Cannula Burn-Back Evaluation

Medical oxygen is supplied to patients via clear plastic tubing known as a canula. If an external ignition mechanism is strong enough to melt the plastic and expose the oxygen, then the canula can be kindled and as long as oxygen is continually supplied, it will continue to burn like a fuse until it is completely consumed. The canula material burns with a large amount of localized energy release that can easily kindle surrounding materials flammable in air such as clothing, sheeting, bedding, carpets and wood. The majority of fires that have led to canula ignition are caused by smoking, but some other ignition sources include irons, stove tops and heaters.

WHA has the capability to evaluate whether a burning canula can regress further once it has reached the component that is supplying the oxygen. Components include concentrators, regulators, conservers, and portable liquid oxygen vessels. Fire-break devices designed to extinguish the fire and shut-off the oxygen gas flow are available and can be tested for performance evaluation. Testing can be performed according to ISO 8359 Amendment 1 Section 56.12 or customized as requested.

Video Description: When gaseous oxygen from a concentrator, oxygen cylinder or other medical oxygen supply is flowing through a cannula, the cannula tubing, if ignited, can burn back towards the source of the oxygen and the resulting fire can potentially ignite other nearby flammable materials along its path.