This presentation will be a follow up to the former study on particle emissions from office laser printers (He et al., 2007, Morawska et al., 2009). Further investigations of the nature of printer-generated particles, their formation processes, as well as the main factors which affect the emissions have been conducted. This talk will provide information about the results of these investigations. BIO: Congrong He holds a BSc in Atmospheric Physics from Nanjing University, China, a MSc in Environmental Sciences from Murdoch University, Australia, and a PhD in Aerosol Sciences which he received from Queensland University of Technology, Australia in 2005. He has previously worked as a researcher at the Institute of Atmospheric Environment, Chinese Research Academy of Environmental Sciences, Beijing, China. The main areas of his previous research were atmospheric environmental capacity and planning, transport of acidic pollutants and transport of aerosol pollutants. His major research achievements during the past 15 years have been in the identifying, characterisation and quantification of biogenic VOCs emissions from Australian native plants, characterisation and quantification of indoor and outdoor aerosols, secondary organic aerosol (SOA) formation, indoor particle sources and indoor particle depositions.