Aerosol-type insecticides are one of the most widely used household insecticides to control mosquitoes. Not only the structural difference such as the size and shape of orifice, but also the difference in formulation including solvent system and proportion of propellent can affect the efficacy of those aerosol products. Orifice structure can be represented by nozzle diameter while solvent systems are divided into water-based and oil-based types in wide view. In the present study using Asian Tiger Mosquito, Aedes albopictus, we found that the orifice nozzle size made a significant difference in shoot-out range, followed by heterogeneous mortality by distance. Additionally, oil-based spray affected farther space than water-based one. Oil-based solvent system was also responsible for lowering the LT50 and KT50(knock-down time 50) values. Therefore, they are one of the definitive parts in insecticides formulation that determine the way of insecticide delivery. In terms of insecticide resistance management, we define efficiency of insecticide as the proportion of insecticide treated to environment that is solely acted as toxin to target pest. The higher efficiency of insecticide, the less overused chemicals we face, which may imply lower risk of resistance development. Thus, we argue that formulations, the specific route of insecticide discharge to environment, should be deliberately considered not only for consumer satisfaction, but also for insecticide resistance management.

Secondary air pollution can be caused by aerosol formation through reactions of ozone and volatile organic compounds (VOCs) emitted from household products used in the indoor environment. In this study, we investigated the potential for aerosol production during the reactions of ozone and VOCs emitted from a home insecticide, a popular commercial product extracted from natural ingredients, in a 1-m³ reaction chamber. The major chemical component of the test product was prallethrin, which has very high efficacy of mosquito and housefly elimination. Toluene, α-pinene, cymene, d-limonene, α-terpinene, and α-thujone were also identified as constituents of the insecticide. Injected ozone concentrations of 50, 100, and 200 ppb generated particle mass concentrations, corrected for wall loss and air exchange loss, of 7.3, 33.1, and 40.0 μg/m³, respectively, after a 4-h reaction time. These concentrations are lower than those generated by an air freshener in a previous study under the same experimental conditions. It was concluded that the home insecticide tested had the potential to initiate secondary aerosol formation under ozone exposure due to the biogenic VOCs it contained.