What is ultrafine dust: formation, causes & effects
Ultrafine dust has no natural origin, but is man-made and arises, for example, during combustion processes or chemical reactions. The concentration of small particles in the air also increases during printing and copying.
Possible causes of ultrafine dust indoors:
- Exhaust gases from road and air traffic
- electronic devices such as laser printers
- Combustion of wood & biomass (fireplace, stove, candle soot)
How dangerous is ultrafine dust?
Ultrafine dust stands for the smallest particles with a size of less than 1 µm. For comparison: a hair has a thickness of about 60 µm. These tiny particles can float permanently in the air, i.e. they never fall to the ground on their own. Once the particles are in the air, you breathe them in continuously - due to their very small size, the particles then penetrate deep into the respiratory tract. In the process, they are overlooked by the natural cleansing cells of the immune system, so that the ultrafine particles can even penetrate membranes of alveoli as well as mucous membranes. Via the alveoli, they enter the bloodstream, and via the blood they reach all organs of the body. They thus advance much further into the organism than larger dust particles, which are often already filtered and excreted in the nose or lungs. This nanodust has a lasting effect on the cardiovascular system and causes minute inflammations. This can cause cardiac arrhythmias, lung diseases and strokes; the ongoing inflammation in the body also significantly increases the risk of cancer. Due to the high lung permeability of ultrafine particles, they are considered more harmful to health than fine dust particles.
Potential health effects from nanoparticles:
- Chronic lung diseases & respiratory infections
- increased likelihood of tumors in the lungs, brain and all other organs
- Stroke
- Heart disease
Further detailed information can be found in our separate article Health Hazard Ultrafine Dust & Nanoparticles.
particulates by laser printer & toner: Why does particulates arise during printing?
First, how does a laser printer work? A laser printer uses a PCR roller to generate static electricity on a rotating image drum or photoconductor drum - the surface is electrically charged. The laser beam then discharges certain areas. The toner powder later adheres to these and is fixed by heat. A negative of the printed image is created on the drum. When a laser printer prints one page, two billion fine dust particles are produced - for every single page.
Professor Dr. med. Helmut Greim, long-time chairman of the MAK Commission of the DFG, classifies toners as granular bio-resistant dusts (GBS) - i.e. they cannot be decomposed or neutralized by the body's own processes. GBS are also poorly soluble particles that can accumulate in the lungs and lead to chronic disease development with symptoms such as coughing, impaired lung function, and in more severe cases even destroyed alveoli and emphysema (irreversible overinflation of the alveoli).
What are toner dusts made of?
Toner is a powdery mixture of various components. Resin particles in particular (around 90 percent) ensure that the toner remains on the paper. Color pigments account for just five percent. The rest is made up of waxes, iron oxide and various heat-resistant agents.
Toner particles are created in a melting process that mixes and fuses the ingredients, mechanically crushes and sieves them. The final toner particle is less than 7 µm (microns) in size. Potentially toxic compounds may adhere to the surface of the toner particles, such as volatile organic compounds (VOCs), ethylbenzene, phenols, aldehydes or various carboxylic acids.
Investigations show that nano-scale pigments may be present in the toner dusts. Although these are incorporated in thermoplastics, they are released by electrical charging and thus enter the air we breathe. The release of particles takes place both during the heating phase and during printing.
air-Q Lab: How does air quality change when printing with a laser printer?
We were interested in how much particulates a printer produces. We therefore carried out a practical test with our air-Q air measuring device to determine how strong the effects on air quality are during operation.
Our experiment setup and execution: We measured the UTAX P-5030DN laser printer (Kyocera FS-4200DN) with our air-Q Pro in a practical test. The printer has the Blue Angel RAL-UZ 171 and therefore has a particle count limit. It is also equipped with sufficient toner. We placed both devices in a one cubic meter transparent box and closed it with a lid. We could not create a completely airtight room because of the printer cable. The test sequence shows both scenarios, both the development of the room air when the printer is switched on without printing and during printing. We monitored the air development during a 10-minute test run.
After turning on the device, we let the printer warm up for about three minutes before we started printing. After that, pages were printed for about 9 minutes before there was a short interruption for refilling the paper around 13:35. Shortly after, we started printing again for another minute. After this, the scheduled test run ended and we ended the experiment at 13:37 by turning off the printer.
Our results show that the particulates measured value increases both when printing and when the printing process is stopped, as it cleans itself after the ongoing operation. We also found that it is irrelevant for the measured value development whether only a few pages are printed or the printer is in continuous operation: The fine dust load increases.
At the beginning of the test in our air-Q Lab, the fine dust load in the box is 0 µg/m³. After just under two minutes of testing, the fine dust load reaches and exceeds the recommended limit value. After seven minutes, the measured value peaks at around 24 μg/m³ - an exceedance of 166 %. After switching off the printer, the values drop again quickly, but only reach the recommended limit of the Federal Environment Agency.
In addition to particulates , other pollutants are increasing, such as VOCs, nitrogen dioxide, and sulfur dioxide.
Immediately after switching on and after a longer off phase, we also noticed an EXTREME increase in fine dust (see graphic below). We are in contact with Kyocera about this, since this is inexplicable for us. Above all, it is extremely harmful to health. We were able to reproduce this in part, but not at this level. Our assumption: loose toner was shaken loose during transport or exchange of the toner cartridges and blown out of the device when it was switched on.
How to protect against particulates from toner & printer? Our air-Q tips
Isolate laser printers, prefer inkjet printers
Laser printers rely on a chemical-metal mixture for the entire process. Although there are modern laser printers that use fewer metals, other pollutants such as VOCs, PAHs, UFPs continue to be used for the printing process with the toner or are produced during the approx. 200 degree hot process and thus enter the air we breathe. Never operate laser printers (toner-based printing systems) without filters and place laser printers and copiers in separate rooms with self-sufficient supply and exhaust air! Make sure that these rooms are not coupled with a central air conditioning system for supply and exhaust air.
Print with ink rather than toner, if possible. For healthier indoor air, inkjet printing technology is recommended. Thanks to so-called Heat-Free Technology, the printers require up to 96% less consumables than laser printers. The large ink tanks of inkjet printing are also more sustainable and also prevent the ink from drying out.
Our recommendations for safe operation of laser printers/copiers:
- Use tested toners & printers/copiers as much as possible
- Replace older devices, if possible, with printers that have a test seal or use toners that are lower in pollutants
- Set up printer in continuous operation in separate rooms
- Regular maintenance & cleaning of the equipment
- Do not open print cartridges by force
Does it help to observe certificates?
Certificates for laser printers are: LGA - tested for harmful substances, Energy Star label EPEAT as well as BG Prüfzert or DGUV Test, which tests work equipment with regard to safety and health protection. There is also the Blue Angel certificate (currently DE-UZ 219) for printers, according to which particle pollution is limited to 350 million particles for 10 minutes of printing. However, many devices have probably been artificially slowed down so that they can obtain the certification via an eco mode. Moreover, it is not completely clear which emissions are tested during the award process.
Furthermore, Blauer Engel uses the particle counting method to assess printers. Measurements in μg/m³ are ineffective, however, because the ultrafine particles have a measurable, "huge" surface area but no weight. We therefore breathe in billions of particles, while the limit value for weight is never reached.
Another problem: Certification is not a must. Therefore, devices that do not achieve the Blue Angel can still be purchased - for example, at particularly low discounter prices. There is also no regulation for old devices regarding the useful life or an obligation for maintenance.
Air quality monitoring & regular ventilation
Test your printer! Check the development of the room air and the emergence of particulates during printing with the air-Q air measuring device - at home and in the office. This way you can quickly see if your printer is affected and can react, ventilate as needed and thus remove particulates as well as nanoparticles.
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