Final answer:
The airflow in the preparation and packaging area must be maintained at positive pressure to prevent contamination. Positive pressure is higher than atmospheric pressure, pushing air out whenever doors are opened, unlike negative or neutral pressures.
Step-by-step explanation:
For the preparation and packaging area, the airflow must be maintained at positive pressure. This is to ensure that any potential contaminants or particulates do not enter the space from surrounding areas. Positive pressure means that the air pressure inside the room is greater than the pressure outside, which helps to push air out of the room whenever doors are opened. In contrast, a negative pressure environment would pull outside air into the space, and neutral pressure would not effectively prevent contamination because the pressure inside would be equal to atmospheric pressure.
Factors such as the intrapulmonary pressure and the behavior of gases under different pressure conditions help us to understand why maintaining a controlled pressure environment is crucial, especially in sensitive settings that require hygiene and sterility.