Laser Printers Particles Emissions Revisited

More than a decade ago, we encountered a problem of high particle concentrations in large open-plan offices when conducting investigations on the impact of a nearby motorway on air quality in the offices. Eventually the particles were linked to the operation of numerous laser printers in the offices and we designed a study to characterize and classify the printers according to their impacts as particle emitters (He et al 2007). We demonstrated that the particles were in the ultrafine range, and our subsequent studies showed that they were secondary liquid particles formed from volatile compounds emitted during the printing process (Morawska et al 2009), and that the operating temperature the printer was the key factor in this process (He et al 2010). Ten years later, we decided to revisit the issue and examine whether the new generation of printers is improved and emit less.