Standard Operating Procedures (SOP) and Maintenance Guidelines for Cleanroom Pass Boxes
Overview and Purpose
As an essential auxiliary device for cleanrooms, the Pass Box is primarily used for transferring small items between:
- Clean areas of different grades.
- Non-clean areas and clean areas.
The core objective is to reduce the frequency of door openings in the cleanroom, thereby minimizing cross-contamination and maintaining the integrity of the controlled environment.
Operating Procedures & Methods
1. Interlocking Mechanism Operation All pass boxes are equipped with an interlocking device (Mechanical or Electronic). This ensures that only one door can be opened at any given time.
- Step 1: Open the entry door (Note: the door will not open if the opposite door is not fully closed).
- Step 2: Place the materials into the pass box.
- Step 3: Close the entry door securely.
- Step 4: The operator on the receiving side opens the exit door, retrieves the materials, and closes the door.
2. Cleanliness Management Level The pass box must be managed according to the higher cleanliness level of the two connected areas.
- Example: A pass box connecting a coding room and a filling room must follow the stringent management requirements of the filling room.
3. Post-Shift Sanitation At the end of each work shift, the cleanroom operator is responsible for:
- Wiping all internal surfaces of the pass box clean.
- Activating the UV Sterilization Lamp for at least 30 minutes.
4. Material Preparation When moving materials from a lower-grade area to a higher-grade cleanroom, the surface of the materials must be thoroughly cleaned/disinfected before being placed in the pass box.
5. UV Lamp Maintenance Regularly inspect the working condition of the internal UV lamp. The UV tubes must be replaced periodically to ensure effective sterilization performance.
Safety & Maintenance Precautions
- Avoid Forcible Entry: If a door cannot be opened smoothly, it is usually because the door on the opposite side is not fully closed or the interlocking system is engaged. Never attempt to force the door open, as this will permanently damage the interlocking mechanism.
- Emergency Repair: If the interlocking device fails to function normally, stop using the pass box immediately and contact maintenance for repairs.
- Strict Storage Policy: The pass box is for transfer purposes only. It is strictly forbidden to store any materials, debris, or unauthorized items inside the chamber.
- Defined Responsibility: Management of the pass box is generally the responsibility of trained cleanroom operators.
