- designed as airlocks
- effective flushing with filtered air
- separate rooms for entry and exit desirable
- hand washing facilities
- interlocking system for doors
- visual and/or audible warning system
Use filtered air supply to maintain pressure cascade
Pressure differential approximately 10 to 15 Pascals
Zone of greatest risk - immediate environment
Entry to all processing areas should be through airlocks. For personnel, these airlocks generally take the form of changing rooms that have a variable number of interconnecting rooms, depending on the grade of the area. Ideally, separate airlocks should ideally be provided for the entry of materials into the area. Airlocks should be flushed with filtered air. In some facilities, there are different airlocks for entry to and exit from manufacturing areas. This can promote unidirectional flow of personnel and material. Hand washing facilities should only be provided in change rooms, and not in production areas.
Filtered air should be supplied to the areas and in such a manner, that the pressure cascade is maintained. There should normally be a pressure differential of 10 to 15 Pascal between areas of lower and higher risk.
The supply of suitable quality air to sterile manufacturing areas, is very important. Filtered air under positive pressure should be supplied to production areas of sterile products. Verify whether the manufacturer has validation data of aspects relating to airflow patterns, and warning systems indicating failure of air supply (e.g. manometers measuring pressure differentials, or an audible alarm).Check the configuration and maintenance of HVAC and filters.
The pressure differentials between areas should be monitored and recorded in accordance with written SOPs.
(Note: Trainers should explain with the aid of a flip chart and drawings, suitable layout of premises, indicating air supply and return to areas, desired air flow patterns, design and purpose of air locks, and the concept of pressure differentials between different areas).