Laser printer dust isn't from the toner

According to a research report, the fine particulates released by laser printers do not come from the toner. Investigations carried out by the Fraunhofer-Gesellschaft's Wilhelm-Klauditz-Institut (WKI) in collaboration with the Queensland University of Technology (QUT) in Australia, show the repeatedly detected ultra fine particles consist of volatile organic compounds. Tunga Salthammer, who heads the responsible department at the WKI, noted that "A significant property of these ultra fine particles is their volatility, which suggests that we are not talking about toner particles,".

The suspicion that the fine particles, which were first detected in 2006, are something other than toner particles has been around for a while. The German Federal Institute for Risk Assessment (BfR) announced last year that the particles measured in the course of its toner study are "with a probability bordering on certainty" not toner particles. This suspicion was further underlined by tests using modified printers lacking toner and paper, which demonstrated the same effects. This hinted at the conclusion, now reached by the Fraunhofer researchers, that the emissions originate from the printer unit itself.

According to the researchers, the high temperatures generated cause evaporation of volatile substances such as paraffins and silicone oils, which consolidate into nano-particles. The researchers also observed similar phenomena involving the formation of ultra fine particles from volatile organic compounds through heating, while performing typical domestic activities, such as cooking, baking or making toast.

Because the ratio of the mass of the emitted particles to their number is very low, the researchers had to develop special procedures for studying them. They were then able to measure and compare the volume, size and chemical composition of the emitted particles. The Fraunhofer-Gesellschaft notes that it received support in the form of expertise and finance from printer and copier manufacturers through Bitkom.

Achim Stelting, chairman of the organisation – nano-Control, criticised the fact that the effect on people exposed to these emissions, has still not been determined. According to Stelting, the effect of toner particles on workers who are exposed to them on a daily basis, also requires further research. The current investigations show that although there is no exposure to toner particles during normal printer operation, it is a different matter for staff such as maintenance technicians, who work in professions in which they are confronted with toner particles on a daily basis.

The German Bundestag's parliamentary environment committee plans to look at the potential health risks from laser printers in a meeting with experts in late January initiated by the Green party. Insiders expect the Ministry for the Environment will by then have made available further research material on the effects on people, via the former head of the toner study, clinician Volker Mersch-Sundermann.

(trk)