Issue



Exciting news from current IEST contamination control working groups


01/01/2006







Jan Eudy, Corporate Quality Assurance Manager, Cintas Corporation, and Past President, IEST



Charles W. Berndt, C. W. Berndt Associates, Communications Vice President, IEST, and Chair, Journal of the IEST Editorial Board

Newly graduated engineers, scientists and technicians working in the contamination-control, design, test and evaluation, and product reliability industries are discovering that many of the procedures and processes for maintaining international compliance and quality assurance are found in the standards and recommended practices written by the current industry professional volunteers in the IEST working group meetings.

IEST has instituted a program of standards and practices in order to publish and disseminate up-to-date, reliable, technical information within each of its divisions: Contamination Control; Design, Test, and Evaluation; and Product Reliability

This is accomplished through a series of standards and recommended practices (RPs) providing standardized procedures based upon peer-approved applications of environmental technology. IEST’s procedures for the development of standards and RPs are in accordance with its status as an ANSI-accredited Standards Developer Organization (SDO). These documents are formulated by IEST working groups. IEST has also revised such Federal Standards as FED-STD-209, MIL-STD-781, MIL-STD-810, and MIL-STD-1246 (now IEST-STD-1246D).

Because of their quality and timeliness, many of the IEST recommended practices are primary references for the ISO 14644 series of international standards for cleanrooms and associated controlled environments. Also, several of the industry representatives who wrote the IEST recommended practices represented the United States as working group delegates for writing the ISO 14644 standards.

For example, using IEST recommended practices CC-018 Cleanroom Housekeeping and CC-026 Cleanroom Operations in conjunction with ISO 14644-5 Cleanrooms and Associated Controlled Environments-Operations can give specific insights and greater depth of understanding to users of the ISO document.

In addition, IEST conducts tutorials at its annual technical meeting (ESTECH), its Fall Conference, and online to assist its industries to better understand and effectively utilize IEST RPs and ISO standards.

In the last five years, the IEST has published the seven-part series of the ISO 14644 international standards as well as several revised recommended practices. The following recommended practices have been revised and published within the past three years.

WG-CC001: HEPA and ULPA Filters

This recommended practice (RP), recently revised and published in October 2005, covers basic provisions for HEPA (high-efficiency particulate air) and ULPA (ultralow 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. The buyer’s purchase order should specify the level of performance and grade of construction required. The buyer should also specify the filter efficiency required if it exceeds the basic level (99.97 percent). It should be noted that products and procedures contained in this RP may involve hazardous materials, operations and equipment. This RP does not purport to address all of the safety problems associated with its use. It is the responsibility of the user to consult and establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to use of this RP.

WG-CC002: Unidirectional-Flow Clean-Air Devices

This RP, validated in June 2004, 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-blower(s) and nonpowered terminal units with replaceable filter. It also presents recommendations for recertification under direction of the customer of devices owned by the customer.

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

This RP, revised and published in August 2003, addresses the gowning of personnel as an important aspect of cleanroom contamination control. It provides nonmandatory guidance for the selection, specification, maintenance and testing of apparel and accessories appropriate for use in nonaseptic and aseptic cleanrooms and other controlled environments.

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

This RP, revised and published in August 2004, 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.

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

This RP, revised and published in May 2003, 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.

WG-CC006: Testing Cleanrooms

This RP, revised and published in August 2004, 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. The tests evaluate and characterize the overall performance of the cleanroom or clean-zone system. The test methods recommend test equipment requirements and testing procedures for determining performance parameters. 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. Alternative methods are not necessarily equivalent. In contractual agreements, the buyer selects the specific tests appropriate for the cleanroom under consideration. Specific acceptance limits are also defined in contractual agreements.

The test methods also may be used or adapted for periodic monitoring of cleanroom or clean-zone performance capability.

WG-CC016: The Rate of Deposition of Nonvolatile Residue in Cleanrooms

This RP, published in November 2002, provides a uniform method of testing and basis for defining the rates of deposition of nonvolatile residue (NVR) and other forms of molecular contamination on surfaces in cleanrooms.

WG-CC018: Cleanroom Housekeeping-Operating and Monitoring Procedures

This IEST RP, published in January 2002, provides guidance for maintaining a cleanroom at the level for which it was designed. This document is intended to be used as a guide for establishing appropriate housekeeping procedures. In addition, test procedures are provided for use in establishing the frequency and monitoring the effectiveness of the housekeeping. The test methods also are designed to help determine appropriate levels of surface cleanliness for specific cleanrooms.

WG-CC021: Testing HEPA and ULPA Filter Media

This RP, published in September 2005, discusses test methods for physical and filtration properties of high-efficiency particulate air (HEPA) and ultralow penetration air (ULPA) filtration media. Application of this RP is by mutual agreement between the buyer and the seller. Use of this RP should be applied but not be limited to (a) acceptance criteria for test methods; (b) test aerosol and particle size; and (c) test face velocity.

WG-CC022: Electrostatic Charge in Cleanrooms and Other Controlled Environments

This RP, published in January 2004, discusses methods for specifying and evaluating the effectiveness of techniques for controlling electrostatic charge. Controlling electrostatic charge reduces surface contamination and electrostatic discharge. This document describes methods of testing, provides guidelines for verifying charge neutralization and resistivity of surfaces and materials, and describes typical control systems and their applications.

WG-CC026: Cleanroom Operations

This RP, published in July 2004, provides guidance for maintaining the integrity of the cleanroom during ancillary operations. Ancillary operations include preparation of supplies and materials; modification of the facility; and installation and repair of equipment. Procedures are given for verifying the cleanliness of the equipment, the workstation and the area after these ancillary operations are completed.

WG-CC028: Minienvironments

This RP, published in August 2002, is intended to stimulate discussion of specifications and configurations for a specified application between the supplier and customer. The purpose of this document is to provide a framework for describing minienvironments for microelectronics and similar applications. Applications, planning, design and evaluation are discussed in detail. This recommended practice does not address microbiological issues or applications.

WG-CC029: Contamination Control Considerations for Paint-Spray Applications

This RP, validated in June 2004, provides guidelines and recommended procedures for controlling dirt contamination (particles, fibrous material, etc.) in controlled environments used for paint spraying.

WG-CC031: Outgassing Performance Criteria for Cleanroom Materials

This RP, published in April 2003, describes a test method appropriate for semiqualitative characterization of organic compounds outgassed from materials or components exposed to air in cleanrooms or other controlled environments. This RP specifies four outgassing temperatures-50°C (122°F), 75°C (167°F), 100°C (212°F), and 150°C (302°F)-to baseline cleanroom materials and components. The RP may become the basis of an agreement between customer and supplier in the specification, procurement and certification of materials.

WG-CC034: HEPA and ULPA Filter Leak Tests

This RP, published in June 2005, covers definitions, equipment and procedures for leak-testing HEPA and ULPA filters in the factory as they are produced, at the job site before they are installed, and after they are installed in cleanrooms and unidirectional-flow clean-air devices. When used in conjunction with other RPs (IEST-RP-CC001, IEST-RP-CC002, IEST-RP-CC006, IEST-RP-CC007, or IEST-RP-CC021), it may be used to define the basis of an agreement between customer and supplier in the specification and procurement of HEPA and ULPA filters, and in the certification testing of unidirectional-flow clean-air devices and cleanrooms. This RP also includes procedures for measuring the uniformity of the aerosol challenge approaching the filter under test.

WG-CC901: IEST-STD-CC1246D: Product Cleanliness Levels and Contamination Control Program

This standard, published in October 2001, provides a basis and a uniform method for specifying product cleanliness levels and contamination-control program requirements. The emphasis is on contaminants that can impact product performance.

WG-CC902

MIL-HDBK-406: Contamination Control Technology: Cleaning Materials for Precision Pre-Cleaning and Use in Cleanrooms and Clean Work Stations; MIL-HDBK-407: Contamination Control Technology: Precision Cleaning Methods and Procedures

This standard specifies the cleaning procedures for achieving the product cleanliness levels specified in IEST-STD-CC1246D.

The dedicated volunteer IEST members are continually meeting with working group members to finalize, vote and publish the following recommended practices within the next year:

WG-CC007: Testing ULPA Filters

This RP covers production testing of filters for particle penetration and pressure drop of ultralow 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 ultralow 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 μm to 0.2 μm.

WG-CC008: Gas-Phase Adsorber Cells

This RP covers the design and testing of a modular gas-phase adsorber cell for use in once-through or recirculating air cleaning systems where high-efficiency removal of gaseous contaminants is a requirement. This practice covers two types of modular cells.

WG-CC011: A Glossary of Terms and Definitions Relating to Contamination Control

This compendium, maintained on the IEST Web Board for all members to access, controls the language and definitions of terms used in all the recommended practices for consistent, concise, clear communication of concepts in each document.

WG-CC012: Considerations in Cleanroom Design

Subgroup 1: Cleanroom Design Considerations; Subgroup 2: Installation of Cleanroom Production Equipment; Subgroup 3: Cleanroom Electrical Systems

This RP makes recommendations regarding factors to consider in the design of cleanroom facilities. This discussion is limited to those environmental conditions that typically confront cleanroom designers and users.

WG-CC013: Procedures for the Calibration or Validation of Equipment

This RP covers definitions and procedures for calibrating instruments used for testing cleanrooms and clean-air devices, and for determining intervals of calibration.

WG-CC014: Calibrating Particle Counters

This RP provides a universally recognized procedure for calibrating particle counters. Many of the IEST recommended practices and ISO standards establish particle limitations for air, liquids and surfaces. It is imperative that the particle counters in India, China, the U.K. and U.S. are calibrated similarly to accurately evaluate the data generated.

WG-CC019: Qualifications for Organizations Engaged in the Testing and Certification of Cleanrooms and Clean-Air Devices

This RP, to be published in 2006, defines (a) qualification standards for certification agencies that test unidirectional (laminar-flow) clean-air devices, cleanrooms, HEPA- and ULPA-filtered systems and associated components; and (b) criteria to be used in qualifying personnel of certification agencies. This RP establishes (1) professional categories of personnel who do testing, each category consisting of recommended minimal requirements for education, training and experience, all of which should be verified by the certification agency; and (2) the levels of competence to be demonstrated by the personnel.

WG-CC020: Substrates and Forms for Documentation in Cleanrooms

This RP, to be published in 2006, applies to substrates and forms used in cleanrooms for the purpose of documentation. Specifically included are: copy paper, writing paper, labels, tags, self-adhesive notes, perforated and punched forms, envelopes, bound materials, and all printed versions thereof. This RP provides appropriate methods for assessing the cleanliness of these items insofar as their suitability for use in cleanrooms is concerned.

WG-CC023: Microorganisms in Cleanrooms

This RP, to be published in 2006, provides guidelines for the control and quantitative measurement of viable contamination in the air and on surfaces in environments that require control of such contamination, including an introduction to the methods and devices currently available for the quantification of airborne and surface viable contamination. This document also describes some of the disinfectants currently available, their lethality spectrum, and techniques for their application.

WG-CC024: Measuring and Reporting Vibration in Microelectronics Facilities

Equipment used in the manufacture, measurement and inspection of integrated circuits is sensitive to vibration and sound. It is therefore necessary to establish levels of vibration sensitivity for them and to ensure that vibrations occurring in the facility or at the site at which they are located are below those levels. Such equipment will be referred to as process tools in this RP, which is intended to provide guidance for use in the microelectronics industry. However, it may also be applicable in pharmaceutical and biological research, metrology laboratories, and other contexts in which vibration control is important. This RP provides guidelines for conducting vibration measurements and reporting vibration data, specifically for: (a) selecting suitable instrumentation and hardware for use in vibration measurements; (b) establishing sensitive process-tool vibration thresholds; (c) conducting vibration measurements on sites and in facilities; and (d) reporting results of vibration measurements in a uniform and consistent format.

WG-CC025: Evaluation of Swabs Used in Cleanrooms

This RP, to be published in 2006, describes methods for testing swabs used in cleanrooms and other controlled environments for characteristics related to both cleanliness and function.

WG-CC027: Personnel in Cleanrooms

This RP, currently being reviewed, provides a basis for establishing personnel procedures and practices and the development of training programs for operators in cleanrooms and associated environments. Subject areas include:

  • hiring
  • training/compliance
  • hygiene/health
  • gowning system management, including gowning and behavior of cleanroom personnel
  • storage/change room
  • exiting/evacuation
  • monitoring/auditing for effectiveness

Additionally, working groups have met to create new recommended practices as the contamination-control industry evolves internationally. New recommended practices to be published in 2006 are:

WG-CC032: Packaging Materials for Cleanrooms

This RP is intended to define required characteristics and test methods for evaluating flexible packaging for cleanroom products and supplies destined for use in controlled environments. Methods include, but are not limited to, cleanliness level and mechanical and chemical characteristics. In addition, this RP provides information related to the properties, performance characteristics, and usage issues for flexible-packaging materials in order to prevent contamination of product/device due to molecular contamination as a result of leachables, extractables and NVRs or other diffusion processes. These guidelines may be used to establish agreement between the supplier and the customer for specification, procurement and certification testing of clean flexible-packaging material. This RP includes particle cleanliness level and material properties as they pertain to outgassing and endurance of flexible-packaging material.

WG-CC035: Design Considerations for Airborne Molecular Contamination Filtration Systems in Cleanrooms

This RP describes important areas of concern when considering airborne molecular contamination (AMC) filtration systems. It discusses various applications, potential points of use, filtration methods, materials of construction, performance comparison and follow-up assessment, secondary impacts of the filters on the rest of the HVAC system, and exterior impacts on the filtration system (including environmental conditions, upsets, spills, etc.). It establishes the type of information required to design and implement an effective AMC filtration system. Although this document is targeted at cleanroom facilities, it could form a framework for other applications as well.

WG-CC036: Testing Fan Filter Units

This RP covers the methods and definitions for testing the performance of fan filter units. Its purpose is to provide customers and suppliers of fan filter units the necessary test protocols for measuring performance in such a matter as to allow direct comparison of units provided by different manufacturers of varying designs and operating features. The test methods identify test equipment and testing procedures necessary to measure volumetric airflow, electric power parameters (watts, amps, voltage, and power factor), available external static pressure, sound pressure levels, sound power levels, filter air velocity uniformity, and housing vibration. These procedures are applicable for units with AC motors, with DC brushless motors, without constant airflow control, or with constant airflow control. These procedures are applicable to fan filter units with filter airflow dimensions less than or equal to four feet in any direction.

In the working group WG-CC101: Forum on Air Cleanliness Technology, a “think tank” of contamination-control professionals assembles to propose the formation of working groups on innovative topics. Three new working groups met at the IEST Fall Conference in November 2005:

  • Nano Facilities Design, Manufacturing, Operations and Product Testing
  • Methods for Cleaning Cleanrooms and Equipment
  • Disruption Plan Following Disasters

The United States has been and continues to be the international leader in technology and development. Exciting discussions and debates in the working group meetings formalize the IEST recommended practices and ISO international standards. If you are interested in actively participating in an IEST working group, we welcome you to observe a working group meeting during ESTECH or the IEST Fall Conference. Please visit the IEST Web site at www.iest.org for further information.

One or a set of the IEST recommended practices or the ISO 14644 series of international standards can be purchased at the IEST Web site. Be the first in your industry to own the most recent versions of these recommended practices and/or international standards.

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Jan Eudy is the corporate quality assurance manager for Cintas Corporation. At Cintas, she oversees research and development, directs the quality system and ISO registration at all cleanroom locations, and supports validation and sterile services. She established and implemented the HACCP program at Cintas. She is the Past President of the Institute for Environmental Sciences and Technology and an active member of other professional organizations, including the American Society of Clinical Pathologists, the National Registry of Microbiology, the American Society for Microbiology, the American Society for Quality, the International Society for Pharmaceutical Engineers, and the Parenteral Drug Association. Eudy represents Cintas on the FPA Advisory subcommittee to the FDA for the revision of the Food Processing cGMPs. She graduated with a degree in medical technology from the University of Wisconsin with graduate studies in medical microbiology at Creighton University. Her additional qualifications include Registered Medical Technologist and Specialist in Microbiology with ASCP, Registered Microbiologist with NRM in Consumer Product Testing and Quality Assurance, ISO 9000 Lead Assessor and Certified Quality Auditor with ASQ.

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Charles W. Berndt is the principal in C. W. Berndt Associates, Highland Park, Illinois, which provides advisory services associated with human-sourced contamination control. He spent eight years as group manager of the Araclean Division of ARA/Aratex Services (now known as ARAMARK Cleanroom Services). He serves on the Editorial Advisory Board of CleanRooms magazine, chairs the Editorial Board of the peer-reviewed Journal of the IEST, is Communications Vice President of IEST, and serves on IEST’s Executive Board. He chaired Working Group CC-003 during the development of IEST-RP-003.3. He currently chairs IEST Working Group CC-029, Contamination Control Considerations for Paint Spray Applications. He is the recipient of the 2001 Willis J. Whitfield Award presented “for substantial contributions to the field of contamination control through published papers, studies and reports” and the 2004 Monroe Seligman Award “for his diligence and perseverance in carrying out the mission of the Journal of the IEST.” Both awards were presented by IEST.

ABOUT IEST

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 the Secretariat for ISO Technical Committee 209, Cleanrooms and associated controlled environments, charged with writing a family of international cleanroom standards. IEST is also an ANSI-accredited standards-development organization. For more information, contact IEST at iest@iest.org or visit the IEST Web site at www.iest.org.