An environmental grouphas cautioned that the caramel colouring used in Pepsi still contained carcinogen levels that were a cause for worry, even after PepsiCo said it would change its formula.
Both PepsiCo Inc and Coca-Coal Co said they would adjust their formulas nationally with California passing a law mandating drinks containing a certain level of carcinogens must bear a cancer warning label.
The companies had made the changes for drinks sold in California with the passage of the law.
The chemical 4-methylimidazole, or 4-Mel could form during the cooking process and may consequently be found in trace amounts in many foods.
According to watchdog group The Center for Environmental Health, the tests it conducted revealed that while Coke products no longer tested positive for the chemical, Pepsi products sold outside of California still did.
According to Pepsi, its caramel colouring suppliers were changing their manufacturing process to reduce the amount of 4-Mel in its caramel. That process was complete in California and would be finished in February 2014 in the rest of the country. Pepsi said it would also be taken out globally, though it did not indicate a timeline.
Meanwhile, according to the company, the FDA and other regulatory agencies around the world considered Pepsi's caramel colouring safe.
It appeared that while both companies had managed to complete the transition for sodas sold in the state of California, new analysis showed that all 10 of the 10 samples of Pepsi products purchased nationwide during the month of June (in locations outside California) contained levels of 4-MEI that were around four to eight times higher than the safe limits set by California.
As against this, nine of the 10 samples of Coke products purchased in locations outside California contained little or no trace of 4-MEI.
"We applaud Coke," wrote Michael Green , executive director of the Center for Environmental Health, in a release announcing the findings.
"Pepsi's delay is inexplicable," Green added. "We urge the company to take swift action."
A Pepsi spokesperson told a blog about foodstuff, that sodas sold throughout the US would be able to transition to the colouring by February 2014. According to the company efforts were on to switch the colour formulation for sodas distributed globally.
"The FDA and other regulatory agencies around the world, including the European Food Safety Authority and Health Canada, consider our caramel colouring safe for use in foods and beverages," Pepsi Co wrote in an email to The Salt.