5. Pass Box
The Pass Box is a device placed on the wall of the clean room compartment. Its function is to serve as s buffer zone for the transfer of goods in different levels, and it can also ensure that the goods are transported in a controlled enviroment without contamination. When transferring items, the airflow and pressure of the clean room may be destroyed due to the opening of the door. Therefore, the doors on both sides of the transfer box should have interlocking controls that cannot be opened at the same time to prevent cross contamination.