Laser Printers and the Problems They Cause in the Indoor Environment

Health effects associated with laser printers
Pollutants emitted by laser printers
Minimizing the health effects from laser printers

Hazards Associated With Laser Printers

Operating equipment such as computers, laser printers, and photocopiers has been associated with building-related symptoms and health effects due to the release of chemical gases and particles. These emissions can result from the inks and toners, papers, carbonless paper, coatings on transparencies, glue on adhesive labels, the mechanical print process, plastic construction materials, circuit boards, and residual cleaning chemicals. Many of these chemicals will decrease with usage of the product such as computers. Others are the result of the mechanical operation and will always be there when the machine is operating. Laser printers in particular have been associated with^1,2:

• Headaches

• Mucous membrane irritation

• Dryness of the throat, eyes and nose

Pollutants Emitted by Laser Printers

• VOCs: Laser printers and photocopiers have been shown to emit volatile organic compounds (VOCs), such as aldehydes, styrene, xylenes, ethylbenzene and hydrocarbons, many resulting from the inks and toners. Computers, in contrast, often release chemicals with strong odors such as phenol and plasticizers.

• Particulates: Particulates are released by an operating machine. They may result from paper debris, toners, and inks. Many of these particles are in the respirable size and some agencies are concerned about the presence of carbon black.

• Ozone: Laser printers create ozone through their "corona wires" that apply a charge to the paper so the ink will cling to it. However, newer models use a different system to reduce the amount of ozone produced by the printer. Concentrations of ozone in a room where laser printers are being used can exceed the currently regulated standard for ozone in the outdoor air. Ozone is a strong lung irritant. Many machines have filters to extract the ozone emissions.

• Formaldehyde: Formaldehyde is commonly emitted. It may be associated with papers and coatings on papers or as a constituent of inks and toners.

Minimizing Health Effects From Laser Printers

• Choose low-emission machines: Buy printers that can do the print job while contributing minimal emissions to the air. These printers have been designed to emit little chemical and particle emissions while operating. For more information, see www.greenguard.org.

• Ozone filters: Make sure that the laser printer has an ozone filter. Some of the newer models come with them. Ozone from laser printers is removed by activated charcoal filters that are replaced after a certain number of printed pages. These filters can reduce the average ozone levels from 430 µg/min to 100 µg/min.³ The filters need to be replaced according to the manufacturers instructions.

• Ventilation: Large numbers of printers and photocopiers should be put together and isolated in a separate area with their own ventilation system that is exhausted to the outside. This area must have a lot of outdoor air and the air should not be recirculated throughout the rest of the building. Machines should not be located near return air ducts and should be turned off when not in use for any length of time. New machines need to be operated as much as possible with good ventilation during the first two weeks of purchase. Many of the new chemicals and odors will emit during this period, but they will decrease with time. An initial "burn in" with good ventilation will help reduce the odors and occupant irritation.

• Selection of media: Select papers that do not have formaldehyde treatments and coatings. Avoid the use of carbonless paper, if possible, unless it is known to be free of chemical emissions while being used. Avoid printing of labels with adhesive. If required, ensure that good ventilation is supplied. Make sure that paper is compatible and recommended by the manufacturer of the equipment.

References

1. Wolkoff P, Wilkins CK, Clausen PA, Larsen K. Comparison of volatile organic compounds from processed paper and toners from office copiers and printers. Indoor Air 1993; 3:113-123.

2. Skoner DP, Hodgson MD, Doyle WJ. Laser printer rhinitis. NE J Med. 1990; 322(18):1323.

3. Hetes R, Moore M, Northelm C. Office equipment: Design, indoor air emissions, and pollution prevention opportunities. US EPA Project Summary, EPA/600/SR-95/045; Research Triangle Park, North Carolina. 1995.