The Federal Standard 209E
The Federal Standard 209E “Airborne Particulate Cleanliness Classes in Cleanrooms and Cleanzones” graded cleanrooms as “Class 1/10/100/1000/10000/100000”.
FED-STD-209E was discontinued in 2001 and superseded by the ISO standard. However, this standard is retained on many standard comparison tables to maintain consistency between older and newer facilities.
Air Changes by Cleanroom Classification
|Cleanroom Standard||Cleanroom Classification Guidelines|
|ISO 14644-1||Class 3||Class 4||Class 5||Class 6||Class 7||Class 8|
|Federal Standard 209E||1||10||100||1,000||10,000||100,000|
|Air changes / hour||360-540||300-540||240-480||150-240||60-90||5-48|