Cleanroom Validation – Basic Principles


Cleanrooms are expensive to build and maintain because they must be customized to produce a specific product that is subject to special requirements that have been established to minimize contamination.

When building or extending a cleanroom, it is crucial to design it right from the outset to ensure that all requirements are met initially. Changes after the fact can be very costly.

Cleanroom Design Considerations

Highly regulated environments like those found in the manufacture of medical devices as well as the pharmaceutical industry, and the manufacture of PCBs, require assurance that critical processes can be performed within controlled conditions that have been validated.

In order to validate a cleanroom environment it is necessary to demonstrate that:

  1. air supplied to the cleanroom is of sufficient quantity to dilute or remove contamination generated within the cleanroom,
  2. air supplied to the cleanroom is of a quality that will not add to the contamination levels in the cleanroom,
  3. air moves in the direction from clean to less clean areas,
  4. air movement within the cleanroom shows that there are no areas with the room with high concentrations of contamination, and
  5. manufacturing processes can be done in an environment that meets its microbial contamination levels.

Cleanroom Validation Life Cycle

The process of designing, building, and validation testing and certification of a cleanroom consists of five phases.  They are:

  1. Design qualification,
  2. Installation qualification,
  3. Operation qualification,
  4. Performance qualification, and
  5. Cleanroom certification.

Each phase is consistent with implementing, designing, and testing to specific requirements.  Methods for evaluation and measurements for Certification are specified in ISO 14644-3. It calls for the following ten tests:

  1. Airborne particle count test
  2. Airflow test
  3. Air pressure differential test
  4. Filter leakage test
  5. Flow visualization test
  6. Airflow direction test
  7. Temperature test
  8. Humidity test
  9. Recovery test
  10. Containment leak test

Cleanrooms are validated to a required class of cleanliness that is driven by user requirements as defined in ISO 1464-1.  Once certified to a particular class, the cleanroom factors need to be monitored to ensure that parameters have not changed or drifted, and that the environment is under control. A constant monitoring program is mandated after certification. Compliance requirements are specified in ISO 14644-2 

Cleanroom validation is more than simply counting particles.  It includes numerous different tests that must be performed in various cleanroom states in order to verify that the cleanroom is fit for its intended use and meets the stipulations set forth for the classification requirements governing the cleanroom application.

The information supplied in this article is for guidance only. Not all cleanrooms will use the same procedures. Follow your specific cleanroom or company procedural manual before this guide.