Emissions of air pollutants from scented candles burning in a test chamber Marco Derudi a , Simone Gelosa a , Andrea Sliepcevich a , Andrea Cattaneo b , Renato Rota a , Domenico Cavallo c , Giuseppe Nano a, * a Politecnico di Milano, Dipartimento di Chimica, Materiali e Ingegneria Chimica “G. Natta”, Via Mancinelli 7, 20131 Milano, Italy b Università degli Studi di Milano, Dipartimento di Medicina del Lavoro, Via San Barnaba 8, 20122 Milano, Italy c Università degli Studi dell’Insubria, Dipartimento di Scienze Chimiche ed Ambientali, Via Lucini 3, 22100 Como, Italy article info Article history: Received 18 January 2012 Received in revised form 4 March 2012 Accepted 9 March 2012 Keywords: Scented candles Emission factors Test chamber Volatile organic compounds PAHs abstract Burning of scented candles in indoor environment can release a large number of toxic chemicals. However, in spite of the large market penetration of scented candles, very few works investigated their organic pollutants emissions. This paper investigates volatile organic compounds emissions, with particular reference to the priority indoor pollutants identified by the European Commission, from the burning of scented candles in a laboratory-scale test chamber. It has been found that BTEX and PAHs emission factors show large differences among different candles, possibly due to the raw paraffinic material used, while aldehydes emission factors seem more related to the presence of additives. This clearly evidences the need for simple and cheap methodologies to measure the emission factors of commercial candles in order to foresee the expected pollutant concentration in a given indoor envi- ronment and compare it with health safety standards. Ó 2012 Elsevier Ltd. All rights reserved. 1. Introduction Indoor air quality is affected by a number of indoor and outdoor pollutants sources. However, while several information are avail- able for outdoor pollutant sources in terms of emission factors (Ravindra et al., 2008; Estrellan and Iino, 2010), only few infor- mation have been published for indoor pollutant sources (Ott and Siegmann, 2006; Sarigiannis et al., 2011), which include tobacco smoke, as well as cooking, heating, and office equipments (e.g., Tuckett et al., 1998; Long et al., 2000; Fan and Zhang, 2001; Destaillats et al., 2008). Burning of candles in indoor environments can release a large number of toxic chemicals, including acetaldehyde, formaldehyde, acrolein, and polycyclic aromatic hydrocarbons (Lau et al., 1997; USEPA, 2001; Lee and Wang, 2006; Orecchio, 2011). It is believed that regular burning of several candles in indoor environments can expose people to harmful amounts of organic chemicals (USEPA, 2001). Among the huge variety of candles available on the market, scented candles have gained popularity over the past 30 years resulting in the current abundance of candle shops and aroma- therapy candle products. For the sake of example, U.S. retail sales of candles are estimated at approximately $2 billion annually, being by far the fragrance the most important characteristic impacting candle purchases. In spite of this large penetration of scented candles in indoor environments, a few works investigating pollutants emissions from candle burning (van Alphen, 1999; Fine et al., 1999; Nriagu and Kim, 2000; Guo et al., 2000; Wasson et al., 2002; He et al., 2004; Zai et al., 2006; Lee and Wang, 2006; Pagels et al., 2009) were mainly focused on metals and soot emissions rather than on organic pollutants, such as Volatile Organic Compounds (VOC) or PAHs (Lau et al., 1997; Maupetit and Squinazi, 2009; Orecchio, 2011). However, candle composition is expected to determine the pollutants emissions, possibly leading to important emissions of VOC. Moreover, the priority indoor pollutants identified by the European Commission (EU) mainly refer to VOC (Kotzias et al., 2005). Consequently, the aim of this work has been to characterize pollutants emissions from the burning of scented candles using a test chamber. In particular, emission factors for some polycyclic aromatic hydrocarbons (PAHs), aromatic species (BTEX) and some short chain aldehydes have been measured for different scented candles. Among the others, formaldehyde, benzene and naphtha- lene (which are classified by the EU as “High priority chemicals”) as well as toluene and xylenes (which are classified by the EU as “Second priority chemicals”) have been investigated. The obtained results have been compared with the few data available in the * Corresponding author. Tel.: þ39 0223993134; fax: þ39 0223993180. E-mail address: giuseppe.nano@polimi.it (G. Nano). Contents lists available at SciVerse ScienceDirect Atmospheric Environment journal homepage: www.elsevier.com/locate/atmosenv 1352-2310/$ e see front matter Ó 2012 Elsevier Ltd. All rights reserved. doi:10.1016/j.atmosenv.2012.03.027 Atmospheric Environment 55 (2012) 257e262