An art exhibit in London1 inspired us to ponder changing views about the definitions and implications of soil, residue, contamination, and especially the design and operation of controlled environments. We were amused by the satirical cartoons, and we were especially struck by depictions of the ultimate fashion in cholera protection, one of which is reproduced below (Figure 1).* Biohazard suits have evolved, as have manufacturers’ views of what is necessary and appropriate in cleanroom design and operation.
Cleanrooms are expensive real estate in terms of initial capital investment, upkeep, and employee education. In times of exacting product performance requirements, of economic challenges, and of increased competition, making wise decisions about controlled environments is a must.
The issue is analogous to critical cleaning of product in that more cleaning is not necessarily better. Overly-engineered cleanroom design, unneeded activities in the cleanroom, and inappropriately-complicated cleanroom discipline programs can be both costly and may in fact be counterproductive. Perhaps using this fashion illustration as inspiration, we invite you to consider what aspects of cleanroom design are crucial, what might be optional, and what, in your application, might be counterproductive. As further inspiration, we invited some colleagues, all with extensive experience in cleanrooms, to provide comments and ideas.
WHAT KIND OF CLEANROOM?
Why even build a cleanroom if all you want to accomplish is to control visible particles (in the range of 25 to 50 microns and larger),” asks Scott Mackler, Founder and Principal at Cleanroom Consulting LLC in Pittsford, New York. “Cleanrooms require a large capital investment; and there is also periodic certification as well as employee training.” Mackler suggests a more cost-effect approach. “A controlled environment along with appropriate housekeeping practices may be all that is needed.”
Kelly Barton, Senior Sales Engineer at Clean Rooms West, Inc. in Tustin, California, adds that too often people who set up cleanrooms “assume that what other companies do is the best approach. Because they have not fully explored the basics of cleanroom operation, they may write specifications that are unreasonable and are not pertinent to their application. This boxes them in.”
Mackler adds that “companies over-specify and then under-control. They don’t watch the operation. People say they need a Class 10,000 cleanroom, but they don’t know why. They say customers expect it.”
Keith Weber, Vice President of Engineering at Clean Rooms International Inc. in Grand Rapids, Michigan, comments that “we deal with many first time users who either understand the value of a cleanroom and decide that having one would enhance their standing in their marketplace, or their customer is demanding they produce their goods in a cleanroom. Chances are they do not have an expert on staff to determine what constitutes a cleanroom and then what class of room is needed. So they may delegate this to an intern or other staff member to investigate and come up with an action plan and costing.”
We agree that a higher class of cleanroom is not necessarily better. A costly cleanroom will not in and of itself guarantee that the product will be free of contamination and defects. In fact, that is why our column is titled “Contamination Control In and Out of the Cleanroom.” We see the issue of over-specification not only in cleanrooms, but also in cleaning chemicals, cleaning equipment, and other manufacturing chemicals and equipment.
PUSHING THE ENVELOPE/CUTTING CORNERS
Weber notes that “to the uninformed, a cleanroom is a cleanroom is a cleanroom. Because of the initial cost they might opt for a Class 100K room, get it ordered, installed, and operational only to find out that they need a Class 1K. Then again, if a Class 1K room is installed and a Class 10K or 100K room is all that is required, there is a serious capital investment wasted along with additional operation costs. Usually a room can be downgraded without too much additional expense. However trying to create a cleaner environment with a room that was not designed for it is not nearly as easy. Seldom can it be accomplished merely by adding a few more filters.” Weber adds that “it would be more productive if early on in the process the manufacturer had enlisted the help of those with experience and expertise in cleanrooms who know the right questions to ask.”
“Manufacturers should ask why they need ESD floors,” asserts Mackler. “Unless you have very large parts that cannot be grounded as they are moved, money might be better spent on continuous monitoring of work stations and operator grounds, on using appropriate materials of construction for the stations, and on good humidity control. The floors then become a secondary control, like an ‘extended warranty.’ Not everyone needs that extended warranty.”
Weber provides another example of where cutting corners during construction may backfire. He explains that smaller pharmaceutical compounders responding to USP <797>2 have been known to install the proper filtration system but they defer installing air conditioning. “The drawback of this supposed cost-cutting measure becomes obvious when August rolls around. The workers are uncomfortable; the potential for mistakes is higher; and perspiration can contribute to contamination.” Weber adds that adding air conditioning after the fact is typically more costly than if it had been part of the original construction. “Unfortunately,” adds Weber, “while compliant filtration systems may have been installed, the retrofitted air conditioning may permit entry of unfiltered air.”
AIR SHOWERS
Air showers are a controversial capital investment. Some experts question their efficacy. We suggest you use the following comments as food for thought.
Mackler notes that people spend $30,000 apiece on air showers. The effectiveness is questionable; the cost is high. “They are no better than a ‘touchless’ car wash.” Mackler adds that because they have spent money on air showers, “people become lax about cleaning protocols; they think the shower will protect them; and that’s nonsense. Even if an air shower were effective, it does not mean that you can neglect gowning.” Mackler suggests that time and money would be better invested in developing protocols for gown sizing, for gowning, and for bagging and debagging and cleaning and verification.
Ralph Kraft, President of RKI Cleanroom Services in Rochester, New York, asks, “why try to impinge particles on the fabric by blowing high velocity air on the cleanroom garment, when the fabric itself should really be vacuumed.” Kraft explains that whether or not air showers work or are cost effective has been a topic of controversy for years and asks those considering an air shower to “justify the cost of an air shower and show data to indicate the need for an air shower.” However, as Kraft explains in his training seminars, “The air shower provides a physical barrier to psychologically remind everyone that they are going from a less clean area to a cleaner area.”
“I think air showers may have their place in Class 10 operations and maybe in Class 100 environments,” explains Barton, adding that, “in my opinion, in higher classification rooms, it would be difficult to statistically justify them. Their only value at that point is to provide a definitive portal into the controlled environment with the hope of establishing a “mind set” for operators—an expensive training tool.”
Additional published data regarding the efficacy of air showers in various contemporary cleanrooms would help clarify the issue. In our opinion, such data would be particularly useful where there is third party oversight. Peer review might also be helpful. Having said all of this, you, the manufacturer, need to decide if air showers should be used, based on the process, your own manufacturing experience/background, and the advice of your designated experts.
PROCESS FLOW AND THE THOUGHT PROCESS
We often explain that critical cleaning is not the cleaning agent alone, not the cleaning equipment alone, but rather the process. Similarly, setting up a cost-effective cleanroom that supports production of high-quality product has to be considered in the context of the manufacturing process. Kraft explains that “the main thing we’re trying to accomplish is, to get the cleanroom user to think and to evaluate their specific requirements.”
Weber adds that “when bids go out, many suppliers are competing for your dollars. You can’t just pick an item out of a catalogue. Just because you sign a very large check does not necessarily mean you are getting the best cleanroom or even what you really need. There is value to getting someone to help early on in the procurement process.”
In our next column, we continue our discussion of non-superfluous cleanrooms.
References
- “Dirt,” an exhibit at the Wellcome Collection, London, UK (2011); we thank Anselm Kuhn, from Finishing Publications, for suggesting this exhibit to us.
- “USP <797> Guidebook to Pharmaceutical Compounding—Sterile Preparations,” 2008; available from The United States Pharmacopeial Convention.
* We would like to remind our readers that, while progress has been made in controlled environments and in public health, cholera is still prevalent and deadly in portions of the globe with poor nutrition and sanitary conditions.
Barbara Kanegsberg and Ed Kanegsberg, Ph.D. “The Cleaning Lady” and “The Rocket Scientist,” are independent consultants in surface quality including critical/precision cleaning, contamination control, and validation. They are editors of “The Handbook for Critical Cleaning,” CRC Press; an updated two-volume second edition. Contact BFK Solutions LLC, 310-459-3614; [email protected].
