Evolving ISO standards serve the global cleanroom market


Latest publication completes series of cleanroom standards

By David Brande, Chair, ISO/TC 209

The publication in July 2007 of a new International Organization for Standardization (ISO) Standard, ISO 14644-6 Cleanrooms and associated controlled environments-Part 6: Vocabulary, represented a milestone for ISO Technical Committee (TC) 209. With the new standard, TC 209 fulfilled its original goal to create a series of 10 standards to meet the needs of the global cleanroom industry in a new millennium.

Despite this significant accomplishment, the work of ISO/TC 209 is ongoing. Working Group (WG) 1 already is well along in preparing the second editions of ISO 14644 Part 1: Classification of air cleanliness and Part 2: Specification for testing and monitoring to prove continued compliance with 14644-1. Published in 1999 and 2000, respectively, these two standards are the cornerstones of the series. In addition, two new WGs were added to the original roster in order to meet current needs in classification of contamination. Part 8: Classification of airborne molecular contamination was published in 2006, and WG 9 is developing Part 9: Classification of surface particle cleanliness, currently out for international ballot to move forward as a Draft International Standard (DIS). In addition, WG 8 will be proposing the development of a new standard on surface chemical contamination when ISO/TC 209 meets in Chicago on November 9 and 10, 2007, in conjunction with the IEST Fall Conference. Table 1 lists all current documents in the series.

The first 15 years

In 1992, with European unification on the horizon, the Institute of Environmental Sciences and Technology (IEST) asked the American National Standards Institute (ANSI) to petition ISO to organize the development of international cleanroom standards. The objective was to build consensus on air cleanliness classification, design criteria, test methods, and operational procedures, thereby eliminating trade barriers created by hundreds of existing global national standards.

In response, ISO formed ISO/TC 209, “Cleanrooms and associated controlled environments,” in 1993. IEST was named secretariat for the committee, which currently includes more than 50 representatives from 20 countries. Richard (Dick) Matthews was appointed chair. The TC then set goals and objectives and assigned tasks to WGs composed of expert volunteers from countries wishing to participate in the development of the standard. U.S. representatives from the microelectronics and biopharmaceutical industries have participated in an effort to provide the perspectives of two industries that have very different requirements for controlled environments.

Initially, the immediate need was for two standards encompassing 10 separate documents: Parts 1-7 of the 14644 series and a three-part ISO 14698 biocontamination series. (The third part in the 14698 series was eventually dropped from the work program and Part 8 was added, once again bringing the total to 10 standards.) Soon after beginning this monumental task, the committee discovered that the diverse languages and cultures of the participating nations left many varied and uniquely different uses of words and intent. As a result, it was decided the Vocabulary document would not be published until after the committee’s 10 documents were completed in order to incorporate terminology from all of the other standards. The newly published ISO 14644-6 is an important compilation because it harmonizes the definitions of cleanroom terms used in international contracts.

In the mid-1990s the biopharmaceutical industry began to show promise in using barrier isolators for critical work. Originally begun as a WG on minienvironments and isolators, WG 7 was established in 1994 under the leadership of the United States to support this fast-growing new technology. The concept and language of the document was expanded and published as the standard Part 7: Separative devices (clean air hoods, gloveboxes, isolators and minienvironments) in 2004.

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Technological breakthroughs continued in the industries served by cleanrooms and the committee agreed to expand the original 14644 series of 10 documents in order to assist the industry in further defining classification of contamination. The committee formed an additional WG in 1998 to address the potential for molecular contamination in controlled environments. As WG 8 began to sort through the incoming information, it became evident that the best approach would be to develop separate documents on surface and airborne sources of molecular contamination. WG 8 concentrated on airborne molecular contamination, publishing Part 8: Classification of airborne molecular contamination in 2006, and WG 9 was created to begin development of Part 9: Classification of surface particle cleanliness, currently out for international ballot to move forward as a DIS. A key stage in document development is the DIS stage, as these documents may be used as trade references per agreement between a buyer and seller. During the next ISO/TC 209 meeting in November, the committee will also review a proposal by WG 8 for a new standard on surface chemical contamination.

Looking ahead

As the first chair of ISO/TC 209, Matthews was instrumental in setting goals and objectives for the committee and oversaw the remarkable progress of the nine WGs during his 12-year tenure. When the mantle of responsibility was passed to me in January 2006, the original goal of completing a series of standards for the international cleanroom industry was near completion. Now, with ISO 14644 and ISO 14698 including 11 parts between them, the committee continues to meet yearly to review existing documents and evaluate requirements for new standards.

ISO requires a formal review of all standards every five years. If reviewers determine that the document is still current, the standard will be confirmed for another five years. Otherwise, the standard may be withdrawn or, as was the case with ISO 14644-1 and 14644-2, recommended for revision. Although published a year apart, Parts 1 and 2 are being revised in tandem because they are complementary. WG 1, “Airborne particulate classes,” which is responsible for both parts, was reactivated and the task of refining these core documents began under the leadership of WG convenor Gordon Farquarson of the United Kingdom. The WG has reviewed airborne particulate classification factors, sampling requirements, and other clauses, and is closing out its two-year task with some noteworthy improvements that will make the documents clearer and more uniform throughout all industries.

When ISO/TC 209 met in 2006 at the International Confederation of Contamination Control Societies (ICCCS) conference in Beijing, China, the United Kingdom requested that WG 2 be reactivated to take on the task of improving the biocontamination series, ISO 14698 Parts 1 and 2, which are scheduled for review in 2008. The committee voted to form an ad hoc subcommittee to report back to ISO/TC 209 during the next technical committee meeting in fall 2007. William Whyte of the United Kingdom chaired this ad hoc group, which met in France in March 2007. To continue the ever-evolving work of ISO/TC 209, the technical committee-as well as WGs 8 and 9-has scheduled meetings in November in conjunction with the IEST Fall Conference in Chicago.

The next few years promise to be an exciting, productive period for members of the global cleanroom community participating in ISO/TC 209, as each of the standards is reviewed in turn and the original mission of the committee is upheld.

David Brande has 22 years of experience in the cleanroom certification industry, including 19 years as principal of Contamination Control Technologies, Inc. Before his appointment as chair of ISO/TC 209 in January 2006, Brande served 11 years as expert council for ISO 14644 Part 3. He is a past president and former board member of Controlled Environment Testing Association (CETA). A senior member of IEST, he has been involved for more than 15 years in the development of IEST Recommended Practices.

About IEST

Founded in 1953, IEST, the secretariat for ISO/TC 209, Cleanrooms and associated controlled environments, is an international technical society of engineers, scientists, and educators that serves its members and the industries they represent (simulating, testing, controlling, and teaching the environments of earth and space) through education and the development of recommended practices and standards. IEST is an ANSI-accredited standards development organization. For more information on the ISO/TC 209 Standards or to order the ISO standards featured in this article, contact IEST at or visit the IEST web site at