Understanding ISO 14644-1 Class 5 and Its Replacement of Fed Spec 209e

First published in 1963, US Federal Standard 209E, which dealt with cleanroom classification and monitoring, was also used for several years by other nations. The European Committee for Standardization (CEN) worked with the International Organization for Standardization (ISO) to develop standards to be used by all of Europe, though each member nation had their own national standards as well. The need for a single standard for cleanroom classification and testing by which regulatory agencies and (multinational) companies around the world would comply was long felt, but it was never fully realized until 1992, when the American National Standards Institute (ANSI), backed by the Institute of Environmental Sciences and Technology (IEST) petitioned ISO to develop an international standard that would be used on a global scale.

To that end, ISO formed Technical Committee (TC) 209 and began developing standards for cleanroom classification and monitoring that are now known as ISO 14644 and 14698. Seven years later, ISO/TC 209 saw IEST publish ISO 14644-1, the first international standard to deal with cleanliness classifications. ISO 14644-2 was published in 2000 and discussed the monitoring procedures required to remain compliant with ISO 14644-1.

ISO 14644-1 titled:

"Cleanrooms and associated controlled environments -Part 1-Certification of air cleanliness document" was formally issued in 1999. This document establishes the certification requirements for air cleanliness areas. This document has replaced the old Fed Std. 209-e (class 100, 10,000 and 100,000 designations.) Within this document the various classification systems are based upon the requirements for counts associated with non -viable particulates. The limits stated in the document are shown in our table below: This document and table indicate that ISO 5 particle concentration is equal to class 100 and approximately equal to EU Grade A. However the microbiological limits in this document are only applicable to aseptic processing. ISO5, Class 100 and EU Grade A are normally considered to be arbitrarily equal to each other for purposes of general certification. of interest to the Pharmaceutical industry is that this classification system does not show any specified limits for viable micro organisms that may be present. For information on micro biological contamination limits and test results, you should refer to the European Unions GMP Annex 1 and Annex 2.

In U.S. manufacturing it is very important that you understand the implications of the classification systems that you use for packaging your finished products, and that you use them wisely.

Summary Table: ISO Vs. FS 209E
Affected Parameters	FS 209E	ISO 146441-1
Number of Cleanliness Classes	6	9
Class Designations	1 - 10000	1 - 9
Measurements Taken in	Feet	Meters
Sample Time Minutes	> 1 Minute for Smaller Particle Sizes	1 Minute Minimum for All Particles

The differences between FS209E and ISO 14644 are the addition of 3 more cleanliness classes, new class designations, and the use of the metric system in calculating both the minimum volume of air and the dimensions of the test area. In general, fewer sample locations are required when following ISO 14644, though the required minimum sample time of one minute is longer than that for FS209E. Finally, per ISO 14644, the cleanliness classes are now calculated, a standard particle size (1.0µm) has been added, and there are guidelines for establishing periodic testing schedules.

Class Designations
FS209E English	ISO 14644-1
-	1
-	2
1	3
10	4
100	5
1000	6
10,000	7
100,000	8

European nations declared their own standards superseded by Parts 1 and 2 of ISO 14644 six months after the publication of each document, and the US reached that same conclusion in November 2001 when it declared FS 209E “cancelled and superseded”. However, there are still numerous companies in the United States that have not yet begun using the now-current standards.