Whitepaper: Changes to GMP force cleanroom re-classifications

This whitepaper discusses the ISO 14644-1:2015 revisions impacting both the way the cleanrooms are classified and air particle counting instruments…

According to both USA cGMP¹ and EU GMP² cleanroom classification should be carried out according to ISO 14644-1.

The 19994 version of this ISO standard has been re-written by a group of international subject matter experts and ISO 14644-1:2015⁶ was published on December 15, 2015. ISO 14644-1:2015 contains substantial revisions impacting both the way the cleanrooms are classified and the performance requirements of the air particle counting instruments used to carry out the classification. Cleanroom users claiming compliance to cGMP and/or GMP will have to consider these new rules when next re-qualifying their cleanrooms, potentially purchasing new air particle counters if their existing counters do not comply with the new performance rules and facing the dilemma that the new re-qualification may indicate that their cleanroom is not operating at the grade they had achieved using the old classification process. This paper explains the new rules.

Although EU GMP and USA cGMP both define the airborne particle counts/m³ for each cleanliness class/grade, they do not contain guidance on the cleanroom classification procedure. Instead they point the reader to ISO 14644-1 for the cleanroom classification methodology. As part of the routine periodic review process, the ISO committee responsible for ISO 14644-1 decided that areas of the classification process required revision to improve statistical accuracy. At the same time, the ISO committee decided to add a reference in the normative Annex on airborne particle counters to ISO 21501-4⁵, which provides a calibration procedure and verification method for particle counters, intended to minimize the inaccuracy in the measurement result by a counter, as well as the differences in the measured results from different particle counters. The stringent performance rules in ISO 21501-4 mean that many older air particle counters are no-longer suitable for cleanroom classification/re-qualification according to ISO 14644-1.