Continuous Air Microbial Monitoring

This is what is written in the GMP Annex 1 at the Chapter n.9. 9.24 Continuous viable air monitoring in grade A (e.g. air sampling or settle plates) should be undertaken for the full duration of critical processing, including equipment (aseptic set-up) assembly and critical processing. A similar approach should be considered for grade B cleanrooms based on the risk of impact on the aseptic processing. The monitoring should be performed in such a way that all interventions, transient events and any system deterioration would be captured and any risk caused by interventions of the monitoring operations is avoided.

The culture agar medium is progressively dehydrated and it loses the nutrient characteristics for specific nutrients for different micro-organisms. The consequence is that the microorganisms can have difficult to multiplicate and the risk is the difficulty to have the correct colonies count.

It is necessary to adopt an air sampler with a lower air flow rate (e.g.: 25 l/m) and to adopt Petri dishes with at least a volume of 30 ml of culture agar medium.

Several are the reasons.

1. It is possible to divide the working shift time in different periods and in case of microbial contamination, it is possible to identify when the fact happened.
2. The operator handles the air sampler only at the beginning and at the end of activity and therefore the time is reduced with less possibility of contamination.
3. The adoption of the air sampler with satellites gives the possibility to monitor different risk positions.

The suggested air sampler is the “funnel” model because the housing of the culture plate is outside from the isolator and therefore the space is saved and the handling with the isolator gloves is eliminated.

It depends how long is the working shift. Up to four hours the 2 aspirating heads model is o.k. With longer time, the 3 aspirating heads are suggested.

The adoption of the sterile “Daily Shift” irradiated certified and triple packed for use in critical cleanroom, RABS and Isolators aspirating heads allows a full traceability throughout the whole supply chain. The certification of sterility simplifies the activity of the laboratory and is convenient for the document inspection.

The calculation of cleaning, packaging for autoclaving, sterilisation process, certificate of sterilisation, storage of documentation, risk of un-correct certification, paper working confirm the advantage of the adoption of “Daily Shift” aspirating head.
They furthermore allow time saving during periods of unusually heavy workloads.

The transparency of the “Daily Shift” gives the possibility to the operator to control the presence of the culture agar plate.

The result of counted cfu of a reference micro-organism on TSA culture plate, with and without the aspiration cycle are compared to validate the same results (with a statistical microbial contest).

It is requested the traditional annual control.

The final cost of the membrane filter or other “closed” system is higher in comparison with a normal culture agar plate as used with the TRIO.BAS. This is an important fact to consider when you take the decision to invest money for the continuous monitoring air sampler.

Yes, using the photo-camera, in combination with the BAS software, the image of culture plate is stored for evaluation and printing.