Bio-Safety Cabinet Performance Qualification (PQ) is an important activity in pharmaceutical microbiology laboratories. It provides documented evidence that a Bio-Safety Cabinet (BSC) performs according to its intended design and approved operating requirements.
A Bio-Safety Cabinet provides a controlled working environment for handling biological materials that may present contamination or exposure risks. Its performance depends on effective airflow, suitable filtration, proper cabinet operation, and appropriate maintenance.
This guide explains the qualification process, including HEPA filter integrity testing, air velocity measurement, airflow visualization, non-viable particle counting, recovery testing, microbiological monitoring, illumination, noise measurement, and qualification documentation.
What is Bio-Safety Cabinet PQ?
Bio-Safety Cabinet Performance Qualification is the documented assessment of a cabinet’s ability to perform its intended functions under specified operating conditions.
The qualification confirms that the relevant performance parameters meet the approved acceptance criteria and that the cabinet is suitable for its intended laboratory application.
Depending on the cabinet type, manufacturer requirements, and intended use, the qualification may assess:
- HEPA filter integrity.
- Air velocity and airflow distribution.
- Airflow direction and containment characteristics.
- Non-viable airborne particle concentration, where applicable.
- Recovery performance, where applicable.
- Airborne or surface microbiological contamination, where required.
- Illumination inside the working chamber.
- Noise generated during operation.
The tests included in the qualification protocol should be selected according to the cabinet design, its intended biosafety function, applicable standards, and the manufacturer’s recommendations.
Purpose of Bio-Safety Cabinet PQ
The main objectives are to:
- Verify that the installed cabinet operates according to its approved specifications.
- Confirm the integrity of the installed HEPA filtration system.
- Evaluate airflow characteristics and their suitability for the intended work.
- Assess relevant environmental and operational parameters.
- Establish documented evidence of acceptable performance.
- Identify defects or deviations requiring corrective action.
- Support reliable laboratory operations and contamination control.
Bio-Safety Cabinet System Description
A typical Bio-Safety Cabinet may include the following components:
| Component | Function |
| Blower or fan | Produces the airflow required for cabinet operation. |
| HEPA filter | Removes airborne particles from the air passing through the filter. |
| Pre-filter | Captures larger airborne particles and helps protect downstream components where fitted. |
| Stainless steel work surface | Provides a cleanable working area for laboratory activities. |
| Front opening and sash | Provide operator access and form part of the cabinet’s airflow and containment design. |
| Airflow grilles | Direct air into the cabinet’s designed airflow pathway. |
| Control panel | Displays operating conditions and allows the user to control approved functions. |
| UV germicidal lamp, if fitted | Provides supplementary surface treatment when used according to the manufacturer’s instructions; it does not replace cleaning or disinfection. |
| Lighting system | Illuminates the working area. |
The exact configuration varies by cabinet type and manufacturer.
Important: A Bio-Safety Cabinet is not interchangeable with a clean bench or a conventional laminar airflow unit. The intended protection provided by each device differs. A qualification protocol must therefore be suitable for the specific cabinet type and its intended use.
Responsibilities During Bio Safety Cabinet PQ
The qualification should be performed by trained personnel under an approved protocol.
| Department | Responsibility |
| Quality Assurance (QA) | Prepare or coordinate the protocol and report, review documentation, assess deviations, and ensure compliance with the quality system. |
| Quality Control (QC) | Provide technical support and verify that the cabinet is suitable for its intended laboratory application. |
| Engineering | Support equipment identification, operating checks, maintenance requirements, and technical troubleshooting. |
| External qualification agency | Perform specialized measurements and tests when assigned, using suitable calibrated instruments and approved methods. |
| Qualification team | Coordinate activities, review observations, verify completion of required tests, and ensure traceable documentation. |
| Head of Quality or authorized approver | Review and approve the protocol and final report according to the site’s approval procedure. |
The specific allocation of responsibilities should be defined in the approved site procedure.
Training Requirements
Personnel involved in qualification should receive appropriate training before executing or reviewing the study.
Training should cover:
- The purpose and scope of cabinet qualification.
- The approved testing procedure.
- Instrument handling and calibration-status verification.
- Sampling and measurement locations.
- Documentation practices and data recording.
- Safety precautions during testing.
- Deviation reporting and investigation.
- Preparation and review of the qualification report.
Training records should be retained according to the site’s documentation requirements.
Pre-Qualification Requirements Bio-Safety Cabinet PQ
Before testing begins, verify that the necessary prerequisites have been completed.
Equipment and documentation checks
- Confirm the cabinet identification number, manufacturer, model, and location.
- Review the equipment specifications and manufacturer’s operating instructions.
- Confirm the availability of relevant installation, maintenance, and previous qualification records.
- Verify that the cabinet is installed in the intended location and is suitable for the intended application.
- Check that maintenance or repair activities affecting performance have been completed.
- Ensure that the cabinet is operating under the conditions specified in the approved protocol.
- Verify that all test instruments have valid calibration status.
- Confirm that personnel performing the tests are trained and authorized.
Instruments used for qualification
The instruments required depend on the tests included in the protocol.
| Instrument | Application |
| Anemometer | Measurement of air velocity. |
| Aerosol photometer and suitable aerosol generator | HEPA filter integrity testing using an approved aerosol challenge method. |
| Non-viable particle counter | Measurement of airborne particle concentrations where applicable. |
| Smoke generator or suitable airflow visualization equipment | Observation of airflow direction and turbulence. |
| Lux meter | Measurement of illumination. |
| Sound level meter | Measurement of operating noise. |
| Microbiological sampling materials | Evaluation of microbial contamination where required. |
All instruments should be suitable for the intended measurement range, and their identification and calibration details should be recorded in the qualification report.
Bio-Safety Cabinet PQ Procedure
1. HEPA Filter Integrity Test
Purpose
The HEPA filter integrity test evaluates whether the installed filter and its sealing arrangements have unacceptable leakage that could compromise the intended filtration performance.
Equipment required
- Suitable aerosol generator.
- Appropriate challenge aerosol, such as the one specified by the approved method.
- Aerosol photometer or another suitable validated measurement system.
Procedure
- Verify the calibration status and suitability of the test instruments.
- Confirm that the cabinet and filter arrangement are appropriate for the selected test method.
- Introduce the specified aerosol challenge upstream of the filter using the approved setup.
- Establish the upstream challenge concentration as required by the instrument procedure.
- Scan the downstream filter face, filter perimeter, seals, and relevant joints according to the approved method.
- Maintain the required probe position and scanning speed specified by the applicable procedure.
- Record the measurements and identify any areas showing leakage above the established limit.
- Investigate any unacceptable result and arrange corrective action.
- Repeat the test after corrective work to confirm that the filter installation meets the approved acceptance criteria.
Acceptance criteria
The acceptance limit must be established according to the cabinet design, filter specification, applicable test standard, and approved protocol.
The source procedure specifies a maximum penetration of 0.01% for a filter rated at 99.99% efficiency or greater. This value should be used only when appropriate to the specific filter, test method, and governing acceptance standard.
A filter failure must not be addressed merely by sealing a leak without determining whether the defect is in the filter media, gasket, housing, or installation.
2. Air Velocity Test
Purpose
The air velocity test measures airflow at defined locations to determine whether the cabinet is operating within its approved airflow specifications.
Equipment required
A calibrated anemometer suitable for the expected airflow and measurement configuration.
Procedure
- Confirm that the cabinet is operating in the specified mode and has stabilized.
- Verify the calibration status of the anemometer.
- Identify the measurement locations from the approved sampling diagram.
- Position the probe correctly for the airflow being measured.
- Record readings at each specified location using the required measurement duration.
- Calculate the required average and evaluate the distribution of readings.
- Compare the results with the cabinet manufacturer’s specifications and approved acceptance criteria.
- Document any abnormal readings and investigate the cause.
Acceptance criteria
The source procedure lists an air velocity target of 90 feet per minute (fpm) ±20%.
This corresponds to a range of 72–108 fpm. However, it is not a universal limit for all Bio-Safety Cabinets. The appropriate velocity and measurement locations depend on the cabinet classification, airflow design, manufacturer specifications, and applicable standard.
A single average reading should not be used to conceal unacceptable local airflow conditions.
3. Airflow Visualization Test
Purpose
Airflow visualization helps assess whether air moves along the intended pathways and whether undesirable turbulence, reverse flow, or disruption occurs in critical areas.
Equipment required
- A suitable smoke or fog visualization device.
- Video recording equipment, where required.
Procedure
- Confirm that the cabinet is installed and operating under the specified test conditions.
- Check that the visualization material is compatible with the equipment and will not introduce unacceptable contamination or residues.
- Introduce the visualization medium at the locations defined in the approved protocol.
- Observe airflow at the working opening, work surface, and other relevant areas.
- Assess the direction of airflow, possible turbulence, and any flow disruption.
- Record observations and retain video evidence when required.
- Evaluate the results against the cabinet design and the applicable acceptance criteria.
Acceptance criteria
Airflow should follow the intended pattern without unacceptable disruption of the cabinet’s protective airflow.
The expected pattern depends on the cabinet design. For example, a vertical laminar-flow pattern should not automatically be imposed on every Bio-Safety Cabinet, because some designs use a combination of inflow and downflow to provide operator, product, and environmental protection.
4. Non-Viable Particle Count Test
Purpose
Particle counting evaluates airborne particle concentrations when this test is applicable to the cabinet’s intended use and approved qualification requirements.
A particle counter measures particles in specified size ranges. It does not determine whether particles are viable microorganisms.
Prerequisites
- Complete the applicable HEPA filter integrity test.
- Confirm that the cabinet is operating under the specified conditions.
- Verify that the particle counter is calibrated and suitable for the required particle sizes.
- Establish the sampling locations and sample volumes in the protocol.
Procedure
- Identify the sampling locations based on the cabinet’s working area and intended use.
- Operate the particle counter according to its approved instructions.
- Position the sampling probe at the defined working height and location.
- Collect samples using the specified sampling duration and volume.
- Record particle concentrations for the required particle-size channels.
- Retain instrument printouts or electronic records.
- Compare the results with the applicable acceptance criteria.
Acceptance criteria
The source document includes the following particle concentration limits for an ISO Class 5 / Grade A classification:
| Particle size | Maximum concentration per cubic metre of air |
| Equal to or greater than 0.5 µm | 3,520 |
| Equal to or greater than 5.0 µm | 29 |
These limits must not automatically be applied to every Bio-Safety Cabinet. A cabinet is not necessarily classified as an ISO Class 5 or Grade A environment, and the appropriate particle-counting requirements depend on its intended use and applicable standards.
The sampling plan should be designed for the cabinet’s working zone rather than applying a cleanroom floor-area sampling table without justification.
If results exceed the approved limit, investigate operating conditions, sampling technique, filter integrity, airflow, cleaning status, and other relevant factors before deciding on corrective action or retesting.
5. Recovery Test
Purpose
A recovery test evaluates how quickly an environment returns to a specified particle concentration after a defined disturbance or challenge, where such testing is appropriate for the equipment and intended application.
Equipment required
A suitable calibrated non-viable particle counter and any other equipment specified by the approved method.
Procedure
- Establish and record the initial operating condition.
- Define the challenge or disturbance and the recovery endpoint in the approved protocol.
- Conduct the challenge using the specified method.
- Monitor particle concentrations at the required intervals.
- Determine the time required to reach the predefined recovery condition.
- Record the observations, particle counts, and calculated recovery time.
- Compare the result with the predefined acceptance criteria, where established.
Acceptance criteria
The recovery time should be assessed against a justified, predefined requirement where recovery testing is applicable.
The source procedure proposes switching off the cabinet for 10 minutes and monitoring particle counts until the original condition returns. This should not be adopted automatically: switching off a Bio-Safety Cabinet can compromise containment and may introduce risks when hazardous biological material is present.
Any shutdown or challenge test must be planned, performed under controlled conditions, and authorized according to the manufacturer’s instructions and laboratory biosafety procedures. A fixed recovery-time limit should not be invented if none has been established.
6. Microbiological Viable Count Test
Purpose
Microbiological monitoring evaluates microbial contamination under defined conditions. It may be used to assess the microbiological condition of the working environment when required by the cabinet’s application and approved monitoring program.
Procedure
- Define the sampling locations and microbiological method in the approved protocol.
- Use suitable microbiological media and sampling materials.
- Expose or collect samples using the specified method and duration.
- Identify each sample with its location, date, and relevant test information.
- Incubate the samples under the approved conditions.
- Record microbial growth and report the results in the appropriate units.
- Compare the results with the applicable acceptance criteria.
- Investigate unexpected or unacceptable results.
Acceptance criteria
The source procedure specifies a total viable count of not more than 1 CFU per plate.
This limit should not be treated as universally applicable to all Bio-Safety Cabinets. The appropriate microbial acceptance criteria depend on the cabinet’s intended use, the sampling method, the exposure duration, the medium, and the site’s approved microbiological monitoring program.
The source method also describes two incubation stages at different temperatures. The appropriate media, incubation temperatures, and durations should be established in the approved method and justified for the microorganisms of concern.
7. Illumination Test
Purpose
The illumination test verifies that lighting inside the working area is suitable for laboratory activities.
Equipment required
A calibrated lux meter.
Procedure
- Ensure that the cabinet is in the specified operating condition.
- Remove materials that could obstruct or alter the light measurements.
- Identify the measurement points specified in the protocol.
- Measure illumination at each location using the correct meter position.
- Record all readings and calculate the average.
- Compare the results with the approved acceptance criteria.
Acceptance criteria
The source procedure specifies:
- Average illumination of at least 750 lux.
- No individual reading below 70% of the average illumination.
These values should be confirmed against the manufacturer’s specifications and the site’s approved requirements before use. They are not universal limits for every cabinet model.
8. Noise Level Test
Purpose
The noise test measures the sound generated by the cabinet during operation and helps verify that the equipment meets its specified operating requirements.
Equipment required
A calibrated sound level meter.
Procedure
- Operate the cabinet under the defined test conditions.
- Control background noise and avoid unnecessary disturbances.
- Position the sound level meter at the location and distance specified by the approved method.
- Record the sound level using the required meter settings.
- Document background conditions and compare the result with the acceptance criterion.
Acceptance criteria
The source procedure specifies a noise level of less than 65 dB.
The applicable limit should be confirmed against the cabinet manufacturer’s specification and the selected measurement method. The measurement location, background noise, operating mode, and instrument settings should be documented so that the result can be interpreted correctly.
Summary of Bio Safety Cabinet Performance Tests
| Test | Main purpose | Acceptance basis |
| HEPA filter integrity | Detect unacceptable leakage through the filter or its installation | Approved filter integrity test standard and manufacturer’s specification |
| Air velocity | Verify the required airflow performance | Cabinet-specific airflow requirements |
| Airflow visualization | Assess intended airflow direction and identify disruptive flow patterns | Cabinet design and approved visualization criteria |
| Non-viable particle count | Evaluate airborne particle concentration where applicable | Applicable classification and approved sampling plan |
| Recovery test | Determine recovery performance where required | Predefined, scientifically justified recovery criteria |
| Microbiological monitoring | Assess viable microbial contamination where applicable | Approved microbiological monitoring criteria |
| Illumination | Verify suitable working-area lighting | Manufacturer’s specification and approved requirements |
| Noise | Verify operating sound level | Manufacturer’s specification and approved requirements |
All results should be reviewed against the approved protocol. Missing data, unexplained discrepancies, or failures should be addressed before the cabinet is declared qualified for its intended use.
Frequently Asked Questions (FAQs) Bio Safety Cabinet Performance Qualification
1. What is Bio-Safety Cabinet PQ?
It is a documented evaluation of whether a Bio-Safety Cabinet meets the performance requirements established for its intended use.
2. Which tests are performed during Bio-Safety Cabinet PQ?
Depending on the cabinet design and intended application, tests may include HEPA filter integrity, air velocity, airflow visualization, particle counting, recovery, microbiological monitoring, illumination, and noise.
3. Which instruments are required for Bio-Safety Cabinet PQ?
Typical instruments include an anemometer, aerosol photometer with a suitable aerosol generator, particle counter, lux meter, and sound level meter. Airflow visualization and microbiological tests require their respective suitable equipment and materials.
4. What is the acceptance limit for the HEPA filter integrity test?
The limit depends on the filter rating, test method, and applicable standard. The source procedure specifies penetration not exceeding 0.01% for filters rated at 99.99% efficiency or greater, but this must be verified against the approved requirements for the specific cabinet.
5. Is an air velocity of 90 fpm mandatory for every Bio-Safety Cabinet?
No. The source procedure specifies 90 fpm ±20%, but acceptable airflow depends on the cabinet classification, design, operating mode, manufacturer specifications, and applicable requirements.
6. Is particle counting required for every Bio-Safety Cabinet?
Not necessarily. Particle counting should be included when required by the intended application, approved qualification strategy, or applicable standard. Cleanroom classification criteria should not automatically be applied to all cabinets.
Read Also
SS Verification by Molybdenum Kit – Complete Procedure
BOD Incubator SOP – Complete Procedure
Microbial Limit Test for Raw and Purified Water
Dehydrated Media Storage, GPT and Disposal – Complete Procedure