Having been at this for decades now, I can honestly say that the happiness and relief that my clients convey post-certification is as consistent as the static environments in which I test. This is due to the fact that most cleanrooms pass the ISO 14644-1 air classification testing. There are those who don’t pass classification testing and those departures from my clients’ facilities are much different, but for now, let’s focus on a glass half full.
In general, clean manufacturers are aware that their process, product, yields, contracts, marketing statements, etc. are all impacted by the actual particle concentration levels of their cleanroom environments. Assuring that those levels are validated when the cleanroom certifier rolls around is a slam dunk for most. The terms pass and fail are part of ISO 14644-1 testing. Obviously, nobody wants to fail. So, when the particle count is finished and concentration levels are 10% of the classification limit, the in-user is happy, but are they in good shape? In other words, does passing the classification test assure quality? Can they rest easy until the next visit?
How do you define certification?
To answer these questions, we must first understand what a cleanroom certification is. More importantly, what is the in-user’s definition of a cleanroom certification? The answer is simply this; whatever cleanroom tests they believe must be conducted in order to maintain compliance. Is it just the particle concentrations of the air? Or is their concern on the surface? Maybe it is filter velocities or filter leaks. It could be room pressurization or electrostatic discharge (ESD). It could be vibration, lighting, noise, viable particulate, out-gassing, etc. Whether it is contractually (as in a manufacturing agreement), legally (as in a marketing statement), or practically (according to internal process parameters), it is the responsibility of the in-user to define self-compliance. It is not the role of the certifier to define this. Our role is to provide data that reflects whether they have met their own compliance parameters.
I have just detailed many areas that may be of importance to the compliance of a specific cleanroom. Please understand that the parameters for compliance can be as numerous as the actual tests to validate compliance. This is due to the fact that contamination control and clean manufacturing is difficult to achieve. Additionally, compliance is a concern that requires constant vigilance and continuing action. Processes, products, etc. may be negatively impacted by a myriad of things that reach far beyond particle concentration levels. So, does passing the classification test assure quality? Answer: Absolutely not. Certainly a low airborne particle concentration level is a “big” positive in the quest to achieve a clean process, but it is not the be-all, end-all of contamination control. A cleanroom is a static environment, but clean manufacturing is dynamic. The introduction of people, process, and tools into the cleanroom environment is a game changer. Once the two combine, we are now talking about produced levels of contamination and the ability of the cleanroom to purge the contamination. Additionally, we are talking about the important role that cleanroom protocol plays in assisting the cleanroom’s ability to “clean itself.” Having a state of the art cleanroom facility is only half the battle. The other half is waged by the primary producers of contamination, and that is the cleanroom personnel.
So, we know that the cleanroom cannot maintain cleanliness levels on its own. We know that cleanroom contamination levels are affected negatively by people, process, and tools. We know that correct cleanroom protocol is a necessity in maintaining optimum contamination control levels. Combine these truths with the fact that most certifications conducted reveal problems and/or concerns found within the cleanroom environment, and then you begin to see that cleanroom certification is not meant to represent the entirety of one’s contamination control program.
Internal monitoring
A common scenario that plays out over and over again is for an in-user to pass the particle concentration test which will provide the desired ISO cleanroom classification. However, it is typical to find problems with HEPA filters (velocities, leaks, etc.), differential room pressures, mechanical issues (non-operational fan units, thrown breakers, etc.), visual issues (damage, incorrect protocol, etc.) and so on. This is a good scenario because the in-user has been alerted to areas that are negatively impacting the clean process. They can discuss the issues, formulate corrective action, and implement a remedy. In the end, the cleanroom’s ability to maintain cleanliness levels has been elevated due to the certification process and the information provided. What is problematic, though, is that the certifier is finding these problems instead of the in-user. How long have the issues been present prior to the certification testing? What was the negative impact of these issues? Could they have been prevented? An internal environmental monitoring plan or EM plan as part of an expansive cleanroom protocol would help prevent this common scenario.
A good friend of mine was once a director for the World Health Organization. He was an epidemiologist, Korean War vet, venture capitalist, and is a brilliant man. Suffice it to say, he has seen a lot of the world. One day he asked me a question: “Do you know what three things will fix all of humanity’s problems?” Being a cleanroom certifier I answered, “No.” He said, “Education, education, and education.” So there it is. To be successful at anything you must want to be successful, believe you can be successful, and ultimately apply an effort toward being successful by educating yourself. Establishing a cleanroom protocol with an environmental monitoring plan requires training and monetary investment. However, doing so can save money, prevent headaches, and keep a process out of crisis mode.
Investment in a handheld particle counter, anemometer, and a manometer is a great start to establishing an EM plan. These devices will assist in quick spot checks of airborne particle concentrations, HEPA filter leaks, HEPA filter velocities, and differential room pressures. Of course, the purchase of test equipment should be in-line with validation concerns. Spot checking should be conducted on a regular basis. Results should be documented and corrective actions should be spelled out for all areas that fail validation. This process of testing, documenting, applying corrective actions, and validation should begin soon after the certification service and continue up to and through each additional visit. Third party validation (certification) is important and so is the ability to validate in-house; but remember, internal spot checking is a benchmarking process and not a third party certification. It is important for all cleanroom personnel, management, and all who play a role in the clean manufacturing process to be educated in contamination control. Understanding its function will help personnel buy into its importance and ultimately improve contamination control abilities.
Do your homework
Don’t wait until your cleanroom certifier rolls around to validate your cleanroom. Ultimately, you don’t want your certifier to tell you anything that you don’t already know about your own facility. Resist the urge to put all of your stock into a single classification test because critical defects can be the result of much more than particulate contamination. Finally, understand that contamination control is an ongoing process that must adapt as changes occur. The only way to stay ahead of issues it to have the ability to test and validate internally.
Stefan Hocom is the Owner and Vice President of CPS Certification Services Inc., located in Northern California. He has over 20 years’ experience in the clean manufacturing industry providing testing and consulting services. www.cpscertification.com
This article appeared in the October 2014 issue of Controlled Environments.
