Standard for compressed air testing of medical devices

Analysis of Compressed Air Quality Testing Standards for Medical Devices

compressed air used in the field of medical devices is directly related to patient safety and product quality, and its testing must strictly follow the specific standards of the medical industry. Now on the test items, technical requirements and implementation specifications for professional description:

1. core detection index system
according to the Guidelines for Inspection Points of Process Gas for Medical Devices and ISO 15867 standard, the compressed air of medical devices shall meet the following four types of inspection requirements:

1. microbial limit
   • suspension bacteria: ≤ 1CFU/m & sup3;(gas for clean area)
   • sedimentation bacteria: ≤ 0.2CFU/dish (& phi;90mm Petri dish exposed for 1 hour)
   • endotoxin: ≤ 0.25EU/m & sup3;(gas path in direct contact with liquid medicine or blood)
2. particulate matter content
   • particle size range: 0.1-5μm particles to be tested in all items
   • quantity Restrictions:
     • ≥ 0.5μm particles ≤ 3,520 particles/m & sup3;(equivalent to ISO Class 5 cleanliness)
     • particles ≥ 5μm ≤ 20 particles/m & sup3;
3. physical and chemical pollutants
   • oil content: ≤ 0.01 mg/m & sup3;(detected by total carbon analyzer)
   • moisture content dew point:-40 ℃ (equivalent to ≤ 0.07 g/m & sup3; absolute moisture content)
   • carbon Monoxide: ≤ 0.5ppm (direct acting gas source ≤ 0.1ppm)
4. pressure stability
   • fluctuation range: ≤ ± 0.02MPa (gas for key treatment equipment)
   • flow characteristics: Instantaneous flow change ≤ 10% of rated flow (e. g. ventilator air supply)

2. detection method and frequency

1. microbiological detection
   • sampling method: Use Anderson percussive sampler, flow rate 28.3L/min, sampling time ≥ 2 minutes
   • culture condition: Tryptic soy peptone agar medium, 30-35 ℃ for 5 days
   • detection frequency daily detection in high-risk areas and weekly detection in ordinary areas
2. particulate Matter Detection
   • instrument Requirements laser particle counter with resolution up to 0.1μm
   • sampling Point sampling at 15-30cm downstream of gas supply terminal
   • detection frequency: Test after each sterilization, and retest the whole item every month.
3. Physical and chemical testing
   • oil content infrared spectrophotometry, detection wavelength 2930cm-& sup1;
   • dew point temperature capacitive humidity sensor, accuracy ± 1 ℃
   • detection frequency daily detection of continuous operation equipment and weekly detection of standby equipment

3. quality risk control

1. system Validation
   • DQ/IQ/OQ/PQ four-phase verification is required for new or modified systems
   • URS documentation for key parameters (e. g. filter efficiency, pipe cleanliness)
2. daily monitoring
   • set up an online monitoring terminal in the gas supply network to display pressure, temperature and dew point data in real time.
   • Establish a trend analysis system to automatically warn when 3 consecutive data points are close to the warning limit.
3. Emergency treatment
   • configuration of standby air compressor unit and terminal filter device, switching time ≤ 30 seconds
   • development of microbial contamination emergency plan, including system disinfection, product isolation and other 7 measures

4. industry application practice
typical medical equipment enterprise compressed air detection scheme:

• ventilator production line: 0.22μm sterilization filter is configured, and TSA medium is used for terminal bacterial content detection.
• blood analyzer: Set up an activated carbon adsorption tower, and control the total hydrocarbon content below 0.05ppm
• aseptic packaging equipment: VHP space sterilization, compressed air contact surface ethylene oxide residue ≤ 1ppm

enterprises should establish compressed air quality files to record inspection data, maintenance records, deviation treatment and other information. Through the implementation of FMEA (Failure Mode and Effects Analysis), 15 types of potential risk points are identified, and targeted control measures are formulated to ensure that the compressed air quality continues to meet the requirements of medical device production.