ISO 14644-1, Cleanrooms and associated controlled environments—Part 1: Classification of air cleanliness, was the first ISO 14644 International Standard prepared by ISO Technical Committee 209 (ISO/TC 209). The document was submitted as an American National Standard and has been adopted as ANSI/IEST/ISO 14644-1:1999 in the United States, following the cancellation of FED-STD-209E.
Many factors besides airborne particulate cleanliness must be considered in the design, specifications, operations and control of cleanrooms and other controlled environments. These are covered in some detail in other parts of the International Standards prepared by ISO/TC 209. ISO 14644-1 covers the classification of air cleanliness in cleanrooms and associated controlled environments. Classification in accordance with this standard is specified and accomplished exclusively in terms of concentration of airborne particles.
See also 
- ISO 14644 - standard for Airborne Particulate Cleanliness Classes in Cleanrooms and Clean Zones
- "ISO 14644-1 Scope". IEST. Last updated 2007-12-03. Retrieved 2008-01-17.