Internal Quality Control of Aseptic Rooms in Food Microbiology Labs

News 16 7 月, 2025

The aseptic room is the cornerstone for testing bacteria, yeast, mold, and various pathogenic microorganisms in food microbiology. Whether it meets sterile operational standards and has a sound internal quality control system directly impacts the accuracy of microbiological testing results.


1. Layout and Design of the Aseptic Room

The walls, floor, and ceiling must be smooth, easy to clean, impermeable, and resistant to disinfectants. The aseptic room should be completely sealed and maintain hygiene to prevent contaminants like dust and insects. Proper air filtration systems and transfer windows should be installed.

Common disinfectants (e.g., phenol solution, 75% ethanol, 0.1% benzalkonium chloride) must be readily available. The aseptic room should be located in a low-traffic area and have buffer zones for gowning and footwear changes.


2. Construction Materials

All materials must meet fire and environmental safety standards and be corrosion-resistant and easy to disinfect. Surfaces should be seamless and corners rounded to avoid dust accumulation. Doors must be tight-fitting and self-closing, with new materials used for insulation and hygiene control.


3. Environmental Monitoring and Air Purification

Environmental monitoring is essential for accurate results. Temperature (~22°C) and humidity (<65%) must be controlled. Advanced laminar flow purification systems ensure air cleanliness, temperature, humidity, and airflow. UV germicidal lamps and air showers reduce microbial contamination.

Monitoring for airborne particles and microorganisms should be routine. Settle plate methods (e.g., PCA and Bengal red agar) can help detect microbial load. If colonies exceed 3 CFU/plate, disinfection is required.


4. Personnel Practices and Operational Control

Before testing, the room should be UV-sterilized for at least 30 minutes. Personnel must follow strict hygiene protocols: handwashing, gowning, disinfection, and limited movement. Entry/exit should be minimized, and tools disinfected after use.


5. Use and Storage of Sterile Items

All equipment and media must be sterilized. Dry-heat sterilized items can last a month if properly stored; autoclaved media should be used within one week. Storage conditions affect shelf life—shorten it during humid or rainy periods.


6. Routine Management and Supervision

Avoid clutter to reduce contamination risk. Monitor and maintain UV lamps, air filters, and equipment regularly. Ill personnel should not enter the aseptic room. Dust levels can be measured with particle counters, and filter replacements should be scheduled annually.