Terpenoid substances, aldehydes and lactones are common substances in scenting products, and a majority of the compounds used are reactive enough to be susceptible to indoor chemistry (Nazaroff and Weschler, 2004; Singer et al., 2006; Uhde and Salthammer, 2007). Certain conditions in the distribution devices (e.g., elevated temperature, or the storage of concentrated liquids under oxygen contact for long periods of time) will also increase the possibility of not only the fragrance substances, but also degradation products being present in the air.