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It seems that ultrafine dust from laser printers and photocopiers does not contain toner particles

18/2007, 16.10.2007

Final report on the pilot study expected towards the end of the year

A pilot study was launched mid-2005 designed, amongst other things, to identify possible indications of links between emissions from laser printers and photocopiers and adverse health effects in exposed office workers. The study was conducted by the Institute for Indoor and Environmental Toxicology of Gießen University Clinic on behalf of the Federal Institute for Risk Assessment (BfR). Between January and October 2006 indoor air was measured in 63 offices and 69 of the people who worked there were examined. The study results for most of the technical indoor air and medical parameters did not attract attention. This applied to temperature, air humidity, volatile organic compounds, volatile organic individual substances, mould concentrations as well as to the allergic and inflammatory parameters of the test persons. However, the proportion of physical disorders which could not be explained medically was higher in the workers examined than in the control group. Some of the persons examined reacted hypersensitively to bronchial irritation. When the appliances were switched on, the contamination of the offices with fine and ultrafine dust increased considerably. It would seem that most of the ultrafine particles measured were not toner particles. This was the conclusion reached by scanning and transmission electron microscopy tests. "The pilot study does not provide any definitive answer as to whether the increase in this dust in the offices could have a health impact", commented BfR President Dr. Dr. Andreas Hensel. "Anyone who uses laser printers and photocopiers should reduce his exposure to fine and ultrafine dust". The Federal Institute for Occupational Safety and Health (BAuA) in Dortmund has published practical tips for employees as well as for employers.

BfR launched the study after doctors reported health disorders in patients who attributed them to the use of laser printers and photocopiers, mostly at the workplace. The main symptoms described were ocular irritation, disorders of the respiratory tract and pharyngeal mucosal irritation. Following coordination with the interest group of toner damage sufferers (ITG), the Director of the Institute for Indoor and Environmental Toxicology at Gießen University, Professor Dr. Volker Mersch-Sundermann, was asked to carry out the study. The human medical tests were conducted by Professor Caroline Herr at the Institute for Hygiene and Environmental Medicine at Gießen University.

The study was designed as a feasibility study. It was to focus in particular on the following questions:

  • Are the study methods and design suitable for replying to the question in a scientifically sound manner?

  • Does the operation of laser printers and photocopiers influence indoor air quality?

  • Are there signs of an association between the emissions from the office equipment and adverse health effects/damage in the exposed office workers?

In the course of the study indoor air was measured in 63 offices in nine office buildings at four locations in Germany. Equipment emissions were measured whilst switched off, whilst switched on and during printing. 69 test persons were examined clinically and interviewed. BfR provided information on the intermediate results on its website. BfR passed on the draft final report for comments to various experts who discussed it today at BfR. The final version should be ready by the end of the year and, like the intermediate reports, will also be posted on the Internet. The following results of the pilot study can already be summarised:

As long as the group of test persons is sufficiently large, the methods and study design used seem to be suitable for providing sound scientific answers to the questions raised.

When the laser printers and photocopiers are switched on, the concentration of fine and ultrafine particles in the indoor air increases significantly. But the concentration of ultrafine particles then falls during printing. Apparently, most of these particles are not toner material. The exact composition of the particles has not yet been fully clarified.

Only weak associations can be established between the emissions from the office equipment and adverse health effects in office workers. Neither the inflammation parameters nor the sensitisation rates were higher in the persons examined than in the average population. The persons examined did, however, suffer on average more frequently from disorders which could be classified under the sick building syndrome like, for instance, irritative mucosal disorders.

At the present time, it is not possible to give a definitive answer to the question whether the emissions from office equipment can cause health disorders. BfR advises placing laser printers and photocopiers that are used frequently and to print a large volume of pages in separate rooms with good air circulation. The leaflet "Photocopiers and Printers in the Office" (in German) contains practical tips for individual precautionary measures. It is published by the Federal Institute for Occupational Safety and Health (BAuA) in Dortmund.

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