title: Ozone-initiated particle formation, particle aging, and precursors in a laser printer.
abstract: An increasing number of researchers have hypothesized that ozone may be involved in the particle formation processes that occur during printing, however no studies have investigated this further. In the current study, this hypothesis was tested in a chamber study by adding supplemental ozone to the chamber after a print job without measurable ozone emissions. Subsequent particle number concentration and size distribution measurements showed that new particles were formed minutes after the addition of ozone. The results demonstrated that ozone did react with printer-generated volatile organic compounds (VOCs) to form secondary organic aerosols (SOAs). The hypothesis was further confirmed by the observation of correlations among VOCs, ozone, and particles concentrations during a print job with measurable ozone emissions. The potential particle precursors were identified by a number of furnace tests, which suggested that squalene and styrene were the most likely SOA precursors with respect to ozone. Overall, this study significantly improved scientific understanding of the formation mechanisms of printer-generated particles, and highlighted the possible SOA formation potential of unsaturated nonterpene organic compounds by ozone-initiated reactions in the indoor environment.
authors.affiliation: International Laboratory for Air Quality and Health, Institute of Health and Biomedical Innovation, Queensland University of Technology, GPO Box 2434, Brisbane QLD, 4001, Australia.
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.forename: Congrong
authors.initials: C
authors.lastname: He
authors.forename: Lidia
authors.initials: L
authors.lastname: Morawska
authors.forename: Peter
authors.initials: P
authors.lastname: McGarry
authors.forename: Graham
authors.initials: G
authors.lastname: Johnson
mesh_terms: D016902:Air Pollution, Indoor; D007834:Lasers; D015394:Molecular Structure; D010126:Ozone / Q000737:chemistry*; D010209:Paper; D052638:Particulate Matter / Q000737:chemistry*; D011327:Printing / Q000295:instrumentation*
chemical_list: D052638:Particulate Matter; D010126:Ozone