Office Laser Printers: Nanoparticles Warning from Toxicologists
SafeWork Australia commissioned the Queensland University of Technology and Toxikos Pty Ltd to conduct a study on workplace exposure to laser printer toxic emissions. The study was aimed to provide guidance on control measures and thus reduce exposure levels. This likewise evaluated the adverse health effects associated with exposure to laser printer emissions in the workplace.
Laser printer emission components are much different to toner particles as well as air pollution particles. Emissions from laser printers are mainly aerosol condensates of volatile organic compounds (VOCs) or semi-volatile organic compounds (SVOCs). Possible negative health effects were traced to the chemical nature of the aerosol and not the physical properties of the “particulate” if the emission is VOC or SVOC in nature. The emissions will disintegrate and will be absorbed, once it comes into contact with the respiratory tissue.
The scientific research commenced the test experiment by comparing levels of exposure to laser printer emissions at approximately 1 metre from the printer. For each assessment, there is a “risk of direct toxicity” that is reported. Airborne particles that scatter within an office environment combine with other particles from different sources like paper fibres, inorganic gases and organic vapours. Particles that accumulate outside the office like those of vehicle emissions that flow into the building may further aggravate the emissions being inhaled by workers, apart from the laser printer emissions.
The comprehensive study also revealed that potential health effects from particles in laser printer emissions can aggravate one’s health and this is coined as “sick building syndrome.” It can be associated with other factors like poor indoor air quality and particulate ambient air pollution. Pulmonary inflammation and fibrosis can adversely victimise the workers as proven by these toxicological experiments. A study of 1,016 adults showed (including 346 office workers) symptoms of sick building syndrome and exposure to fumes from printer and copier emissions, paper dust, and carbonless copy paper. All reported general symptoms of headache and fatigue.
A patient was studied and the diagnosis showed that the patient has been suffering weight loss, abdominal pains and diarrhea. An electron microscopy X-ray analysis revealed some “submesothelial carbon aggregates” consisting of nanoparticles or simply black spots found in the patient’s peritoneum. These nanoparticles were later identified as having the same size as reported to be emitted from printers. It was documented in many occupational health literatures that handling toners could be associated with respiratory health effects, thoracic radiological abnormalities and in some cases pneumonitis. Since the patient had a laser printer on her work desk for three years the authors assumed that the patient had been exposed to toner dust.
Identification of particles from experiments using printers that were modified to operate without paper revealed that particles were emitted from high boiling point siloxanes and other SVOCs derived from chemicals that are related to thermo-protection of plastics. Highly saturated water vapour released from paper could form a “condensate” which is harmful to one’s health. Dimethyl and disobutyl succinonitrile were also discovered in the laser printer emissions aside from the common VOCs like styrene, xylene, ethylbenzene and toulene.