You should also check whether the manufacturer uses conveyer belts that pass through a clean and dirty area, to convey components or products. This can only be allowed if the conveyer belt is sterilised before moving into the clean area.

Equipment for use in the sterile area should be designed so that it can be operated with the minimum of personnel interference, thus reducing the possibility of contaminating the product. It should also be easily sterilized by moist or dry heat sterilization.

Sterilizers should be designed with a door at each end (known as double door autoclaves or double- ended autoclaves) to eliminate the possibility of mixing up sterile and non-sterile materials. This is particularly important for sterilizing components that are going into the filling room. They are loaded in the preparation area and unloaded in the sterile area, although preferably in a buffer room rather than directly in the filling room.

It is important that the zone in which the product is to be exposed is protected to the maximum extent possible. This requires the installation of laminar airflow cabinets over the piece of equipment, to ensure a supply of filtered air flowing with positive pressure towards the surrounding areas.

It is also necessary to ensure that the locations of the equipment and the operator do not cause a risk to the product by interrupting the flow of filtered air.

Where possible, maintenance and repairs of equipment should take place outside the area. However, if this is impossible, it should be done when there is no work going on and should be followed by a complete clean down and disinfection. Tools for such work should be sterilized before being taken into the area. It is even better if a full set of sterilized tools can be stored in the area specifically for this purpose. After maintenance has been completed, there should be a documented procedure for obtaining approval to resume operations in the area.

It is permissible to have transport systems to take product from the filling room to the sterilization/finishing area, but there must be a physical barrier across the actual interface between the two areas.