An analysis found Pepsi cola drinks sold in 10 states still contain the carcinogen 4-methylimidazole, or 4-MeI, in its food coloring, the California-based Center for Environmental Health said in a statement.
In March 2012, both Coca-Cola and Pepsi said they would change the formulation of their caramel food colorings to be in compliance with a California law requiring labels on products that contain 4-MeI.
CEH Executive Director Michael Green charged that Pepsi's delay was "inexplicable," noting Coke had made the change.
Colas sold by both companies in California comply with the law, Green said.
An analysis by an independent lab commissioned by CEH found "little or no" 4-MeI in nine out of Coke products sold in 10 other states, the center's statement said. However 'high levels" of the chemical were found all Pepsi cola products sold in those same states.
The lab found that colas sold by Pepsi outside of California had levels of 4-MeI four to eight times higher than levels considered safe in California.
In an e-mail to CEH, Pepsi's senior director, Aurora Gonzalez, defended the company's work in eliminating 4-MeI.
"Our caramel coloring suppliers have been working on modifying the manufacturing process to reduce the amount of 4-MEI," she said. "As you know, 4-MeI levels in our products in California are below Prop 65 levels. The rest of the U.S. will be completed by February 2014. In fact, we'll be starting the process and shipping concentrate end of this year."