In a properly controlled cleanroom, there are specified limits for the concentration of airborne particles which must be continually removed from the air. Those particles might be created by the workers, the equipment, the process, or the facility itself.
Air filtration and flow is critical to avoid cleanroom contamination. In order to visualize the room’s air flow and to comply with ISO Class 5 specifications, airflow visualization studies, also known as smoke studies, are performed to ensure that the airflow is exiting through the cleanroom HEPA filters
in a single direction. In case of contamination, the smoke studies offer visual verification of where the contaminant would move within the room.