The oxygen and nitrous oxide indices of flammability of endotracheal tubes determined by laser ignition.

This study determines the flammability of polyvinylchloride (PVC), red rubber (RR), and silicone (Si) endotracheal tubes in oxygen- and nitrous-oxide-enriched atmospheres. Flammability is measured by using the oxygen and nitrous oxide indices of flammability with laser ignition. The laser-ignited oxygen (O2) index of flammability of the endotracheal tubes is: PVC, 0.25; RR, 0.19; Si, 0.20. The laser-ignited nitrous oxide (N2O) index of flammability of the endotracheal tubes is: PVC, 0.45; RR, 0.37; and Si, 0.41. These results are similar to the previously reported O2 and N2O indices of flammability with propane-torch ignition. This study validates the concept that the indices of flammability are useful measures of endotracheal tube flammability and are independent of the ignition source.