Environmental watchdog Greenpeace has branded McDonald's and Coca-Cola 'dirty' Olympic sponsors. Greenpeace spokesperson Corin Millains said that the companies planned to use global-warming hydrofluorocarbons (HFCs) in their refrigeration systems at Olympic venues in contradiction of the guidelines for the Sydney games. "They have forgotten about the green games in their race for marketing and profits," Millias said. "The green games is under threat from dirty sponsors."