New challenges in contamination control

The leadership role of IEST in shaping future research and practices

By Tengfang Xu, PhD, PE, Technical Vice President, IEST; Jan Eudy, Past President, IEST; Chuck Berndt, Communications Vice President, IEST

A leading industrial standards-writing organization since 1953, IEST has established seven tracks of Recommended Practices (RP) in the Standards and Practices (S&P) portion of the Contamination Control (CC) program, including the most recent program in Nanoscience and Nanotechnology. In addition, there are other parallel activities in IEST’s Design, Test, and Evaluation and Product Reliability divisions. Within each of these programs, scientists, engineers and contamination control professionals from all over the world interact closely in working group meetings, seminars and tutorials. Together they have developed, published and disseminated technical information and industrial standards, including RPs, reference documents (RDs), and ISO standards to address ever-evolving challenges in contamination control and sustainable development of the industries served by IEST.

The series of standards, RPs, and RDs are developed through years of discussion, deliberation and review, thus providing peer-reviewed best practices, standardized procedures and test methods to furnish guidance and address problems in contamination control. In general, IEST’s procedures for the development of standards, RPs, or RDs are in accordance with its status as an ANSI-accredited Standards Developer Organization (SDO). Specifically, RPs and RDs are formulated by IEST Working Groups (WGs) through a cooperative exchange of knowledge, experience and ideas that culminates in useful and timely information invaluable to all that avail themselves of this knowledge. These documents are reviewed every three years so that new knowledge, information and methods may be integrated into them in a timely manner.

All WG member contributions are provided by professionals on a volunteer basis. There are increasing challenges associated with keeping up with new knowledge requirements. However, IEST has successfully relied on ever-evolving leadership and concerted efforts by numerous volunteers to develop, revise and publish new documents at a faster pace than had been seen in recent decades. For example, eight updated revisions of existing or brand new RPs have been published since 2005, and approximately seven more RPs and RDs are well positioned in the pipeline for official publication by early 2007.

Due to their quality and timeliness, many IEST RPs are primary references and sources of information for compliance with the ISO 14644 series of international standards developed by ISO Technical Committee (ISO/TC) 209, Cleanrooms and associated controlled environments. Additionally, IEST conducts technical seminars, workshops and tutorials at its annual technical meeting (ESTECH), its Fall Conference, and online to assist related industries to better understand the “state-of-the-art” philosophies and effectively utilize IEST Recommended Practices and ISO standards.

Being the leading organization and a voting member of the ANSI-accredited U.S. Technical Advisory Group (TAG) to ISO/TC 229, Nanotechnologies, IEST is in a unique position to contribute its expertise in developing international standards for controlled environments to anticipate the unique needs of the emerging nanoscience/nanotechnology industry. For example, the IEST has formulated a new program to address the complex issues relevant to all industries working in this area. It includes nanoparticles, other relevant contamination control issues, and building facilities to conduct research and produce products related to nanotechnology. Leading industry experts in this area have been gathering at IEST conferences since the Fall Conference in 2005 and are working diligently on a first-ever industry road map and subsequent RPs in the IEST Recommended Practices NANO200 series. The first document, titled “Planning, Design, Construction & Operations Considerations for Facilities Engaged in Research or Production at the Nanometer Scale,” is, as mentioned earlier, the “road map document” for all industries building facilities to perform research and manufacturing at nanoscale levels. The document is scheduled for publication in the latter part of 2007.

IEST leaders are continually embracing new challenges and taking advantage of new opportunities to lead the way in the development of groundbreaking documents. We invite you to join in and participate in the relevant WGs, whether you are from the industrial sector or from academia. To increase your knowledge of the constantly evolving issues of the contamination control industry, you will want to obtain the most recent versions of these documents and become an active part of the organization. For further information, please visit

The following is an overview of the IEST Working Groups and Recommended Practices.

WG-CC001: HEPA and ULPA Filters

This RP covers basic provisions for HEPA (high-efficiency particulate air) and ULPA (ultra-low penetration air) filter units as a basis for agreement between buyers and sellers. Filters that meet the requirements of this RP are suitable for use in clean air devices and cleanrooms that come within the scope of ISO 14644-1 and -2 (formerly Federal Standard 209) and for use in supply air and contaminated exhaust systems for which extremely high filter efficiency (99.97 percent or higher) for submicrometer particles is required. Six levels of performance and six grades of construction are included in this discussion. IEST-RP-CC001.4 was published in November 2005 and is due for review in November 2008.

WG-CC002: Unidirectional Flow Clean-Air Devices

This RP covers definitions, procedures for evaluating performance, and major requirements of unidirectional-flow clean-air devices. It may be used to define a basis of agreement between customer and supplier in the specification, procurement, and certification testing of unidirectional flow clean-air devices with self-contained motor-blowers and nonpowered terminal units with replaceable filter. It also presents recommendations for recertification under direction of the customer on devices owned by the customer. IEST-RP-CC002.2 was reviewed and validated in June 2004 and is due for review in June 2007.

WG-CC003: Garment System Considerations for Cleanrooms and Other Controlled Environments

This RP addresses the gowning of personnel as an important aspect of cleanroom contamination control. It provides non-mandatory guidance for the selection, specification, maintenance, and testing of apparel and accessories appropriate for use in non-aseptic and aseptic cleanrooms and other controlled environments. IEST-RP-CC003.3 was published in August 2003 and the Working Group is currently planning version 3.4.

WG-CC004: Evaluating Wiping Materials Used in Cleanrooms and Other Controlled Environments

This RP describes methods for evaluating, selecting and testing wipers used in cleanrooms and other controlled environments for characteristics related to both cleanliness and function based on intended usage. IEST-RP-CC004.3 was published in August 2004 and is due for review in August 2007.

WG-CC005: Gloves and Finger Cots Used in Cleanrooms and Other Controlled Environments

This RP describes procedures for testing, selecting and evaluating gloves and finger cots used in cleanrooms and other controlled environments. Tests are provided for determining cleanliness, physical and chemical integrity, and other relevant properties. Guidelines are also provided to assist users in the proper selection of gloves or finger cots. IEST-RP-CC005.3 was reviewed and validated in September 2006 and is due for review in September 2009.

WG-CC006: Testing Cleanrooms

This RP covers testing methods for characterizing the performance of cleanrooms. It is intended to assist planners, designers, manufacturers and buyers in preparing detailed specifications for cleanroom procurement and for assuring cleanroom operational compliance. Performance tests are recommended for three types of cleanrooms at three operational phases. Where the test method is affected by the type of cleanroom, alternative procedures are defined. For some of the tests, several different methods and instruments are allowed so that different end-use considerations can be accommodated. The test methods also may be used or adapted for periodic monitoring of cleanroom or clean zone performance capability. IEST-RP-CC006.3 was published in August 2004 and is due for review in August 2007.

WG-CC007: Testing ULPA Filters

This RP covers production testing of filters for particle penetration and pressure drop of ultra-low penetration air filters (ULPA). The penetration range of the procedure is 0.001 percent to 0.0001 percent, using particle counters. This procedure describes the equipment, aerosol properties, processes, and calculations for determining the efficiency of ultra-low penetration air filters, using particle counters. The procedure may be applied to production applications. Guidelines are provided for constructing a suitable test duct and sampling system. Also provided are test criteria for quantifying penetration in the range of 0.001 percent to 0.0001 percent, using test aerosol particles in the size range of 0.1


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