Background: Over 600 operating room fires occur annually although many cases go unreported. Over 81% of operating room fires involve surgical drapes, yet limited data exist on the differing degrees of flammability of drapes and other surgical fuel sources in varying oxygen concentrations. The purpose of this study is to assess the flammability characteristics of fuels in the operating room under varying oxygen concentrations.
Methods: Five fuel sources were analyzed in three levels of oxygen: 21%, 50%, and 100%. Three test samples of each material were burned in a manner similar to that established by the Consumer Product Safety Commission. Time to sample ignition and time to complete burn were measured with video analysis.
Results: The median [minimum, maximum] ignition time in 21% oxygen was 0.9 s [0.3, 1.9], in 50% oxygen 0.4 s [0.1, 1.2], and in 100% oxygen 0.2 s [0.0, 0.4]. The median burn time in 21% oxygen was 20.4 s [7.8, 33.5], in 50% oxygen 3.1 s [1.4, 8.1], and in 100% oxygen 1.7 s [0.6, 2.7]. Time to ignite and total burn times decreased as oxygen concentration increased (P < 0.001). Flammability characteristics differed by material and oxygen concentration. Utility drapes and surgical gowns did not support combustion in room air, whereas other materials quickly ignited. Flash fires were detected on woven cotton materials in oxygen-enriched environments.
Conclusions: Operating room personnel should be aware that common materials in the operating room support rapid combustion in oxygen-enriched environments. The risk of ignition and speed of fire propagation increase as oxygen exposure increases. Advances in material science may reduce perioperative fire risk.