By Karen von Holtz, CEO of CSI TestingHow important is it to know what you are getting into? A good portion of new clients that call me say they have just finished building their cleanroom and need it tested. It is rare that they understand what kind of testing is needed beyond particle counting. Often, we find that they do not have a cleanroom that will meet the needs of their product, and fixing a cleanroom can be more costly than building it correctly in the first place.
In order to build the best environment for your product, the product must be analyzed during the process development stage. What kinds of contamination controls are necessary to produce the quality product you have designed? It probably should have a controlled environment, but what controls should your controlled environment have? The Institute of Environmental Sciences and Technology (IEST) has two important documents on design/build/validation of cleanrooms. One is the IEST RP-CC-012 Considerations in Cleanroom Design, and the other is ISO 14644-4 Design, Construction and Start-up of Cleanrooms and associated controlled environments. (See chart on page 36.)
From those documents, and those of the FDA, you will understand that, at minimum, you need: an environment that has a controlled access; a clean air supply through HEPA/ULPA filters, which will provide you with a low contamination environment; an air barrier that consists of the correct amount of positive or negative air pressure; and the correct number of air changes per hour. Beyond that, there may be specific conditions for your product, such as a need for a regulated temperature, relative humidity, special lighting, silicone- or latex-free, and so forth. Furthermore, the documents list items that should be considered and/or specified when designing your clean environment.
Once the environmental controls are decided on, the next step is controlling the operating environment. This includes personnel practices (RP-CC-027), operations (ISO 14644-5 and RP-CC-026), housekeeping (RP-CC-018), garments (RP-CC-003), wiping materials (RP-CC-004), gloves (RP-CC-005), and more. These documents provide a wealth of information to guide the company in the setup of operations, writing the SOPs that control the hiring and training of personnel, the cleaning and maintenance of the cleanroom, and the evaluation of cleanroom supplies.
Prior to full-scale operation, the validation master plan should be finalized. Most often, this should contain three sections: strategy, protocols, and evaluation.
■ Strategy is the design phase that sets the objectives and specifies the results to be achieved. The results are specified as permitted residual limits. These may include class level such as ISO Class 7, amount of room pressure, how many filters, amount of room air changes, lighting, HVAC needs, etc.
■ Protocols cover the implementation stage and will specify how these goals will be achieved.
■ Evaluation describes the means and methods-the tests that will be used to analyze the performance of the cleanroom.
According to the ISO 14644-2 standard, anytime a cleanroom is put into operation or changes its intended use, a “validation” must be performed. First-time validation testing takes place over a specified period of time (usually at least one seasonal cycle) to ensure the cleanroom is functioning as intended and specified. When changes are made to the cleanroom, an assessment of how the changes will affect the cleanroom is performed, and a decision is made of how extensive the revalidation will be. Each time a testing is performed, it is called a “certification,” meaning that the cleanroom is “certified” as meeting the stated standards, SOPs, and/or design criteria.
Each RP or standard uses a variety of terms for each phase of the testing performed.
■ Phase 1 Installation Qualification, As-Built Testing, or Construction Approval. This is testing that proves the environment was correctly installed and that it meets the intended design specifications.
■ Phase 2-Operational Qualification, At-Rest Testing, or Functional Approval. This testing is performed with all the equipment present and operating, but without personnel present. It is necessary to determine that all parts of the installation operate together to achieve the required conditions. Also, if something happens to the environment, this testing phase provides baseline data to prove that the environment is back to a “normal condition” prior to restarting production.
■ Phase 3-Performance Qualification, Operational Testing, or Operational Approval. This is a series of tests/certifications that are carried out to determine that the completed installation achieves the required operational performance with the specified process or activity functioning, and with the specified number of personnel present working in the agreed manner. From this testing data, which is accumulated and trended, the alert and action limits will be set.
Given all this information, how does one determine which tests to perform? Basically, the room, the HVAC system, and all the process equipment must be tested to prove they can continually produce the quality product that was intended and that the process equipment is performing within the intended specification. However, this article only addresses the cleanroom and its related systems.
There are documents that detail tests, methodology, and recommended equipment for cleanroom testing. ISO 14644-3 Test Methods recommend test apparatus, test procedures, and acceptance criteria for determining performance testing. And, IEST has RP-CC-006 Testing Cleanrooms, RP-CC-007 Testing UPLA Filters, RP-CC-034 HEPA and ULPA Filter Leak Tests, and RP-CC-013 Test Equipment Calibration or Validation Procedures. Wading through these documents can be a daunting experience. A qualified independent testing and certification company can help outline an appropriate testing program for each cleanroom or support room.
Unless your product has special needs, a primary testing program might include:
■ HEPA/ULPA filter installation leak test. This test is performed to verify that the filters have been properly installed and are free of leaks.
■ Airflow volume, velocity, and uniformity tests. This test is performed to check the uniformity of the clean air and to verify that there is enough air supply to provide the proper room pressures.
■ Airborne particle count test. This testing verifies that the cleanroom, the personnel, and process equipment is performing to the intended clean level.
■ Room pressurization test. This test is to verify that there is a proper amount of positive/negative room air pressure.
■ Microbial testing of air, surfaces, and measurement of the efficiency of the cleaning process (ISO 14698, Parts 1, 2, and 3).
The newest recommended practice from IEST is RP-CC-019 Qualifications for Organizations Engaged in the Testing and Certification for Cleanrooms and Clean-Air Devices. This document defines recommended qualifications for organizations engaged in testing and certification by establishing levels of competence to be demonstrated by testing personnel. It is intended to provide guidance to equipment owners when they are assessing the credentials of a prospective testing vendor.
Basically, if you don’t know or understand the way to specify the design aspects of your cleanroom, know how to specify disposables and cleanroom service or testing, or even know the right questions to ask service providers, you may not get the information or quality of information that is needed.
One place to go for reliable help and information is the IEST. The IEST is a not-for-profit association whose members are internationally recognized for their contributions to the environmental sciences in the area of contamination control. The IEST is a global leader in the development of recommended practices and standards; and is recognized as an international resource for information on controlled environments through education and the development of recommended practices and standards. Without an organization such as this, it is almost impossible to track the most updated international standards.