PepsiCo (NYSE:PEP) is the focus of a report from The Center of Environmental Health in which it's alleged the beverage maker is still using a chemical linked to cancer in rodents. Over a year ago, both PepsiCo and Coca-Cola pledged to stop using 4-methylimidazole as part of its caramel coloring, but testing by the watchdog group showed the presence of the chemical in Pepsi products sold outside of California.