First air - Aseptic last line of defence

The principle of ‘First Air’ relates to the dynamic and fragile environment of Grade A enclosures. First Air refers to the undisturbed, unidirectional air from the HEPA filter source that impacts open product. This acts as the final line of defence to protect the product.

First air principles become compromised if the operator invades the unidirectional airflow. For example, by reaching over open vials, or similar inappropriate behaviour. Actions like these could contaminate the product.

Maintenance of the integrity of First Air must be assured.

But, how can you maintain the principles of First Air if you can’t see wind?

To visualise the movement of air, we incorporate neutrally buoyant tracer particles into the airflow during qualification. We do this to ensure we characterise and track airflow patterns within the critical Grade A environment. This process is Smoke or Airflow Visualisation. It has many applications within critical Grade A qualification and validation processes.

Helping operators to interact compliantly

One emerging use of Smoke visualisation is to fine tune aseptic behaviours as part of Aseptic training. This allows the Operator to demonstrate they can interact with the product safely, without breaking first air principles. Such visualisation enables operators to adapt their technique where necessary. Ensuring continued compliance to good aseptic technique.

To underpin the importance of Airflow visualisation, Draft Annex 1 2020 (v12) (item 7.19) now specifically references Airflow visualisation to be incorporated into aseptic operator training programs.

Recognition of smoke visualisation’s importance and the impact onto First Air is concurrent with the strong regulatory drive to exclude humans altogether from the process.

Stable Grade A environments

The panacea for Aseptic processing would be a perfectly stable and predictable humanless Grade A environment. Where airflows remain uninterrupted and the vagaries of human behaviours are completely eliminated.

 

 

You can read our previous two articles around Aseptic practices below:

Aseptic Techniques Prevent Contamination

Aseptic Behaviours in the Real World