Revision Of Cleanroom Standards
By Dr. Tim Sandle
Regular readers of this blog will know that the main cleanroom standard: ISO 14644, is undergoing revision and that the drafts are out for public comment.
The ISO 14644 standard is made up of seven parts. The first two parts are the ones which are being revised, namely:
- ISO 14644-1 Cleanrooms and associated controlled environments: Part 1: Classification of air cleanliness by particle concentration
- ISO 14644-2 Cleanrooms and associated controlled environments: Part 2: Specifications for monitoring and periodic testing to prove continued compliance with ISO 14644-1
The most significant changes with respect to these two standards, as summarized by Tony Harrison vice-chairman of the PHSS, are:
- The Upper Confidence Limit calculation and Student ‘T' Test are removed
- The ‘square root rule' for calculating the number of sample locations for classification has been removed
- A new table has been added to determine the number of sample locations for classification according to the size of the area to be classified
- Normative reference to ISO 21501-4 is now included, making compliance with ISO 21501-4 a requirement (ISO 21501-4 provides a calibration procedure and verification method for particle counters used to classify and monitor cleanrooms)
- The Air Cleanliness Classification Table defining the maximum allowable number of particles for each ISO class has been modified. Most significantly to the pharmaceutical and healthcare industries, reference to the number of particles >5micron has been completely removed for ISO Class 5 (significant because EU GMP Annex 1 refers to particles 5micron for Grade A conditions and refers to this being equivalent to ISO Class 4.8 and, although the FDA cGMP does not refer to 5micron particles, it does refer to ISO Class 5 as being the environment for aseptic sterile manufacturing, thus implying that the area should attain the related 5micron cleanliness)
Tim Sandle, Ph.D, M.A., BSc (Hons), CBiol, MSBiol., MIScT – Dr. Sandle is the Head of Microbiology at the UK Bio Products Laboratory. Dr. Sandle is a chartered biologist and holds a first class honors degree in Applied Biology; a Masters degree in education; and obtained his doctorate from Keele University. His role involves overseeing a range of microbiological tests, batch review, microbiological investigation and policy development. In addition, he is an honorary consultant with the School of Pharmacy and Pharmaceutical Sciences, University of Manchester and is a tutor for the university's pharmaceutical microbiology M.Sc course. Dr. Sandle serves on several national and international committees relating to pharmaceutical microbiology and cleanroom contamination control (including the ISO cleanroom standards). He is currently chairman of the PharMIG LAL action group and serves on the NBS cleaning and disinfection committee. He has written over eighty book chapters, peer reviewed papers and technical articles relating to microbiology. He is currently the editor of the Pharmaceutical Microbiology Interest Group Journal and runs an on-line microbiology forum (www.pharmig.blogspot.com). Dr. Sandle is an experienced auditor and frequently acts as a consultant to the pharmaceutical and healthcare sectors.