ISO 14644-1:2015 classifies air cleanliness for airborne particle population levels (ranging from 0,1 µm to 5 µm, lower-limit threshold) in cleanrooms and clean zones; and separative devices – in addition to those defined in ISO 14644‑7.
How often a cleanroom be validated to meet ISO 14644-1:2015?
ISO 14644-1:2015 states the maximum time interval between airborne particle concentration testing of a cleanroom of ISO class 5 and below is six months and ISO class 6 and above is 12 months.
| Test Parameter | Class | Maximum Time Interval |
| Airborne particle concentrations | = ISO Class 5 | 6 months |
| >ISO Class 5 | 12 months | |
| Schedule of additional tests | ||
| Airflow velocities in unidirectional airflow | All classes> | 6 months |
| Airflow volume supply in non-unidirectional airflow | All classes | 12 months |
| Pressure differentials | All classes | Continuously monitored |
Source: cleanroomtechnology.com
Highlights of ISO 14644-1:2015:
- In ISO 14644-1:2015, particle populations ranging from 0,1 µm to 5 µm (less than the lower-limit threshold) are considered for classification purposes.
- Classification is not provided for particle populations outside of the particle population range of lower threshold particle-size range, 0,1 µm to 5 µm.
- Light scattering airborne particle counters (LSAPC) are used to identify and count airborne particles that fall within the outlined size threshold in this chapter.
- ISO 14644-1:2015 does not classify molecule populaces that are outside the predefined lower limit molecule size reach, 0,1 µm to 5 µm. Convergences of ultrafine (particles littler than 0,1 µm) will be tended to in a different standard to determine air cleanliness by nano-scale particles. A M descriptor (see Annex C) might be utilized to measure populaces of macroparticles (particles bigger than 5 µm).
- Chemical, physical, radiological, viable or identifying features of airborne particle are not characterized in ISO 14644-1:2015