Table I

FDA Air Classificationsa

ISO Class DesignationClean Area Classification≥0.5 μm Particles/m3Microbiological Active Air Action Levelsb (cfu/m3)
  • a All classifications are based on data measured in the vicinity of exposed materials/articles during periods of activity.

  • b Values represent recommended levels of environmental quality. You may find it appropriate to establish alternate microbiological action levels due to the nature of the operation or method of analysis.

  • c Samples from Class 100 (ISO Class 5) environments should normally yield no microbiological contaminants.