Howard F. Fortescue Ltd. is registered in
HFF has more than 25 years experience in the Optical Disc Industry.
Cleanroom Classification
Explained
US FED STD 209E was canceled November 29, 2001, and was replaced by ISO 14644, however the old classifications [Class 100 etc] are still in common use. These tables are only intended as a guide to the equivalence between the two standards.
The two columns on the far right show the values from the ≥ 0.5 µ column multiplied by the number of cubic feet in a cubic metre. (~35.3) When these are rounded you can see that they give the old classification classes (last column).
