Cleanroom Testing and
Certification Basics

Cleanrooms are controlled environments

Designed to limit airborne particulates and other environmental conditions, cleanrooms are certified to a specific class, based on the standard ISO 14644-1, or similar standards. The room must perform, according to the standards, to meet or exceed the ISO parameters to maintain compliance. Cleanroom testing and certification involves checking that the cleanroom is functioning to the specific parameters and ISO classification.

Typically the room is initially certified when construction is completed to ensure it was built to the client’s specifications. The room is also then routinely retested (annually or semiannually) to ensure the quality has not changed during operations. The standards which cleanrooms are tested to are ISO14644-1, ISO 144644-2 and ISO 14644-3.

The certification should include which occupancy state the room was tested: as-built, which is the initial, empty facility, at-rest: which is the room with all production equipment running but no personnel present, or operational, which is the room in full operation. It is also a common practice to test and certify a cleanroom has been renovated or a contamination incident. Selecting which tests to perform are based on many variables, mainly standard requirements, auditing agency or client requirements, or client’s preference. The typical tests are listed below:

(Annually or Semi Annual based upon specification)

Airflow volume / Velocity Readings Assures that both unidirectional (velocity preferred) and non-unidirectional flow (airflow volume preferred) areas are properly balanced and unidirectional zones are maintaining proper air patterns.
HEPA Filter Integrity Testing Test HEPA filters and system for leakage through the filtration system. This test is not required by ISO standards, but many auditing agencies such as the FDA will require it.
Non-Viable Particle Counting Reports the amount of airborne particulate of a specified size in the clean zone. This test determines cleanliness class.
Room Pressurization Testing Verifies that room differential pressures are operating according to the design.

Optional tests are based upon the organization’s need for monitoring, industry requirements and internal QA/SOPs.

Air Balancing Adjusts airflow in the air handling systems to achieve design airflow, room exchange rates and pressure cascade.
Airflow Visualization Testing/ Smoke Testing Verifies the airflow direction using a source of visible fog.
Viable Environmental Monitoring (EM) Air and surface sampling for microbe enumerations.
Room Air Exchange Rates States if the area is meeting its design airflow.
Temperature/Relative Humidity Testing Examines whether the air HVAC controls are functioning uniformly and properly.
Lighting, Vibration, and Sound Testing Assures workers comfort.

Any and all acceptance criteria should be clearly spelled out for the certification company. For instance: the room must meet ISO Class 7 in the operational mode at 0.5 and 5.0 micron. The pressure must cascade from the main cleanroom (highest pressure), to the gown room, to ambient. Or, the airborne sound pressure levels cannot exceed 72 dB “A” scale for worker comfort.

Feel free to contact us or submit a Services Inquiry form for assistance in putting your certification program together and/or reviewing your existing program.