The WarmTouch® Pediatric CareDrape includes sheets of polypropylene and polyester which are separated by a layer of moving air. Tests to 16 CFR Sec 1610.4, NFPA 702-1980, and the draft ISO/TC172 assessed the flammability of the materials and of the inflated blanket when exposed to 10 second bursts of energy from one of three medical lasers—focused CO2, KTP, and Nd:YAG—in ambient air and in 98% oxygen. The material did not burn. The material melted away from the laser energy, holes were created, and there were visible fumes, but there was no ignition.
An inflated warming blanket was tested at power levels (5, 10, 15, 20, and 25 watts) that bracketed the power setting most often encountered in laser surgery. The energy beam was centered in a 15 cm circle. In some tests, the laser spot was moved to simulate an inadvertent slicing of the inflated blanket.
The separation caused by the inflation defocused the energy beam. With the Nd:YAG laser, the upper (blue polypropylene) layer was cut open, producing a small flame and a smoke plume. The lower (white polyester) layer reflected most of the energy and sustained little or no damage. The energy from the CO2 laser melted a hole in both the polypropylene and polyester layers of the inflated blanket. Energy reflecting from the steel undersurface cut through the white layer but did not penetrate the top (polypropylene) layer. A blister formed in this layer, preventing the beam from reflecting back.
In all tests, when the energy source was removed, there was no after-flame or afterglow.