CH-24-C020 - Cooking Emissions from Food for Natural Gas, Propane, and Electric Range Tops

Concerns over residential indoor air quality (IAQ) associated with cooking have shown the need for a better understanding of the emissions generated during the cooking process. Emissions during the cooking process can come from both the food being cooked and the energy source used to cook the food. These emissions include carbon monoxide (CO), nitrous oxides (NOx), VOCs, water vapor and particulate matter (PM) with the latter three being associated with being generated from the food cooked. We developed a test method based on ASTM F1521-12 (Standard Test Methods for Performance of Range Tops) to measure the PM generated by the food during the cooking process, with food products while monitoring the energy being used. The method defines the pan, cooking procedures and food product used, including 80% lean / 20% fat ¼ pound hamburgers. Sampling used an isokinetic collection nozzle with a personal cascade impactor to capture and measure PM emissions. PM emissions were measured for distinct size ranges from ultrafine (less than 0.27 microns) to greater 11 microns, including PM2.5 and PM10. We completed tests using an electric resistance, natural gas and propane rangetop of similar design. The results showed that the electric range consistently generated 2 to 3 times the total PM than the natural gas and propane ranges. Data analysis showed that PM generation is more a function of the surface temperature distribution of the cooking vessel and food product cooked than the energy source. The PM emissions results varied with different batches of the same food product and with the age of the food. The temperature control and temperature distribution of the pan’s cooking surface was also shown to affect the cooking emissions generated. In the tests we completed, the temperature varied more for the electric range and was more difficult to maintain a consistent pan temperature than natural gas or propane. Results showed that cooking emissions as a function of the fuel source are not well understood and require additional testing and evaluations with other range designs and food types to better quantify the impact on indoor air quality from residential cooking.