NEW YORK (AP) - An environmental group said Wednesday that the caramel coloring used in Pepsi still contains a worrisome level of a carcinogen, even after the drink maker said it would change its formula.

In March, PepsiCo Inc. and Coca-Cola Co. both said they would adjust their formulas nationally after California passed a law mandating drinks containing a certain level of carcinogens come with a cancer warning label. The changes were made for drinks sold in California when the law passed.

The chemical is 4-methylimidazole, or 4-Mel, which can form during the cooking process and, as a result, may be found in trace amounts in many foods.

Watchdog group The Center for Environmental Health found via testing that while Coke products no longer test positive for the chemical, Pepsi products sold outside of California still do.