Reference for Cleanroom Performance Testing and Relevant Certification Standards
2026-06-10
Cleanroom testing is an essential procedure after construction and before handover to the owner. Whether the test results meet the standards directly determines if the cleanroom satisfies production requirements.
In accordance with IES-RP-CC006.2, cleanrooms are classified into three operational states: as-built, at-rest and operational. The testing methods are determined by the cleanroom design type and its operational state.
Operational States of Cleanrooms
Generally, only the basic as-built test is specified in cleanroom construction contracts, while at-rest and operational tests are often omitted due to tight construction schedules. We still recommend that both contractors and owners conduct tests under at-rest and operational conditions to ensure the cleanroom complies with design requirements. Comparing test results obtained under these two states helps effectively identify existing problems.
For instance, cleanliness may meet standards under the at-rest state but exceed limits under the operational state. Possible causes include poor cleanroom management: inadequate cleaning during equipment installation, improper cleaning procedures, lax on-site management, and incorrect equipment placement that blocks return air vents or air supply from filters.
Therefore, we suggest performing tests under both as-built and operational conditions.
Cleanroom Testing Standards and Conventions
Virtually all cleanroom tests are conducted in accordance with internationally recognized standards, including ISO 14644-1, IEST-RP-CC006.2, NEBB Manual and the discontinued FS-209E. These standards and practices provide fundamental guidelines for cleanroom testing and certification. In practice, however, owners and contractors may reach separate agreements on technical indicators, testing methods and acceptance criteria based on specific product and process requirements.
Accordingly, most acceptance criteria are determined through negotiations between owners and contractors, with reference to recommendations from professional cleanroom testing and certification bodies. Independent third-party testing firms are generally capable of proposing tailored testing solutions. We therefore recommend involving such organizations at the early stage of discussions on technical parameters, testing methods and acceptance standards. In case of discrepancies over parameters or criteria, these professional bodies can mediate between owners and contractors with their expertise.
Selection of Test Items
The recommended cleanroom test items include filter air velocity and its uniformity, filter installation leak testing, pressure differentials, airflow parallelism, cleanliness level, noise, illuminance, temperature and humidity. These basic items cover both primary and secondary tests and shall conform to the original design standards and parameters of the cleanroom. All testing and certification shall be completed prior to handover to the owner.
Four core items are the most essential: filter air velocity and uniformity, filter installation leak testing, pressure differentials and cleanliness level. These must be finished before equipment is moved into the cleanroom. Other secondary tests such as airflow parallelism (only for unidirectional flow cleanrooms), temperature, humidity, illuminance and noise also need to be conducted, as they are closely related to air movement and environmental parameters. We suggest carrying out all the above secondary tests at least under the operational state.
Cleanroom performance testing is the means to verify whether a cleanroom project meets relevant standards, and it directly determines if the facility satisfies production requirements. Therefore, enterprises shall attach great importance to cleanroom performance testing.
