Debunking the Myth: Enhanced Clean Devices

by Richard A. Matthews

Myth: There is nothing new in cleanrooms. Reality: So what is an ECD?
Some would argue as we come to the end of 1999 that there has been nothing new in cleanrooms lately.

Sure, there's been a slowdown in certain microelectronics areas, a consolidation in pharmaceuticals and significant growth in medical device, automotive, and other peripheral cleanroom market areas.

There has been consolidation among cleanroom industry suppliers, but for every merger there are dozens of start-ups. Those are the dynamics of business.

A similar dynamic is at work in the struggle for more cost-effective clean space. This is where the ECD comes to the forefront. ECD is a generic term for a myriad of specialty clean space environments. ECD stands for enhanced clean device.

Its current definition as developed by Working Group #7 of ISO/TC209 is as follows:

Enhanced Clean Device (ECD)—Equipment utilizing physical and/or dynamic barriers to create improved levels of separation between the inside and outside of a defined volume.

How do we translate this definition into something meaningful, something easy to picture, something practical?

Interestingly, this has already been done in the practical world. It has been done by those with a specific need in a specific industry area. For example, we use the term “minienvironments” in the electronics industry. People in healthcare industries refer to them as “isolators” or “barrier technology.” For the nuclear industry, they are called “gloveboxes.” Other devices such as transfer stations, transfer carts, biohazard containment hoods, all apply to a specific device which is really a form of ECD.

ECDs utilize physical or dynamic barriers to create separation. These barriers can be curtains of air or solid steel walls. They typically integrate personnel interface. They can be 100 percent self-contained. They can have built-in glove sleeve systems and associated transfer devices. They are clean environments but they are not cleanrooms.

The term ECD arrived out of a necessity to coin a term that generically represented all of the above without favoritism to a particular industry or end-use application. This newly coined term also had to be unique so it wouldn't conflict with closely related terms or acronyms.

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In the early meetings of Working Group #7 of ISO/TC209, it was interesting to observe the dynamics of people from different clean backgrounds adamantly convinced that only they had the correct technology, that their particular industry was superior, that things could only be done properly their way. Compounding these attitudes was the mix of languages and their inherent limitations and/or translation options.

Under the tutelage of chairman Dr. David S. Ensor of the USA, the dynamics of this Working Group changed as people opened their minds to learn why others did what they did in their particular clean environment. It became apparent that a glovebox (nuclear) is an isolator (healthcare) is a minienvironment (microelectronics), but these terms by themselves were too limiting in scope; i.e., too specific, not generic.

It was necessary to create a term that encompassed all of these individual specialty clean environments and simultaneously allowed for future options. It also had to be differentiated from being a cleanroom, yet be applicable to the need for clean environments. The term could not be offensive and yet it had to be realistically translatable into other languages. After much discussion, correspondence, and heated debate, the term Enhanced Clean Device was coined.

The soon-to-be-published ISO Standard on ECDs, ISO 14644-7, has a clearly defined table and scale for describing the differences in sophistication and degree of containment between the various ECD design options. It comprises 51 pages of solid technical guidance for anyone needing an ECD in a manufacturing process. Copies may be obtained from the Institute of Environmental Sciences and Technology (

As of this writing, ECD is the term of choice to satisfy the definitions given above. Interestingly, not all involved on ISO/TC209 and the member nations' cleanroom technical groups are happy with this term. So far, no proposed alternative term has been able to generate more appeal than ECD.

Do you have a better idea? If so, please contact either Dave Ensor ([email protected]) or myself ([email protected]). Time is of the essence. We will be freezing ECD (or your better substitute) in early 2000, for that is when ISO will be promulgating the new universal global standards for these types of clean environments.

Anyone seeking to reduce the cost and/or amount of clean space required to perform a specific task should definitely consider ECDs. They may well fit your enhanced needs.

P.S.The most significant change in cleanrooms in 1999 was the publication of ISO 14644-1, which defines the new global classes of air cleanliness. ECDs are part of this change.

Richard A. Matthews is founder of Filtration Technology Inc. (Greensboro, NC) and president of Micron Video International. He is chairman of the International Organization for Standardization Technical Committee ISO/TC 209 “Cleanrooms and associated clean environments,” and past president of the Institute of Environmental Sciences and Technology. He is on the CleanRooms Editorial Advisory Board.


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