"We do not believe there is a link between printer emissions and any public health risk," the company said in a statement.
On Wednesday, researchers at Queensland University of Technology in Brisbane, Australia, published a paper detailing emission measurements of 58 laser printers inside a typical office. Emissions, believed to be related to the ultrafine powdered toner used in the printers, were tracked and the printers ranked as non-, low-, medium- or high-emitters. HP's models dominated the last category, accounting for 90 percent of the printers classified as emitting high levels of particulates.
"HP does not see an association between printer use by customers and negative health effects for volatile organic compounds, ozone or dust," the company continued in its statement. "While we recognize ultrafine, fine, and coarse particles are emitted from printing systems, these levels are consistently below recognized occupational exposure limits."
Researchers at Lawrence Berkeley National Laboratory, a U.S. Department of Energy lab in Berkeley, Calif., agreed that it's too early to draw a line between printer emissions and health dangers.
"What we don't know is what the findings in the study mean," said Rich Sextro, an environment scientist at Berkeley Lab, in a posting on the laboratory's Web site. "Certainly our expectation is that exposures to lots of ultrafine particles probably isn't a very good thing, but we have no idea at the moment what that translates into in the real world."
The Australian study is among the first to document emissions from laser printers, but the specifics of how printers produce particles and what those particles are made of is mostly unknown -- something HP emphasized. "Testing of ultrafine particles is a very new scientific discipline," the company said. "Currently, the nature and chemical composition of such particles, whether from a laser printer or from a toaster, cannot be accurately characterized."
One thing that everyone agreed on -- even the Australian researchers -- is that more study should be done. Until a definitive link between laser printers, particulates and health risks are made, "fine particles alone are not enough to worry about," said Tom McKone, another Berkeley Lab scientist.