Potentially hazardous particles emitted from common laser printers have been identified by an Australian university and other researchers.
The research, carried out at Queensland University of Technology, studied earlier findings that almost one-third of popular laser printers emitted large numbers of ultrafine particles.
The tiny particles are potentially dangerous to health because they can penetrate deep into the lungs.
The study found that ultrafine particles were formed from vapours produced when the printed image is fused to the paper.
In the printing process the printer toner is melted, and when it is hot certain compounds evaporate creating vapours. They then nucleate or condense in the air, forming ultrafine particles.
The particles are formed from both the paper and the hot toner. The hotter the printer gets, the greater the chance of the particles forming, the study said.
The study compared a high-emitting printer with a low-emitting printer.
Lower heat emission printers with efficient and regular temperature controls release fewer particles.
Sudden increases in temperature can add to the problem of particles being released, the university found.