ISO 14644-1: Classification of Air Cleanliness by Particle Concentration

ISO 14644-1 is the foundational cleanroom standard — defining the nine ISO cleanroom classes and specifying the particle count testing methodology used to classify and verify cleanroom performance.

What It Requires:

Classification of your cleanroom by particle count testing at defined locations, using the statistical sampling plan specified in the standard. Testing must be performed at rest and in operation. Results must demonstrate that particle concentrations at each measurement location and for each particle size do not exceed the limits specified for your ISO class.

Classification Limits — Key Classes:

Requalification Frequency:

ISO Class 5 and cleaner — every 6 months. ISO Class 6 and above — every 12 months. More frequent monitoring may be required by applicable GMP guidelines.