Indoor Fine Particles: The Role of Terpene Emissions from Consumer Products

Abstract

Consumer products can emit significant quantities of terpenes, which can react with ozone (O3). Resulting byproducts include compounds with low vapor pressures that contribute to the growth of secondary organic aerosols (SOAs). The focus of this study was to evaluate the potential for SOA growth, in the presence of O3, following the use of a lime-scented liquid air freshener, a pine-scented solid air freshener, a lemon-scented general-purpose cleaner, a wood floor cleaner, and a perfume. Two chamber experiments were performed for each of these five terpene-containing agents, one at an elevated O3 concentration and-the other at a lower O3 concentration. Particle number and mass concentrations increased and O3 concentrations decreased during each experiment. Experiments with terpene-based air fresheners produced the highest increases in particle number and mass concentrations. The results of this study clearly demonstrate that homogeneous reactions between O3 and terpenes from various consumer products can lead to increases in fine particle mass concentrations when these products are used indoors. Particle increases can occur during periods of elevated outdoor O3 concentrations or indoor O3 generation, coupled with elevated terpene releases. Human exposure to fine particles can be reduced by minimizing indoor terpene concentrations or O3 concentrations.

Unambiguous identification of esters as oligomers in secondary organic aerosol formed from cyclohexene and cyclohexene/α-pinene ozonolysis

“…The special scientific interest about the atmospheric chemistry of these natural alkenes is mainly due to the tremendous amounts emitted globally from tropical, temperate or boreal forests. However, also indoor air can contain considerable amounts of terpenes, emitted from furniture, solvents or air fresheners (Baumann et al, 1999;Hodgson et al, 2002;Sarwar et al, 2004). The gas phase reactions of these alkenes with reactive atmospheric species (ozone, OH-radicals, NO 3 -radicals) lead to the formation of products with lower vapour pressures.…”

Secondary organic aerosol from ozone-initiated reactions with terpene-rich household products

“…Terpenes and ozone are commonly present indoors, and their reactions can produce particles (Weschler and Shields, 1999;Long et al, 2000;Wainman et al, 2000;Sarwar et al, 2004;Liu et al, 2004). Consumer products, such as cleaning agents and air fresheners, are common sources of terpenes (Nazaroff and Weschler, 2004).…”

“…Several studies have measured SOA formation and growth from ozone reactions with pure terpenes or with terpenecontaining products under indoor-relevant conditions. Most of these studies measured particles using an optical particle counter (Weschler and Shields, 1999;Wainman et al, 2000;Weschler and Shields, 2003;Sarwar et al, 2003;Sarwar et al, 2004;Hubbard et al, 2005;Singer et al, 2006a). Optical particle counters (OPC) typically measure only particles that are 100 nm or larger and thus cannot characterize the ultrafine particles that are an essential component of particle nucleation and growth.…”

Particles in the Indoor Environment

“…The formation of SOAs through the reaction of ozone with terpenes and other unsaturated organic compounds was demonstrated and confirmed in many test chamber experiments (e.g. Wainman et al, 2000;Fan et al, 2003;Sarwar et al, 2004;Liu et al, 2004b;Vartiainen et al, 2006;Destaillats et al, 2006;Aoki & Tanabe, 2007). In two office rooms, for instance, there was an increase in the particle mass and the PNC (Fig.…”

“…This phenomenon was explained by referring to the new particle formation and / or particle growth through oxidative processes in the indoor environment. Other working groups, too, were able to detect in test chambers in the presence of ozone and the simultaneous application of terpene-containing cleaning agents a significant increase in particle number concentrations and the particle mass (Sarwar et al, 2004;Singer et al, 2006;Destaillats et al, 2006).…”