A study that suggested some laser printers could pose a health risk has been published in full, together with a list of the printers involved in the study.
Particle Emission Characteristics of Office Printers, a study by a team of researchers at the Queensland University of Technology, was published in the American Chemical Society's Environmental Science & Technology on Wednesday. The findings suggested that fine particles, particularly toner dust released by some laser printers, can have serious health implications for those working close to the printers.
When the story was originally reported, a full list of the printers involved in the study had not been made available.
However, the abstract of Wednesday's article reveals that the worst offenders are almost exclusively HP printers — although many HP printers were also found to be low emitters of the "submicrometre particles".
The study described as "high level emitters" any printer that produced a ratio greater than 10, when comparing the "submicrometre particle number concentration peak value" emitted by the printer with the general background concentration value.
These printers included the following: HP Color LaserJet 4650DN; HP Color LaserJet 5550DTN; HP Color LaserJet 8550N; HP LaserJet 1320N; HP LaserJet 2420DN; HP LaserJet 4250N; HP LaserJet 8150N; and Toshiba Studio 450.
The HP LaserJet 1020 and HP LaserJet 4200dtn were classed as "middle level emitters", with a ratio between 5.1 and 10 — although the 4200dtn was labelled as a possible high emitter, along with the LaserJet 8000DN.
The HP LaserJet 5 printer showed up in the results as both a non-emitter and a high emitter, prompting the academics to propose further investigation into this phenomenon.
"Many factors, such as printer model, printer age, cartridge model, and cartridge age may affect the particle emission process and all of these factors require further study," the report notes in its conclusions.
HP said on Wednesday that it was in the process of evaluating the report, but insisted that it "assesses its LaserJet printing systems, original HP print cartridges and papers for dust release and possible material emissions to ensure compliance with applicable international health and safety requirements."