How is unidirectional air verified in the Primary Engineering Controls (PEC)?

Unidirectional airflow in Primary Engineering Controls (PEC) is crucial for maintaining a sterile environment during compounding. This type of airflow ensures that air flows in a single direction, minimizing the risk of contamination from particles and microbes.

The verification of unidirectional air is effectively accomplished through a smoke study. In this procedure, a visible smoke source is introduced into the airflow within the PEC. The behavior of the smoke is observed; it should demonstrate a consistent, straight-line movement that aligns with the intended airflow patterns of the system. This visual evidence confirms that there are no backflows or turbulence that could compromise the sterile environment.

While visual inspection and observing airflow patterns may provide some insights into airflow, they do not offer the definitive confirmation needed to ensure that the airflow is unidirectional. Similarly, an air quality meter measures the levels of airborne contaminants but does not directly verify the directional nature of the airflow. Therefore, a smoke study remains the standard practice for confirming the effectiveness of unidirectional airflow in PECs.