In November, Praxair launched a recall of its Grab 'n Go Vantage Portable Oxygen Cylinder, and now the FDA has slapped a Class I label on the move, warning that fires can start inside the unit and put patients in danger. The fires can be caused by dropping or knocking the tanks over, and, while they are self-extinguishing, they can result in burns and lack of oxygen for patients, the FDA said. Praxair is replacing a ring within affected units as they come in for regular servicing, but the company says unmodified tanks are still safe for use so long as customers store them properly. More