Nanoparticle Formation from a Commercial Air Freshener at Real-exposure Concentrations of OzoneDevelopment of a Visibility Monitoring Technique Using Digital Image Analysis

Effect of Temperature on Aerosol Formation Potential for a Terpene-Rich Air Freshener in the Presence of Ozone

“…The relatively higher Y values of α-pinene and d-3-carene means that these species can readily form SOAs when their unit mass is reacted with ozone. In addition, some studies reported that indoor secondary aerosols, formed due to reaction of ozone with a complex VOC mixture emitted from an air freshener, could significantly contribute to indoor air pollution, particularly as regards to particulate matter pollution [19,20,27,31,32,50,51].…”

“…The measured ozone concentration of a background test at a given elapsed time was comparable to the theoretical value, which was used to calculate the amount of ozone reacted in the main experiments. The background test results were reported in a previous study [31]. Briefly, the reference ozone concentration equalled to about 88% of the theoretical ozone concentration.…”

“…Generally, it is clear that the formed particle mass concentration would increase when ozone concentrations increased, as illustrated by equation (3) for the case with enough amounts of VOCs. This was proven by experimental results showing the mass concentrations of particles formed due to the reactions of ozone with VOCs emitted from an air freshener, which became greater with higher ozone concentrations injected [31,32].…”

“…Prior to each experiment, the chamber was flushed twice with pure air and ozone (200 ppb) for 3 h in order to minimize the effects of bag contamination. Thereafter, a background particle formation was checked occasionally by injecting the ozone of 50–200 ppb to the chamber into which no air freshener was introduced into the chamber air, resulting in the measured particle number and mass concentrations of <1800 particles cm −3 and <0.06 µg m −3 , respectively, after 4 h [31]. In this study, every particle mass concentration was derived from the size-resolved particle number concentration data with an assumption of unit particle density.…”

“…Besides concentrations of reactants such as VOCs and ozone, environmental parameters could also significantly affect the formation of SOA in outdoor and indoor environments. Numerous researchers reported that SOA formation is dependent on these parameters, such as ozone concentration [31,32], light intensity [33][34][35], temperature [32,34,36,37] and ventilation [38]. Temperature can significantly change by the hour, day, season, and geographical location.…”