We are setting up a cleanroom for manufacturing. Who certifies the airflow and particle counts?

For a manufacturing cleanroom, the actual testing and certification is normally performed by an independent cleanroom testing/certification company, rather than by ISO itself or the HVAC contractor.

The usual framework is:

• ISO 14644-1 — determines the cleanroom's airborne-particle cleanliness classification (ISO Class 1–9) through particle counting.
• ISO 14644-3 — provides the test methods for things such as airflow, airflow uniformity, recovery, pressure differential, and related performance tests.
• IEST-RP-CC006 — provides detailed practical procedures for cleanroom performance testing; the current revision is CC006.4.IEST+1
• The certifier typically measures airflow velocity/volume, particle counts, room pressure, HEPA filter integrity, and, where applicable, airflow visualization and recovery.Hodess

Who should you hire?

Look for a third-party cleanroom certification/testing firm with appropriately calibrated instruments and qualified technicians. For a regulated manufacturing facility, I'd strongly consider a provider whose testing laboratory is ISO/IEC 17025 accredited for the relevant measurements. For example, some U.S. providers specifically hold ISO/IEC 17025 accreditation for particle counting and airflow measurements.Techmaster Electronics+1

Importantly, ISO itself doesn't send someone out to certify your room. The certification report comes from the testing organization, which documents whether the room meets the specified ISO classification and other acceptance criteria.

If you tell me what you're manufacturing (pharmaceutical, medical device, electronics, food, etc.), the intended ISO class, and where the facility is located, I can tell you exactly what tests you should specify in the certification package and what credentials to require from the certifier.

A certified third-party testing, adjusting, and balancing (TAB) or cleanroom performance testing (CPT) company performs the formal certification of airflow velocity, air change rates, and particle counts.nebb.org+2

Internal quality or facilities teams can monitor parameters day-to-day, but an independent, accredited agency must issue the official compliance certification required for regulatory audits (such as ISO 14644 or cGMP).allometrics.com+2

Certifying Bodies and Professional Standards

When hiring a provider, look for firms certified or accredited by recognized industry authorities to ensure their testing instruments have NIST-traceable calibration:allometrics.com+1

• NEBB (National Environmental Balancing Bureau): Offers specialized NEBB Cleanroom Performance Testing (CPT) credentials for firms and professionals.nebb.org+1
• CETA (Controlled Environment Testing Association): Provides standards and professional accreditations, particularly for controlled environments and compounding/manufacturing facilities.
• NSF International: Frequently accredits testing organizations for life sciences and pharmaceutical compliance.goquantus.com+1

Key Tests Performed During Certification

A standard cleanroom certification and qualification package evaluates multiple integrated parameters:youtube.com+2

If you can share the ISO cleanliness class you are targeting (e.g., ISO Class 7 or 8) and your industry (pharmaceutical, electronics, medical device), I can provide more tailored testing requirements or guidance on local compliance standards.

For a manufacturing cleanroom, the testing/certification is normally performed by an independent cleanroom certification/testing firm, rather than by ISO itself or the FDA.

The usual framework is:

• ISO 14644-1 — establishes the cleanroom's airborne particle classification (ISO Class 1–9) using calibrated particle counters.FDA Access Data
• ISO 14644-3 — specifies the performance test methods, including airflow-related testing and particle classification testing.FDA Access Data
• A qualified cleanroom certification technician/organization comes onsite, performs the tests, and issues the certification/report. Ideally, the testing organization operates under ISO/IEC 17025 accreditation or an equivalent recognized quality system.Techmaster Electronics

A typical certification package includes:

1. Airflow volume/velocity and uniformity
2. Air changes per hour
3. Room pressure differentials
4. HEPA/ULPA filter integrity (PAO/DOP leak testing)
5. Nonviable airborne particle counts
6. Recovery/clean-up testing, where applicable
7. Temperature and relative humidity
8. Airflow visualization/smoke studies where required

The certifier then determines whether the measured particle concentrations meet your specified ISO class.Hodess+1

If you're manufacturing pharmaceuticals, medical devices, sterile products, or compounding, there can be additional regulatory requirements beyond ISO 14644. FDA, for example, recognizes ISO 14644 standards but notes that sterile-drug facilities shouldn't rely on ISO particle classification alone.U.S. Food and Drug Administration

If you tell me what you're manufacturing (pharma, medical device, electronics, aerospace, etc.) and your target ISO class, I can tell you exactly what certification tests you'll likely need and what type of certifier to hire.

Cleanrooms are certified by independent, third-party cleanroom testing and certification professionals or specialized validation service companies.csitesting.com+2

Internal staff typically do not certify their own cleanrooms because regulatory compliance requires unbiased, calibrated equipment and documented proof from accredited professionals.

Who Performs the Certification?

• Third-Party Testing/Validation Companies: Specialized firms that deploy certified technicians to test airflow, pressure differentials, and airborne particle counts.abm.com+1
• Qualified Professionals: Look for technicians holding recognized credentials, such as certification from the Cleanroom Testing and Certification Board International (CTCBI) or the Controlled Environment Testing Association's National Board of Testing (CNBT).csitesting.com+1

The Standards They Follow

Certifying bodies and technicians do not make up their own rules; they test against internationally recognized standards, most notably:

• ISO 14644 (Parts 1 through 7): The global standard for classifying air cleanliness by particle concentration and specifying testing/monitoring methods (such as filter leak testing, airflow velocity, and volume measurements).youtube.com+1
• Federal Standard 209E (FS209E): An older US standard that has been officially superseded by ISO 14644, though legacy facilities may still reference it.csitesting.com+2
• cGMP / EU GMP: Industry-specific guidelines (for pharmaceuticals and medical devices) that map cleanroom grades to strict operational parameters.abm.com+1

Key Tests Included in Certification

When you hire a certification firm, their scope of work for airflow and particle counts typically includes:

1. Airborne Particle Count Test: Using calibrated discrete particle counters to measure the concentration of particles of specified sizes per cubic meter.
2. Airflow Velocity and Uniformity Test: Measuring air speed from filters and across the room to ensure proper air changes per hour (ACPH) and laminar flow dynamics.
3. Filter Integrity (HEPA/ULPA) Leak Testing: Scanning filters to verify there are no leaks in the media or framing.
4. Pressure Differential Measurement: Ensuring proper positive or negative pressure relative to adjacent areas to prevent contamination infiltration.youtube.com+1

If you'd like, I can help you with:

• Finding a local or national testing agency
• Outlining the specific ISO classification levels you might need based on your manufacturing product
• Detailing the difference between as-built, at-rest, and operational testing phases

For a manufacturing cleanroom, airflow and airborne particle counts are normally tested and certified by an independent cleanroom certification/testing firm, rather than by a government inspector.

The usual framework is:

• ISO 14644-1 — establishes the cleanroom's airborne-particle cleanliness classification (ISO Class 1–9).
• ISO 14644-2 — covers the monitoring plan and ongoing verification.
• ISO 14644-3 / IEST-RP-CC006 — provides test methods for airflow, pressure, recovery, visualization, particle counting, etc. IEST's current cleanroom-testing practice is IEST-RP-CC006.4.Institute of Electrical Sciences+1
• The testing company typically performs particle counts, airflow velocity/volume, air changes, room pressure, HEPA filter integrity/leak testing, and sometimes airflow visualization and recovery testing.Hodess+1

Who should you hire?

Look for a third-party Cleanroom Performance Testing (CPT) / certification company, preferably one with NEBB Certified Cleanroom Performance Testing (CPT) personnel or equivalent documented competency. NEBB-certified providers specifically perform cleanroom performance testing to ISO 14644 procedures.Northwest Engineering Service, Inc.

If you're in the U.S., I'd also ask whether their instruments are NIST-traceable/calibrated and, where appropriate, whether their calibration laboratory is ISO/IEC 17025 accredited.Techmaster Electronics

Important: The certifier doesn't decide what cleanliness class you need. Your process/specification determines that (for example, ISO 7 or ISO 8), and the certifier tests whether the completed room actually meets that requirement.

If you tell me what you're manufacturing (medical devices, electronics, pharma, aerospace, etc.) and your target ISO class, I can tell you exactly which tests you should put into the commissioning/certification scope.