The high voltage corona in a photocopier or laser printer is switched on only during part of each copy cycle. For a typical office machine usage, the total energized time is usually less than 60 minutes per day. The COSHH regulations give an Occupational Exposure Standard of 0.1 PPM for the air breathed by each person, averaged over an eight hour day.
Océ policy is to test machines at some three times the intended use and to ensure that the Ozone concentration at the operator position remains below the odour perception level in a room of minimum recommended size with natural ventilation. This gives confidence that, when used in the manner intended, the Ozone level remains well below the level required by COSHH and thus does not represent a hazard to health.
A study some years ago in Denmark highlighted 3 factors that should be borne in mind:
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Desktop laser printers are often placed alongside a personal computer and are close to the operator's face. If they are in a confined space and used at high copy output throughout the day, then the Ozone concentration reaching the operator may be significant. It is desirable to ensure reasonable ventilation around desktop computer systems. |
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It is preferable not to sit immediately behind a copier or laser printer that is used frequently during the day because the Ozone emitted may not have decomposed or diluted sufficiently before reaching you. In any case, the dry warm air exhausted by the machine may cause throat discomfort. Place machines against a wall, or position a screen between the copier and adjacent desks. |
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Ozone filters are catalytic converters using activated charcoal. They have an indefinite life but it is possible for the pores in the granules to become blocked by toner or paper dust. All Océ machines using the patented Océ Copy Press system have large capacity Ozone filters. The Danish University tested Océ machine filters which had made several million copies and confirmed that they continued to be effective. Much depends on the machine design and the quality of the copy paper. Océ machines have airflows controlled so that contamination of the filters is minimised. | |
