After ten years of discussions and no fewer than two drafts, the two new parts 1 and 2 of ISO 14644 have just been published on the ISO website. Dated 15 December 2015, the two revised documents supersede the first editions published in 1999 (part 1) and 2000 (part 2). However, we will still have to wait for several months before the text is officially published by the European Committee for Standardization (CEN). This CEN-approved version will not contain any changes to the content of the reference document. The two ISO standards are currently available in English and French on the website iso.org and will soon be published on afnor.org.
Launched in 2005, this revision process has resulted in major changes, with a total overhaul of the scope and the technical basis of these standards.
New statistical approach
The content of ISO 14644-1 is now explicitly dedicated exclusively to the classification of cleanrooms in terms of airborne particulates. This has also meant a change to its name, which is now “Classification of air cleanliness by particle concentration”, to be consistent with the other parts of ISO 14644. The new text now includes methodological issues, specifying the tests to be carried out to determine the cleanliness classification. It is also this area that has seen the biggest changes for those responsible for controlled environments. The revision has in fact resulted in a new statistical approach, with consequences on how samples are taken, the number of locations to take samples from, and the rules for coming to a conclusion about compliance. The changes relate to the table of maximum particle concentrations allowed with the removal of limits below 10 parts/m3 as well as the limit of 29 parts/m3 for diameters equal to or greater than 5µm in ISO 5.
The structure and purpose of ISO 14644-2 have been changed significantly. In the new version, part 2 is solely focused on monitoring the performance of cleanrooms in terms of managing airborne particulate contamination, according to practical and methodological processes to be defined in the framework of the general monitoring plan. The approach is based on assessing risks to establish proof of the performance of the cleanrooms in relation to particulate contamination.
Source : www.processpropre.fr