Editing Laser printing (section)

===Ozone hazards===
As a normal part of the printing process, the high voltages inside the printer can produce a [[corona discharge]] that generates a small amount of ionized oxygen and nitrogen, which react to form [[ozone]] and [[nitrogen oxides]]. In larger commercial printers and copiers, an [[activated carbon]] filter in the air exhaust stream breaks down{{citation needed|date=September 2011}} these noxious gases to prevent pollution of the office environment.

However, some ozone escapes the filtering process in commercial printers, and ozone filters are not used at all in most smaller home printers. When a laser printer or copier is operated for a long period of time in a small, poorly ventilated space, these gases can build up to levels at which the odor of ozone or irritation may be noticed. A potential health hazard is theoretically possible in extreme cases.<ref>{{cite web |title=Photocopiers and Laser Printers Health Hazards |url=http://www.docs.csg.ed.ac.uk/Safety/general/photocopiers.pdf |date=2010-04-19 |website=www.docs.csg.ed.ac.uk |access-date=2013-10-22 |archive-date=2013-07-11 |archive-url=https://web.archive.org/web/20130711191442/http://www.docs.csg.ed.ac.uk/Safety/general/photocopiers.pdf }}</ref>