Particle Emissions from Laser Printers: Have They Decreased?

Our work a decade ago demonstrated that approximately 30% of the laser printers tested were high emitters of ultrafine particles (<0.1 mu m). To assess how emission levels of the current generation of printers compared to the earlier models, we investigated 297 printers comprising 138 models from 12 different manufacturers, with the measurements conducted in Brisbane, Australia, and Cassino, Italy. In addition to particle number (PN-the majority of which are ultrafine particles), some of the printers were also tested for the emissions of volatile organic compounds (VOC). Based on the ratios of, respectively, PN and VOC concentrations above the printer before and after test printing, the printers were divided into four classes of emitters: nonemitters and low, medium, and high emitters. Our study showed that although different printer models were investigated in Brisbane and in Cassino, the distributions according to emitter classes were similar for PN emissions, with a high percentage of nonemitters and low PN emitters. In Brisbane, there were also mainly nonemitters and low VOC emitters, with, however, a higher percentage of VOC than PN emitters. In general we found that the emission levels were not intrinsic characteristics of specific brands or models of the printers. Finally, compared to the situation before 2007, large commercial printers have improved in terms of particle emissions; however, there has not been an obvious improvement over desktop printers.