Pepsi announced this week that it plans to remove a controversial chemical from soda sold in the US, more than a year after the state of California labeled it a carcinogen. The move was spurred by a report from the Oakland-based Center for Environmental Health (CEH), which found that PepsiCo's sodas still contain the chemical methylimidazole, or 4-MEI — a compound found in caramel coloring agents used in sodas, soy sauce, beer, and bread.

Studies from the National Toxicology Program found that mice exposed to 4-MEI for long periods had higher rates of lung cancer. In its report, published Wednesday, CEH acknowledged that Pepsi sodas sold within California contain lower amounts of 4-MEI, in compliance with state law, though beverages sold elsewhere in the US still have high levels of the chemical. California law requires labels for all foods that contain cancer-causing agents, which is what spurred both Coca-Cola and Pepsi to reformulate their caramel coloring.

"We strongly refute any claim that any product we sell anywhere is unsafe."

In response, PepsiCo said its suppliers are working on lowering the amounts of 4-MEI used in coloring agents, and that the company plans to sell sodas with lower levels of the compound across the rest of the US by February 2014. The company elaborated upon its defense on Friday, in a statement provided to Bloomberg Businessweek.

"We strongly refute any claim that any product we sell anywhere is unsafe. The safety of our products is PepsiCo's top priority, and we abide by the regulatory guidelines everywhere we do business," the company said. "While we meet the strict FDA guidelines, when the regulatory requirements changed in California PepsiCo moved immediately to meet the new requirements and, in order to maintain a harmonized supply chain, globally committed to rolling out the changes across the rest of the US and internationally."

"FDA has no reason to believe that there is any immediate or short-term danger."

CEH noted that it did not find elevated levels of 4-MEI in any other products, including Coca-Cola, which recently adopted a different caramel coloring agent. Federal regulators, meanwhile, have yet to weigh in on the safety of 4-MEI. An FDA representative told Bloomberg Businessweek that the agency is continuing to review studies on the chemical, though there are currently no signs that it poses a serious health hazard.

"Based on the available information, FDA has no reason to believe that there is any immediate or short-term danger presented by 4-MEI at the levels expected in food from the use of caramel coloring," the spokesperson said.