Standardized Operating Procedures for Cleanroom Workbenches
Although the overall cleanroom environment meets standards, improper operation of the clean bench can still disrupt the local ultra-clean environment and cause contamination. Based on the characteristics of the cleanroom environment, standardized operating procedures for the entire experimental and production process have been developed, covering all stages: pre-operation, during operation, and post-operation.
(I) Pre-operation Preparation: Comprehensive Pre-treatment to Solidify the Cleanliness Foundation
1. Cleanroom Environment Confirmation: Confirm in advance that the cleanroom temperature, humidity, pressure differential, and cleanliness are within normal standards. Close unnecessary doors and windows to reduce air convection and prevent turbulent airflow from interfering with the laminar flow effect of the clean bench.
2. Equipment Pre-purification and Sterilization: Turn on the UV germicidal lamps on the clean bench 30 minutes in advance to sterilize the work surface, interior chambers, and ventilation channels comprehensively. After sterilization, turn off the UV lamps and run the fan unloaded for 10-15 minutes to thoroughly remove residual ozone and stabilize the internal laminar airflow. Operation is prohibited if the fan is not stable.
3. Deep Equipment Disinfection: Use 75% medical alcohol to wipe the workbench surface, inner walls, inside of sliding doors, and operating window frames in a unidirectional Z-shaped motion from the inside out. Avoid wiping back and forth to prevent secondary contamination. Allow to stand for the alcohol to completely evaporate and dry.
4. Material Disinfection and Placement: All consumables, instruments, reagents, and materials entering the workbench must be disinfected by wiping their outer walls with 75% alcohol beforehand. Strictly adhere to the zoning principle of clean on the left, operating in the center, and contaminated on the right. Clean materials and empty consumables are placed on the left, the core operating area is in the center, and waste is temporarily stored in sealed containers on the right. All materials must be kept away from air inlets and outlets and must not obstruct airflow.
5. Personnel Attire: Operators must strictly wear sterile clothing, caps, masks, and gloves specific to cleanrooms. Hair must be combed clean, and there should be no exposed skin or hair. After hand disinfection, hands should be slowly extended into the operating area.
(II) Standardized Operation: Controlling Airflow and Preventing Human-Induced Contamination
1. Strictly Control Equipment Opening and Closing Range: The opening height of the workbench sliding door should be strictly controlled between 15-20cm. A moderate opening range is crucial to avoid damaging the air curtain barrier and allowing unpurified air and suspended impurities to intrude, while ensuring sufficient operating space.
2. Standardize Operating Actions: Extend your arm vertically and slowly into the operating area. The entire operation should be gentle, steady, and slow. Avoid large swings, rapid hand movements, and frequent entry and exit from the operating opening to prevent disrupting laminar airflow, stirring up dust on the workbench, and damaging the local clean environment.
3. Strictly Adhere to Operating Prohibitions: The entire operation must be performed within the core clean area of the workbench. Touching the outside of windows, equipment walls, or other non-clean areas is prohibited. Open flames are strictly prohibited inside the workbench to avoid burning the filter element and disrupting airflow balance. Electrically heated sterile equipment can be used as an alternative. No materials should be piled or placed near the equipment vents.
4. Strict Zoning: Clean materials, samples to be processed, and waste materials must be stored in strictly separate zones, avoiding cross-contamination and haphazard stacking. Discarded nozzles, waste liquids, and residues must be promptly sealed and collected to prevent the spread of contaminants.
(III) Post-Operation Cleanup: Closed-Loop Cleaning and Long-Term Maintenance
1. Immediate Workbench Cleaning: After operation, immediately empty all samples, materials, and consumables from the workbench, thoroughly cleaning any residual waste liquids, residues, and debris to ensure the workbench is free of any debris.
2. Secondary Disinfection and Sterilization: Wipe the equipment workbench, inner walls, and operating tools again with 75% medical alcohol in one direction to completely remove residual microorganisms and trace contaminants, completing secondary disinfection.
3. Delayed Equipment Purification: Keep the fan running continuously for 10-15 minutes to thoroughly remove residual dust and contaminants from the cavity through clean laminar airflow. After the internal environment is completely purified, turn off the fan and lighting equipment. 4. Long-lasting sterilization and registration: After closing the sliding door, turn on the UV lamp for 30 minutes to complete the final sterilization of the cavity; after sterilization, turn off the UV lamp and register the equipment operation and usage status to complete the closed-loop operation.
In a cleanroom system, the clean bench is the core carrier for local high-precision cleanliness control. It not only supplements and upgrades the overall cleanliness of the workshop but also serves as a key line of defense to ensure high-precision processes, aseptic operations, and product quality. Standardized operating procedures are a prerequisite for the equipment to function effectively. Operators must strictly adhere to the full-process standards of pre-treatment, standardized operation during operation, and closed-loop maintenance afterward, avoiding operational errors and implementing regular maintenance to continuously and stably maintain a local ultra-clean environment, effectively avoid contamination risks, and ensure the efficient, compliant, and precise conduct of cleanroom production and experimental work.