Laser printers may cause harm by emitting concentrations

An Australian research team has found that laser printers give off invisible particles as they operate, with the worst culprit emitting concentrations similar to those of second-hand tobacco smoke.
Researchers acknowledge the conclusions are based on a small subset of data and raise many more questions than answers. Independent experts and a printer manufacturer agree, saying it would be premature to issue any warnings until researchers knew exactly what chemicals make up the ultra-fine particles.
Even so, it would not hurt to make sure printers are kept in open areas at a distance from users, said research member Lidia Morawska, a physicist with Queensland University of Technology in Brisbane, Australia. "This information should mainly guide manufacturers into designing printers that are low emitters," Morawska said. "In the meantime, if you can, put the printer in a separate well-ventilated area."
It is not clear that these ultra-fine emissions are dangerous, according to Robert Hamers, the chairman of the chemistry department at the University of Wisconsin-Madison.
Each particle, up to 1,000 times smaller than a dust particle, is small enough that it can get drawn deeply into the lung's tiny sacs, Hamers said, but what it does once it gets there depends on its chemical composition.
For example, cigarette smoke is dangerous not because it contains tiny particles but because those particles include cyanide and carbon monoxide.
"Yes, printers generate particles, but probably much less chemically toxic than cigarette smoke," Hamers said. "Until those particles can be analysed, people ought not to overreact," he added.
Tuan Tran, vice-president of sales and marketing for HP's imaging division, said the company puts its printers through rigorous emissions testing. He said HP is trying to contact the researchers for clarification on their conclusions, some of which he said seemed odd.
For example, the Australian team found that one HP printer produced high emissions while a nearly identical model produced none. "We want to make sure we have the facts before we jump to conclusions," Tran said, adding: "We do quite a bit of work to make sure our products adhere to health standards around the world."
Experts noted that the types of particles identified by the researchers can also be generated from simple activities such as burning a candle or making toast.