ISO 14644-9, Classification of Surface Cleanliness by Particle Concentration
(US Title: ANSI/IEST/ISO 14644-9:2012)

ISO 14644-9, Cleanrooms and associated controlled environments - Part 9: Classification of surface cleanliness by particle concentration , may be ordered directly through IEST. ISO 14644-9 was published as an International Standard in 2012. The document was submitted as an American National Standard and has been adopted as ANSI/IEST/ISO 14644-9:2012.


This ISO document describes the classification of the particle contamination levels on solid surfaces in cleanrooms and associated controlled environments applications. Recommendations on testing and measuring methods as well as information about surface characteristics are given in informative annexes.

It applies to all solid surfaces in cleanrooms and associated controlled environments such as walls, ceilings, floors, working environment, tools, equipment, and devices. The surface particle cleanliness (SPC) classification is limited to particles between 0,05 µm and 500 µm.

The following issues are not considered in this document:

  • Requirements on the cleanliness and suitability of surfaces for specific processes
  • Procedures for the cleaning of surfaces material characteristics
  • Other characteristics of particles such as electrostatic charge, ionic charges, biological state, and others

The document covers the classification system of surface particle contamination with no reference to the interactive bonding forces or generation processes, which are usually time-dependent (such as deposition, sedimentation, aging) and process-dependent (such as transportation or handling). Measurement methods of the classification should be adapted for surface characteristics (such as porosity, roughness, electrostatic charge, surface energy, etc.). The surface cleanliness depends amongst others on material and design characteristics, on stress loads (complex of loads acting on a surface) and on the prevailing environmental conditions.

View list of ISO 14644 Standards