Characterization of particle emission from laser printers

Area of Science:

• Environmental Health
• Indoor Air Quality
• Occupational Health

Background:

• Laser printers are common in offices and emit fine particles.
• Exposure to these particles raises concerns about potential health impacts on employees.

Purpose of the Study:

• To analyze particle emission characteristics of 110 laser printers.
• To estimate emission rates (number, surface area, mass) and particle size distributions.
• To evaluate employee exposure to laser printer emissions in typical and severe office conditions.

Main Methods:

• Measurements of particle concentrations and size distributions from 110 laser printers in a chamber.
• Calculation of emission rates in terms of particle number, surface area, and mass.
• Estimation of daily surface area doses for office employees under various printing scenarios.

Main Results:

• Emission rates varied widely: number (3.39×10^8–1.61×10^12 part/min), surface area (1.06–1.46×10^3 mm^2/min), and mass (0.132–123 μg/min).
• Median particle size was 34 nm.
• Typical office exposure resulted in a low daily surface area dose (2.7 mm^2), but severe conditions (e.g., poor ventilation, high printing frequency) led to significantly higher doses.

Conclusions:

• Laser printer particle emissions are measurable and variable.
• Under typical conditions, the estimated exposure dose for office workers is relatively low.
• However, specific environmental and operational factors can substantially elevate particle exposure, warranting consideration for indoor air quality management.