Clean spaces and similar controlled environments - Part 12: Classification of air purity by nanoscale particle concentration

This part of ISO 14644 covers the classification of air cleanliness by particles (ACP) in terms of concentration of airborne nanoscale particles. For classification purposes, only populations of particles with a lower size limit of 0.1 microns (100 nm) or less - "nanoscale" - are considered. The classification given in this document is for use mainly in "in operation" states. This classification extrapolates the particulate classification equation specified in 14644-1 into the nanoscale (<100 nm) region.