Flammability of common ocular lubricants in an oxygen-rich environment

Approximately 100 surgical fires take place in the United States each year. Recently, an ophthalmic lubricant was blamed for burning a child's eye while oxygen was administered during surgery. This study sought to determine whether four common ocular lubricants would ignite and sustain combustion in an oxygen-rich or standard room air environment.

A model head was modified to allow placement of a cow eye and marked with 1-inch gradations from the eye. A nasal cannula supplied room air and 100% oxygen at flow rates of 0, 2, 4, and 6 L/minute. Four common ocular lubricants were chosen and placed on the eye before attempted ignition. The ignition source (an AccuTemp disposable electrocautery unit and unipolar and bipolar cautery set at 10, 20, and 30 watts) was brought down from the hairline toward the cannula. Each lubricant was tested with each ignition source and each room air/oxygen flow rate.

None of the ocular lubricants ignited under any of the experimental environments tested. A small surface flame was noted with the AccuTemp electrocautery unit, but it did not create a flash fire during the experiment.

The ocular lubricants in this experiment showed no detectable tendency to ignite, even with direct application of the ignition source. Factors such as body hair or oxygen pooling likely provided the conditions necessary for the surgical fire. Most importantly, the ophthalmic lubricants tested actually protected the corneal epithelium and decreased damage to the conjunctiva and lids.