This paper written by Mark Hallworth, one of the ISO TR 14644 21 committee members, discusses why this new technical report was released, the implications, and next steps for practical application. Complete with explanatory diagrams and a decision tree.
Understanding particle counter counting efficiency helps you to identify the best solution for your application and understand the data from the particle counter.
All non-volumetric particle counters have sample volume growth to some degree, which results in a lower particle counting efficiency at the lower limit of detection and variable particle counting efficiency across the lower channel sizes. This increase in particle counting efficiency with particle size means the counting efficiency measured at a single particle size in this channel cannot be applied to the entire channel. Use of the particle counting efficiency as a correction factor does not result in “true” particle counts.
The purpose of the Growth Promotion Test (GPT) is to determine the appropriateness of the culture media to be used in environmental monitoring sampling. The medium is challenged with a small number of microorganisms to assure the nutritive properties, functionality and media quality are adequate for the detection and enumeration of microbial contaminants.
Understanding critical air patterns and their impacts is paramount to controlling an environment and is a crucial activity in adhering to the relevant regulations. Scientific demonstration is the basis of pharmaceutical GMP regulatory compliance, and the best way to demonstrate air patterns is through airflow visualization studies (also known as smoke studies). If unidirectional airflow (UDAF) is used as a tool for mitigating the risk of contamination, a company must demonstrate its effectiveness through such studies.