Revised, new, and future recommended practices


Highlights from IEST’s contamination control division Standards and Practices Committee 3: Procedural

By Jim Ohlsen, PhD, Entegris, Inc., and director of IEST’s SPC 3: Procedural

The Institute of Environmental Sciences and Technology (IEST) is responsible for the origination, publishing, and revision of more than 35 recommended practices (RPs) on topics of interest and of value to the contamination control industry. Currently, IEST has 42 working groups (WGs) engaged in RP production. The contamination control (CC) division of IEST is involved with the detection, measurement, and control of all forms of contamination in cleanrooms and other controlled environments. The CC division is divided into seven related Standards and Practices Committees (SPCs) covering the general categories of filtration, operational products, procedural issues, facilities, environmental control, reference documents, and nanotechnologies. Each SPC is further organized into WGs that are responsible for publishing RPs-a vital tool when establishing a comprehensive contamination control program.

This article will focus on SPC 3: Procedural and specifically, the activities of six WGs: two that issued new and revised RPs in early 2006, two that have just been published, and two new WGs that are working toward publication of new RPs within the next three years.

New and revised recommended practices

IEST-RP-CC013.2, Calibration Procedures and Guidelines for Select Equipment Used in Testing Cleanrooms and Other Controlled Environments, is new and scheduled for publication later this year. This RP covers procedures for validating and calibrating instruments used in characterizing cleanrooms and for determining intervals of calibration. Included are general procedures for calibrating photometers, aerosol generators, and anemometers. References for calibrating other instruments are provided, where available. The document provides test-equipment users and quality personnel with precise information on the calibration of aerosol photometers, aerosol generators, and anemometers, plus how often to perform the calibrations. It also reinforces to quality personnel good testing practices, from certification through the proper care and use of these instruments.

“This document was written to provide in depth details regarding the process of calibrating both linear and logarithmic aerosol photometers,” comments David Crosby, chair of WG-CC013. “The RP thoroughly covers the calibration of Laskin nozzle aerosol generators and anemometers.” Table 1 of the document, “Recommended Initial Calibration Intervals,” is up-to-date and reflects current practices. Appendix A lists related standards and published procedures (e.g., calibration reference documents or procedures) for many instruments, including pressure gauges, thermometers, and sound level meters, used in testing cleanrooms and other controlled environments. Appendix B addresses proper instrument care, handling and transportation, while Appendices C and D present examples of photometer test procedures and principles of wind tunnel operation, respectively.

IEST-RP-CC014.1, Calibration and Characterization of Optical Airborne Particle Counters, is new and is also scheduled for publication soon. This RP covers procedures for calibrating and characterizing the performance of optical particle counters that detect and size single particles in air and other gases. Included are methods for determining the sizing and counting accuracy of these instruments.

The chair, David Chandler, says of the RP: “The committee that developed this RP was formed of IEST members who have experience in the calibration and application of particle counters. Some are affiliated with the leading manufacturers and have extensive knowledge of the design of particle counters. Others are experienced in calibrating particle counters in their own companies. Additionally, some members are users of particle counters who rely on the results of their measurements to determine compliance or the need for corrective actions in their environments.”

Standards for calibrating particle counters have improved to address many of the areas that contribute to measurement differences between particle counters. Using standardized calibration methods can reduce these differences. The information in this RP will assist in performing the tests described in the standards that apply to particle counters.

IEST-RP-CC019.1, Qualifications for Organizations Engaged in the Testing and Certification of Cleanrooms and Clean-Air Devices, is new and was published in January 2006. Karen von Holtz is chair of this WG. This RP defines recommended qualifications for organizations engaged in the testing and certification of cleanrooms, clean-air devices, HEPA- and ULPA-filtered systems, and associated components. The document also establishes professional categories for personnel performing testing and levels of competence to be demonstrated. According to Keith Flyzik, WG-CC019 member, this document was cooperatively written by a diverse group of industry experts composed of certification organizations, test equipment manufacturers, cleanroom operators, and independent consultants specializing in the regulated cleanroom and filtration industries. This RP is invaluable to auditors, inspectors, quality assurance personnel and purchasing groups involved in the selection and evaluation process of certification organizations. It provides a wealth of knowledge on specific and essential quality, safety, calibration, and training processes/programs that certification organizations should have in place and in use.

IEST-RP-CC027.2, Personnel Practices and Procedures in Cleanrooms and Controlled Environments, is revised and was published in April 2006. This RP provides a basis for establishing personnel procedures and developing training programs for cleanrooms and other contamination controlled environments. It serves as a guide to managing contamination caused by or associated with people, processes and tooling. Chair Gary Knoth reconvened the WG in 2005 to review the RP, at which time it was decided that a rewrite was needed. Many members of the original WG participated and several new members joined the rewriting effort. The rewrite added clarification to several key sections and expanded the section on “Exiting the Cleanroom.”

New working groups

WG-CC040, Cleaning of Equipment Surfaces in Cleanrooms and Controlled Environments, is a new WG chaired by Dianne Knitter. Its scope is to provide a framework for developing an effective program for cleaning of equipment surfaces in cleanrooms and other controlled environments. This document will be beneficial to the industry by providing structure and recommendations for myriad cleaning techniques. While focusing on equipment surfaces, it will support the RPs for cleanroom housekeeping (IEST-RP-CC018.3, Cleanroom Housekeeping: Operating and Monitoring Procedures) and microbes (IEST-RP-CC023.2, Microorganisms in Cleanroom). “The work done thus far has centered on defining the scope of the document and outlining the document in detail. Assignments have been given to WG members and we are in the process of gathering information to develop the document further at the 2006 IEST Fall Conference,” says Knitter.

WG-CC041, Recovery from Disruption to Cleanrooms and Other Controlled Environments, is a new WG chaired by Mike Dingle. Its scope is to provide the framework for restoring a controlled environment to its normal operating condition in the event of a planned or unplanned disruption. “Responding to a disruption in a cleanroom or other controlled environment can have a significant impact on business,” says Dingle. “That impact can be exacerbated if a plan for how to respond to such events has not been established.” This WG plans to establish an RP that can guide users in minimizing the impact of these events. The group has thus far defined the scope of the future document, identified categories of disruptions, and developed an outline for how these different types of disruptions will be addressed.

To obtain more information about these and other recommended practices and working groups, contact IEST at (847) 255-1561 or via e-mail at [email protected], or go to the IEST Web site:


The author wishes to thank David Chandler, David Crosby, Mike Dingle, Keith Flyzik, Dianne Knitter, Gary Knoth and Karen von Holtz for their help in the preparation of this article and their leadership as IEST WG officers.

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Jim Ohlsen is director of the Materials Characterization Group at Entegris, Inc. where he is responsible for three global materials technology laboratories and one technology characterization laboratory. In his eleven years with Entegris, his departments have developed and applied numerous methods of analysis to the measurement of molecular contamination in polymers and finished products used to transport and protect critical materials in contamination-sensitive industries such as microelectronics and data storage. He has a PhD in chemistry from Texas A&M University (College Station, TX). As an active member of IEST, Ohlsen represents Entegris. Inc. as a corporate sponsor, serves as director of Standards and Practices Committee 3: Procedural and as a reviewer for the Editorial Board of the Journal of the IEST. He has presented three tutorials on IEST-RP-CC031.1, Method for Characterizing Outgassed Organic Compounds from Cleanroom Materials and Components. He serves as vice chair of WG-CC031, which published the RP in 2003.

About IEST

Founded in 1953, IEST 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-developing organization; Secretariat of ISO/TC 209, Cleanrooms and associated controlled environments; Administrator of the ANSI-accredited US TAG to ISO/TC 209; and a founding member of the ANSI-accredited US TAG to ISO/TC 229, Nanotechnologies.