Silent Menace Ozone is a gas, produced when oxygen meets a high-voltage electrical charge, like those produced in laser printers. You may have noticed its sharp metallic odor around an old electric motor that's sparking brightly. In smaller concentrations, most people may be unable to detect the presence of the gas.
Ozone is bad news.
Anything over a few tenths of a part per million can cause nausea, headaches, fatigue, dryness in throat, eyes, and other mucous membranes. British and Danish scientists studied offices containing copiers and laser printers, and discovered ozone concentrations 10 times over what's considered safe. The risk seems greatest in poorly ventilated areas. Apple Computer and Hewlett-Packard , both major manufacturers of laser printers, recommend ozone filter replacement. Ozone trapped inside the toner cartridge can destroy the charge generation and transfer layers, as well as the polymeric coating on the drum surface.