Exposure to particles from laser printers operating within office workplaces

Area of Science:

• Environmental Science
• Occupational Health
• Aerosol Science

Background:

• Limited understanding of laser printer particle exposure for office workers.
• Need to assess impact on indoor particle number concentration (PNC) and worker exposure.
• Investigate the role of office ventilation in particle transport and concentration.

Purpose of the Study:

• Quantify the impact of laser printer operation on office background PNC.
• Determine airborne particle exposure levels for office workers near printers.
• Evaluate the influence of ventilation on particle distribution.
• Assess the need for particle control strategies.
• Identify relevant instrumentation for particle characterization.

Main Methods:

• Experimental measurement of temporal and spatial PNC.
• Operation of 107 laser printers in open-plan offices across five buildings.
• 8-hour time-weighted average exposure assessment.
• Analysis of particle size distribution, predominantly ultrafine (<100 nm).

Main Results:

• Printer particle exposure significantly less than background on average, but peak exposures can be >100 times higher.
• Ultrafine particles (<100 nm) are the predominant emission.
• Significant variation in non-printer derived particle concentrations among offices.
• Proposed peak particle reference value of 2.0 × 10(4) particles cm(-3).

Conclusions:

• Laser printer operation can lead to significant, albeit often transient, increases in airborne ultrafine particles.
• Office ventilation plays a role in particle transport and concentration.
• Control of both printer-derived and background particles is recommended.
• Introduction of peak particle reference values is proposed for occupational exposure assessment.