Toner-based printers

Main article: Laser printer
Toner-based printers work using the Xerographic principle that is at work in most photocopiers: by adhering toner to a light-sensitive print drum, then using static electricity to transfer the toner to the printing medium to which it is fused with heat and pressure.
The most common type of toner-based printer is the laser printer, which uses precision lasers to cause adherence. Laser printers are known for high quality prints, good print speed, and a low (Black and White) cost-per-copy; they are the most common printer for many general-purpose office applications. They are far less commonly used as consumer printers due to a high initial cost.
Laser printers are available in both color and monochrome varieties.
Another toner based printer is the LED printer which uses an array of LEDs instead of a laser to cause toner adhesion to the print drum.
Recent research has also indicated that Laser printers emit potentially dangerous ultrafine particles, possibly causing health problems associated with respiration [1] and cause pollution equivalent to cigarettes.[2] The degree of particle emissions varies with age, model and design of each printer but is generally proportional to the amount of toner required. Furthermore, a well ventilated workspace would allow such ultrafine particles to disperse thus reducing the health side effects.