Head-space, small-chamber and in-vehicle tests for volatile organic compounds (VOCs) emitted from air fresheners for the Korean market Wan-Kuen Jo a, * , Jong-Hyo Lee a , Mo-Keun Kim b a Department of Environmental Engineering, Kyungpook National University, Daegu 702-701, Republic of Korea b National Environment and Health Research Institute of Kyungpook Province, Daegu 702-702, Republic of Korea Received 22 March 2007; received in revised form 9 August 2007; accepted 9 August 2007 Available online 21 September 2007 Abstract The present study investigated the emission characteristics of gel-type air fresheners (AFs), using head-space, small-chamber, and in-vehicle tests. Five toxic or hazardous analytes were found in the headspace phase of AFs (toluene, benzene, ethyl benzene, and m,p-xylene) at a frequency of more than 50%. Limonene and linalool, which are known to be unsaturated ozone-reactive VOCs, were detected at a frequency of 58 and 35%, respectively. The empirical model fitted well with the time-series concentrations in the chamber, thereby suggesting that the empirical model was suitable for testing emissions. Limonene exhibited the highest emission rate, followed by m,p-xylene, toluene, ethyl benzene, and benzene. For most target VOCs, higher air change per hour (ACH) levels exhibited increased emission rates. In contrast, higher ACH levels resulted in lower chamber concentrations. The mean concentration of limonene was sig- nificantly higher in passenger cars with an AF than without. For other target compounds, there were no significant differences between the two conditions tested. Consequently, it was suggested that unlike limonene, the emission strength for aromatic compounds identified in the chamber tests was not strong enough to elevate in-vehicle levels. Ó 2007 Elsevier Ltd. All rights reserved. Keywords: Emission rate; Gel-type; Time-series concentration; Empirical model 1. Introduction Previous studies have implicated several consumer prod- ucts as being sources of indoor air pollution (Habib et al., 2006; Singer et al., 2006; Su et al., 2007). AFs are widely used in homes and non-industrial work places to supply a pleasant odor and to counteract any offensive smells. AFs work by using a nerve-deadening chemical that interferes with the human sense of smell, coating the nasal passage with an oily film, masking an offending odor with a differ- ent odor, or by deactivating the odor (EHANS, 2004). Certain VOCs emitted from AFs such as ethanol, benzaldehyde, a-terpineol, and benzyl acetate showed toxic effects at dose levels between 9 and 14 mg/kg (Cooper et al., 1995), however, AFs emit significant amounts of VOCs when applied indoors (Salthammer, 1999; Zhu et al., 2001; Singer et al., 2006). Synthetic, chemical-based AFs contain a number of chemicals including carcinogens and sensitizers, possible reproductive toxins, and neurotoxins (EHANS, 2004). Moreover, unsaturated organic constitu- ents emitted from AFs produce secondary toxic pollutants via reactions with oxidants such as ozone, hydroxyl radi- cals, and nitrogen oxides (Weschler and Shields, 1999; Atkinson and Arey, 2003). The characterization of emissions for household prod- ucts can provide valuable information in estimating expo- sure to these compounds and in the selection of safer consumer products. Although this kind of survey that is associated with the use of AFs has been conducted by research groups (Salthammer, 1999; Zhu et al., 2001; 0045-6535/$ - see front matter Ó 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.chemosphere.2007.08.021 * Corresponding author. Tel.: +82 53 950 6584; fax: +82 53 950 6579. E-mail address: wkjo@knu.ac.kr (W.-K. Jo). www.elsevier.com/locate/chemosphere Available online at www.sciencedirect.com Chemosphere 70 (2008) 1827–1834