title: Flammability of esophageal stethoscopes, nasogastric tubes, feeding tubes, and nasopharyngeal airways in oxygen- and nitrous oxide-enriched atmospheres.
abstract: This study determines the flammability of materials in the oral cavity and pharynx during anesthesia in an environment of potentially high oxygen (O2) and nitrous oxide (N2O) concentrations where an ignition source (cautery, laser) may be in close proximity. The materials tested included esophageal stethoscopes, Salem sump nasogastric tubes, enteric feeding tubes, and plastic and rubber nasopharyngeal airways. Flammability was determined using oxidant O2 and oxidant N2O indices of flammability. The oxidant O2 and oxidant N2O indices of flammability are defined as the minimum fraction of oxidant (O2 or N2O) in nitrogen diluent that supports a candle-like flame for a given fuel source. The oxidant O2 index of flammability for esophageal stethoscopes is 0.218, for Salem sump nasogastric tubes 0.229, for enteric feeding tubes 0.192, for plastic nasopharyngeal airways 0.196, and for rubber nasopharyngeal airways 0.172. The oxidant N2O index of flammability for esophageal stethoscopes is 0.430, for Salem sump nasogastric tubes 0.430, for enteric feeding tubes 0.375, for plastic nasopharyngeal airways 0.415, and for rubber nasopharyngeal airways 0.366. These indices are linearly additive.
mesh_terms: D001314:Auscultation / Q000295:instrumentation; D004869:Equipment Safety; D004947:Esophagus; D005390:Fires; D007440:Intubation / Q000295:instrumentation*; D007441:Intubation, Gastrointestinal / Q000295:instrumentation; D009609:Nitrous Oxide; D010100:Oxygen; D010288:Parenteral Nutrition / Q000295:instrumentation; D010969:Plastics; D012408:Rubber
chemical_list: D010969:Plastics; D012408:Rubber; D009609:Nitrous Oxide; D010100:Oxygen