A laser printer isn't really that different from that new Xerox at Sterling Cooper; toner sticks to a charged medium (a selenium drum in the 914) is transferred to the paper and baked on.
Last year Warren reported on an Australian study claiming that Some Laser Printers are as Bad as Secondhand Smoke; now a new Austrian study commissioned by the industry confirms that laser printers do emit ozone, volatile organic compounds and particles. Sort of.
inside a laser printer from How Stuff Works
Last year's study was controversial, and found that:
Certain laser printers used in offices and homes release tiny particles of toner-like material into the air that people can inhale deep into lungs where they may pose a health hazard...Lidia Morawska, Ph.D., and colleagues in Australia classified 17 out of 62 printers in the study as 'high particle emitters' because they released such elevated quantities of particles, which the researchers believe to be toner, the ultrafine powder used in laser printers instead of ink to form text and images. One of the printers released particles into an experimental chamber at a rate comparable to the particle emissions from cigarette smoking.
Needless to say, Hewlett Packard (which made the worst offenders) ridiculed the study then, saying:
HP does not see an association between printer use by customers and negative health effects for volatile organic compounds, ozone or dust. While we recognize ultrafine, fine, and coarse particles are emitted from printing systems, these levels are consistently below recognized occupational exposure limits.
However, the new study does appear to confirm the findings. According to TG Daily:
Fraunhofer-Gesellschaft, a German research company that just completed a study on laser printer emissions, reports that volatile organic-chemical emissions (ozone), silicon oil, paraffin and ultra-fine particles are emitted during laser printing.
However, when you read the Fraunhofer-Gesellschaft press release, it is not so clear; they say that they found such particles but claim that they are not necessarily any different than you might get from making toast.
The cause is the fixing unit — a component that heats up as high as 220Â°C during the printing process in order to fix the toner particles on the paper," explains WKI scientist Dr. Michael Wensing. The high temperatures cause volatile substances such as paraffins and silicon oils to evaporate, and these accumulate as ulta-fine particles. The scientists from Braunschweig observed similar phenomena — the formation of ultra-fine particles of volatile organic substances when heated — during typical household activities such as cooking, baking, or making toast.
So no doubt Hewlett Packard will tout this new report has proving that laser printing is no more dangerous than cooking. However, we don't recommend cooking without an exhaust fan over the stove, and it might be appropriate to consider proper ventilation in your home office as well (see Planet Green on home office dangers) and striving minimize your printing or go paperless.
Findings from the 2007 Australian study: (pdf of study here)
More in TreeHugger on the paperless or paper-reduced office:
Working From Home Makes More Sense Than Ever
The Paperless Home
Xambox Scans And Files
Print Less: Make Just One Copy Do the Job
Greenprint: Software that Saves