Comparison of Combustion Emissions from Wickless- and Wick-based Candles
Dr. Dale Stephenson
The use of wickless candles is becoming a popular way to produce pleasing aromas in what is marketed as a safe and soot-free manner. While it is true that these candles do not use a flame to combust scented wax, the question yet to be answered is whether using a flameless source to disperse its aroma into a given environment reduces airborne emissions (i.e. is soot-free). The purpose of this study was to compare combustion emissions from wickless- and wick-based candles in a controlled setting. This was accomplished through the performance of sampling trials in a specially designed environmental chamber. Equal combustion times were performed among all trials and the environmental chamber was sterilized prior to the start of a new trial. For the trials using wickless candles different heat source temperatures were used to disperse the scented wax to determine if emission concentration was function of temperature. The quantification of emission concentrations was accomplished using time-integrated and direct reading instrumentation. The types of emissions quantified were PM10, PM2.5, CO, and CO2. Preliminary results of this study suggest that compared to their wick-based counterparts, wickless candles produce lower concentrations of PM10 and PM2.5, with no statistical difference in concentrations observed in the production of CO and CO2. Study results further suggest that lower heat source temperatures generate lower concentrations of PM10 and PM2.5. It is hoped that the results of the study will provide scientific information to the general public concerning the type and level of contaminant emissions generated during the use wickless candles so that individuals can make an educated choice when purchasing this consumer product.