer-causing chemical. Our results made national news and forced Pepsi to announce they would reformulate their products nationwide. The company now claims their products will be reformulated nationally by February 2014.

For more information about our cola testing, see our press release, One Year Later, Pepsi Still Contains Cancer-Causing Food Coloring, and the USA Today Story, “Environmental group finds carcinogen in Pepsi“.


In 2012, the California Department of Public Health identified plum candies, candied ginger, and licorice that were contaminated with lead in violation of California law. CEH conducted additional testing and identified almost 100 companies selling contaminated candy.

For more information about our candy testing, see our press release, Health Watchdog Launches Legal Action on Lead-Tainted Plum and Ginger Candies, and the ABC News video coverage of it.