The ignition characteristics of the American Hospital, Portex, polyvinyl chloride, and red rubber tracheal tubes commonly available have been evaluated using a standard carbon dioxide laser. The added hazard of the increased combustibility of the impregnated line on endotracheal tubes and the hazard of commonly utilized anesthetic or lubricating materials are discussed. The safety limits which experimentally, indicate levels of energy and laser burst time which seem to preclude the hazard of ignition are outlined. The potential danger of postburn bronchiolitis is noted, along with appropriate treatment.