The Question posed on LinkedIn.
Avoiding cross-contamination when using microbiological air-samplers is a key activity. But how effective is the procedure? To evaluate this, Tim Sandle and Ravikrishna Satyada have written a paper based on test data…link to Disinfection of active-air samplers.
For filling rooms, I’d always use a double wrapped autoclaved sampling head. For ancillary rooms where the risk to the product was lower, IPA was used rather than a new head.
With internal sanitation of air samplers, when I’ve validated units like the Merck MAS100 and Biomeriux RSC+, spraying with IPA was shown to be sufficient.
With regards of HEPA filtering the output airflow, smoke pencil studies showed laminar flow would take the air to the floor. Correct placement of the air samplers within the filling space and ensuring only samplers assigned to critical filling areas were used in critical filling areas would reduce the risk of cross contamination.
Good that you data showed effective sanitation and a lack (or low) cross contamination risk.