Safe laser printers and copiers

Modern office workflows would be difficult to imagine without laser printers and copiers. This makes it all the more important to use low-pollution types. Some laser printers emit only very low levels of contaminants. IFA has tested a number of these units. A list of tested "low-emission" equipment can be found on the Blue Angel website.

Notes on the state of the discussion

Although low-emission models are now available, laser printers continue to be criticized as a major source of pollutants. Some of the information published and linked in this context is apt to give rise to untenable conclusions. A number of toner powders for example have been found to contain benzene; benzene is a carcinogenic substance; it is therefore inferred that printer emissions are carcinogenic.

The public discussion was revived again in March 2010 by a report, appearing in virtually all media stating that a research team had suc-ceeded in detecting injury to human lung cells caused by printer emissions. Industry, however, is still waiting for a comprehensible scientific publication of this finding. For the time being, such reports therefore should not serve as a basis for re-evaluation of the emissions from printers and photocopiers.

The results of years of research and the findings of several test institutes including IFA are all too often neglected. The most recent major study was presented by the German Federal Institute for Risk Assessment (BfR) in the spring of 2008 (in German). It was based upon measurements of dust and organic substance concentrations in a large number of offices and on examinations of office workers who, in some cases, claimed to be suffering from "health impairments due to toner dust exposure". The pilot study failed to establish any clear corre-lation between laser printer emissions and the disorders reported; the authors do, however, recognize a need for further research. The German Social Accident Insurance has therefore issued a call for tenders for a corresponding research project. In this project, a medical trial is to be conducted with regards to the incidence of harmful effects upon human health resulting from exposure to toner dusts or arising during photocopying and printing processes.

It is frequently suggested that laser printers be retrofitted with filters in order to reduce their emissions. Retrofit filters are generally fitted to the printer by means of adhesive strips on the air vents where they are able to reduce particle emissions. However, most printers possess several vents, and all have a paper discharge tray. The IFA has found paper discharge trays to be a major source of particle emissions. By their nature, they cannot be closed off by means of a filter, so that this portion of emissions therefore cannot be covered by retrofit filters.

The German Federal Environment Agency has examined the suitability of retrofit filters for the filtering of ultrafine particles, and has concluded that filters cannot be recommended without reservation. "Retrofit filters do not provide a blanket solution to the problem of particle emissions from printers." The type of filter used must be considered very carefully, since not all filters are effective. "In addition, the recommendations for users of suitable filter types for particular printers have to date been inadequate in some cases."

IFA studies and comments

The studies conducted by IFA to date have focused on substances released by the printing system, consisting of printer, toner and paper. These emissions include dust, ozone and organic compounds such as benzene and styrene. It was found that advanced laser printers which passed the test to RAL UZ 122 released emissions only in very small amounts. In particular, it emerged that:

• No toner dust was detectable;
• Other organic substances, including benzene, were released only in very small quantities;
• Ozone emission levels were extremely low (some laser printers and copiers even use ozone-free technology)

These results are also summarized in the list of tested machines on the "Blue Angel" website (RAL-UZ 122, in German). All tested models which have passed this test appear in this list.

Apart from emissions which may occur during printing, care should be taken during replacement of toner cartridges and installation of the machine at its site. Before a toner cartridge is changed, the Guide notes regarding operation, cleaning and maintenance should be read. A description of how laser printers can be operated safely is given in BGI 820 (in German).

A printer shared by several office staff members and set up next to a workplace may disrupt their work. The actual need for a workplace printer should therefore be considered, as should the alternative of a central workgroup printer. The latter may induce workers to move around more often, thus activating their blood circulation and counteracting monotonous physical strain at the workplace.