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Member Research & Reports

Member Research & Reports

Harvard: Laser Printing has Gone ‘Nano’ — but is it Safe?

Manufacturers of toner used in consumer laser printers and other printing equipment are incorporating engineered “nano” materials into their formulations to improve quality. It’s a trend seen in a wide range of products from cosmetics to building materials, but the new technology is raising safety concerns. These tiny particles — less than 100 nanometers (billionths of a meter) — are able to reach deep into the lungs when inhaled, potentially causing respiratory and cardiovascular damage.

Sandra printer

[Photo: Researcher Dr. Sandra V. Pirela demonstrates the exposure generation system used to monitor and assess printer emissions during use]

Researchers at Harvard T.H. Chan School of Public Health’s Center for Nanotechnology and Nanotoxicology recently assessed 11 common laser printers to see if they emitted nanoparticles during use, and if these particles are harmful. The Center examines the potential risks and benefits of nanoparticles used by a variety of industries, hoping to develop a greater understanding of how they interact with the body and the environment — and to provide evidence that will encourage the burgeoning nanotechnology industry to develop in a responsible manner.

“With so many products going nano, safety assessments are needed to safeguard public health,” said center director Dr. Philip Demokritou, associate professor of aerosol physics. “There is a lack of data on the potential release of these nanomaterials into the air during consumer use, and their possible environmental health hazards.”

For the printer study, the researchers developed an exposure generation system to monitor and assess emissions during use. As toners don’t list the presence of nanoparticles on the product labels, the first step was to confirm that they were indeed present in formulations currently on the market. When tests proved positive, the researchers hit “print” and measured what came out. The results were surprising. They discovered that some printers release particles at concentrations comparable to highly polluted highways.

Further experiments in Dr. Demokritou’s lab found that exposure to the particles elicited an array of unfavorable biological responses at the cellular level, including those linked to the development of respiratory and cardiovascular diseases.

But that doesn’t mean that people should stop printing — just that minimizing exposure to nanoparticle emissions during printing might be a good idea. Dr. Demokritou and colleagues recommend that laser printers be placed in well-ventilated areas, and that users leave the room during large print jobs. Read more