ISO 14644-12:2018 covers the monitoring of air cleanliness by particles in terms of concentration of airborne nanoscale particles.

For monitoring purposes, only populations of particles with a lower size limit of 0.1 microns (100 nm) or less - "nanoscale" - are considered.

The monitoring given in this document is for use mainly in "operational" states.

NOTE 1 For the purposes of this document, reference is made to "nanoscale particles", which means all nano-objects having one (nanoplate), two (nanofibre) or three (nanoparticle) dimensions in the nanoscale.

NOTE 2 As a consequence, the specifications for monitoring air cleanliness by nanoscale particle concentration of the cleanroom in operational state also considers process specifics, e.g., used equipment, personnel behaviour, etc.

NOTE 3 Health and safety considerations are excluded from this document.