Use of a real-time microbial air sampler for operational cleanroom monitoring

PDA J Pharm Sci Technol. 2014 Mar-Apr;68(2):172-84. doi: 10.5731/pdajpst.2014.00952.


A sampler that detects and counts viable particles in the air of cleanrooms in real-time was studied. It was found that when the sampler was used to monitor airborne particles dispersed from a number of materials used in cleanrooms, including garments, gloves, and skin, the number of viable particles dispersed from these materials was greater than anticipated. It was concluded that a substantial proportion of these viables were of a non-microbiological origin. When the sampler was used to monitor a non-unidirectional airflow cleanroom occupied by personnel wearing cleanroom garments, it was found that the airborne viable concentrations were unrealistically high and variable in comparison to microbe-carrying particles simultaneously measured with efficient microbial air samplers. These results confirmed previously reported ones obtained from a different real-time sampler. When the real-time sampler was used in a workstation within the same cleanroom, the recorded viables gave results that suggest that the sampler may provide an effective airborne monitoring method, but more investigations are required.

Lay abstract: The airborne concentrations measured by a real-time microbial air sampler within an operational, non-unidirectional airflow cleanroom were found to be unrealistically high due to a substantial numbers of particles of non-microbiological origin. These particles, which resulted in false-positive microbial counts, were found to be associated with a number of materials used in cleanrooms. When the sampler was used within a cleanroom workstation, the counts appeared to be more realistic and suggest that this type of real-time airborne microbial counter may provide a useful monitoring method in such workstations, but further investigations are required.

Keywords: Airborne microbial contamination; Andersen sampler; Cleanroom; Real-time microbial air sampler.

MeSH terms

  • Air Microbiology*
  • Environment, Controlled*
  • Environmental Monitoring / instrumentation*
  • Environmental Monitoring / methods
  • Equipment Design
  • False Positive Reactions
  • Microbiological Techniques / instrumentation*
  • Particle Size
  • Particulate Matter / analysis*
  • Reproducibility of Results
  • Time Factors


  • Particulate Matter