The aim of thisresearch project was to understand particle sizes and the rates ofparticle generation forrepresentative processes in pharmaceutical and biotechnologicalcleanrooms. This was achievedvia field measurements and data collection in severalpharmaceutical and biotechnologycleanrooms. Field measurements were performed usingcertified and calibratedparticle counters and airflow meters. The airflow data, particle data,and cleanroom air conditionswere recorded for both ‘operational’ and ‘at rest’ conditionsto deduce the particlegeneration rate.