Here is the truth: The core remains the active standard. However, in 2022 , the International Organization for Standardization (ISO) released a technical Amendment (Amd 1) .
: The number of required sampling points is now determined using a fixed table based on area (sq meters) rather than the previous "square root of area" formula. iso 14644-1 pdf 2022
No. The 2022 amendment does not change your current ISO Class (e.g., Class 5 or Class 7). It simply adds a formal way to handle macroparticles . Here is the truth: The core remains the active standard
The 2015 version remains the global benchmark for classifying air cleanliness by particle concentration. It replaced the 1999 version with several critical updates: The 2015 version remains the global benchmark for
If you are using the old 1999 or 2015 standards for 5 µm monitoring without the "M" descriptor, your classification could technically be considered non-compliant with the latest ISO guidelines. The 2022 update validates what many pharma cleanrooms were already doing—testing for large particles using specialized tools.
A word of caution: Do not trust random websites offering a free PDF of this standard. ISO standards are copyrighted. The 2022 amendment is only 2 pages long (plus a cover), but it must be purchased from your national standards body.
Here is what you need to know: