The Hazards of Toner Particles

Studies investigating the effects of toner particles on human health have varied in their conclusions, but all agree the topic needs more study. Laser printers are standard for most large offices. Three studies from 2007 to 2010 illustrate the focus of current research. While one draws a direct link between toner exposure and reduced lung function in mice, another finds no correlation between increased death rates and toner exposure in human workers. A ground-breaking Australian study from 2007 showed microscopic toner particles released by printers can be inhaled deeply into the lungs.

Toner Use and Indoor Air Quality

• An Australian study in 2007 concluded that laser printers used in homes and offices release very small particles of toner into the air and can be inhaled deeply into the lungs, posing a potential health risk. The study was conducted by the International Laboratory for Air Quality and Health in Brisbane, Australia, at the Queensland University of Technology. The study tested popular models under the Canon, HP Color Laserjet, Ricoh and Toshiba brand names. Seventeen were labeled "high particle emitters."

  An additional phase of the study looked at particle emission characteristics of three different laser printers. The study concluded emissions are printer-type specific and affected by toner coverage and the age of the cartridge. One printer released particles into an experimental chamber at a rate comparable to the particle emissions from cigarette smoking, according to the report. Health effects from these microscopic particles can range from respiratory irritation to more serious illnesses including cardiovascular disease and cancer, according to Lidia Morawska, one of the authors of the study, and warranted further study.

Mortality Rates of Exposed Employees

• A study published in the Journal of Occupational & Environmental Medicine in October 2010 measured the mortality rates of employees exposed to toner over time and concluded there was no evidence that toner exposure increased the risk of death from any cause, or from any of the 23 specific causes of death analyzed. The study looked at 33,671 employees of a xerographic workplace who worked between 1960 and 1982 in manufacturing or servicing. Scientists tracked their vital status through 1999 and calculated standardized mortality ratios using the U.S. population for comparison. The study reported results consistent with general mortality patterns among healthy working populations.

Lung Responses in Mice After Toner Exposure

• A study published in September 2010 concluded that exposure to toner particles can inhibit the normal growth of mice and also cause a significant inflammatory response with lesions in the lung tissue. A toner suspension was instilled into the lungs of male mice four times on alternating days and scientists monitored the response of the lungs at intervals. The study was conducted by CAS Key Lab for Biological Effects of Nanomaterials and Nanosafety, at the National Center for Nanoscience and Technology in Beijing, China. Scientists concluded further study was vital to evaluate the potential health effects on humans of such exposure.