FED-STD-209E
FED-STD-209E was a United States federal standard that defined the requirements for the cleanliness of air in cleanrooms and associated controlled environments. The standard was first issued in 1963 and underwent several revisions, with the "E" version being published in 1990. FED-STD-209E was widely recognized and used in industries requiring controlled environments, such as biotechnology, pharmaceuticals, and semiconductor manufacturing, until it was superseded by international standards.
Overview
FED-STD-209E specified the levels of air cleanliness in terms of the number of particles, of a specified particle size, per cubic foot of air. The standard categorized cleanrooms into different classes based on the concentration of particles. The most common classes under this standard were Class 100, Class 1,000, Class 10,000, and Class 100,000, where the class number refers to the maximum allowable number of particles (0.5 micrometers or larger) per cubic foot of air.
Transition to ISO Standards
In the late 1990s, the International Organization for Standardization (ISO) developed a series of cleanroom standards known as ISO 14644. These standards were adopted globally and began to replace national standards, including FED-STD-209E. ISO 14644-1, in particular, specifies air cleanliness in terms of the number of particles per cubic meter, which is a departure from the cubic foot measurement used in FED-STD-209E. The transition to ISO standards was completed when the General Services Administration (GSA) officially withdrew FED-STD-209E in 2001.
Impact and Legacy
Despite its withdrawal, FED-STD-209E had a significant impact on the development and implementation of cleanroom technology. It established a framework for classifying cleanroom cleanliness that facilitated communication and standardization across different industries. The transition to ISO standards has allowed for a more consistent and universally accepted set of criteria for cleanroom classification, but the legacy of FED-STD-209E remains in the foundational concepts it established.
See Also
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