Toner is mainly used in laser printers, photocopiers and fax machines. Some of the powders released when using toner may cause irritation and, with exposure to extreme amounts, even constitute a health hazard. Research has proven, however, that low concentrations of the powder do not pose a health risk.
Toner powder is a mixture of a number of very fine particles:
- resin particles to melt the toner and bind it to the paper;
- carbon black;
- colour pigments;
- magnetizable metal oxides to generate an electrostatic charge.
Threshold limits (the so-called MAC values) have been determined for hazardous materials, defining the maximum allowable concentration of such substances in parts per million of air. Standards like the MAC values may not be exceeded. However, the MAC values of these substances could be exceeded through intensive use of badly maintained equipment or use of the equipment in small, poorly ventilated spaces. Maintenance and replacement of parts like internal filters reduce emissions and are therefore by regulation to take place regularly.
Hazardous materials include:
- nitrogen dioxide (NO2);
- toner powder (particulates, carbon blacks), which may include heavy metal particles (mercury, cobalt, nickel);
- chlorized carbon compounds;
- paper dust;
- volatile organic substances like benzene, styrene and toluene;
- ozone (O3): prevalent mainly in older equipment, less so in more modern machines.
Photocopiers, fax machines and laser printers are more of a health risk at the office when multiple machines are placed next to each other or if it concerns mid-to-high-volume machines.
Laser printers and photocopiers are classified as one of the following volume categories:
- low-volume: less than 5,000 print-outs per month;
- can be placed in a workroom, but place as far from the workplace as possible
- mid-volume: more than 5,000 but less than 50,000 print-outs per month;
- need to be placed in a separate space or well-ventilated hallway
- high-volume: more than 50,000 print-outs per month;
- need to be placed in a separate printing room with a dedicated exhaust
- Another possibility is to use an inkjet printer instead of a laser printer.
Recommendations for toner replacement
Current printer toners are almost fully closed systems (cartridges), resulting in a very slight chance of being exposed to toner powder when replacing the cartridge. However, this does not apply to toner containers for photocopiers and suchlike.
The following recommendations apply when replacing such containers:
- never replace the container with your bare hands. Wear disposable gloves and, preferably, a disposable industrial mask;
- wrap the toner container in a plastic bag and dispose of it as a hazardous material.