A study was conducted to analyze the competency of several types of electric cooktop ranges to evaluate the likelihood of them igniting a variety of common kitchen items. Three types of electric cooktop ranges were tested including a ceramic-glass cooktop range, an electric coil cooktop range, and an electric coil cooktop range with a Safe-T-element installed. The latest research was reviewed to select a representative sample of fuels commonly noted as the first fuel ignited. The eight selected fuels included cardboard (pizza box), a cotton dish towel, a roll of paper towels, a pan of canola oil, a pan of vegetable oil, a nylon short turn spatula (cooking utensil), a kitchen appliance (toaster), and a plastic storage container.
Each range was tested in the high, medium, and low thermostat settings on the large (8” diameter element) and the small (6” diameter element) resulting in a total of 48 tests per range type. A variety of data was collected for each test including video photography, infrared video photography, still photography, and thermocouple data. The heat sources were characterized using both thin skin calorimeters and heat flux transducers (radiometers).
The rate of temperature rise was found to be slowest with the Safe-T-Element, reaching its maximum temperatures 8-13 minutes slower than its ceramic-glass and electric coil counterparts. When the thermostat for the cooktops was placed on high, 85% of the time ignition occurred, regardless of the cooktop type. The high setting for all three ranges showed the maximum potential for ignition based on the total heat output produced by the 6-inch diameter and 8-inch diameter heating elements. 37.5% of the fuels tested on the ceramic-glass cooktop ignited at the medium setting, while only 18.75% and 6.25% of fuels ignited on the electric coil and Safe-T-element cooktops respectively. No ignition of any fuel occurred when the cooktop thermostats were placed on the low setting. In total, the electric coil cooktop resulted in ignition 39.5% of the time, Safe-T-element 35.4% of the time, and ceramic-glass cooktop resulted in ignition 31.25% of the time. Therefore, it can be concluded from these tests that all of the cooktops were similar in ignition competency for the provided fuels. Furthermore, it was found that when ignition did occur in similar fuels on different cooktops, that the Safe-T-element cooktop provided more time before ignition.
This study has validated a number of configurations of electric cooktop ranges in a variety of ignition scenarios. The competency of aforementioned cooktops as an ignition source given a number of common household fuels has been reported on in extensive detail within the body of this report.