ISORegulatory IntelligenceStandard
ISO 14644-1

Cleanrooms and Associated Controlled Environments — Classification of Air Cleanliness by Particle Concentration

Establishes the classification of air cleanliness in terms of concentration of airborne particles in cleanrooms and clean zones. Defines ISO Classes 1–9 with associated particle concentration limits and classification testing protocols.

LAST REVISED
December 2015
PRODUCT AREAS
Sterile
SCOPE & APPLICABILITY

All cleanroom operators in pharmaceutical, semiconductor, aerospace, and other critical manufacturing industries. Provides the universal basis for cleanroom classification referenced by EU GMP, FDA, and national regulations.

KEY REQUIREMENTS
  • 01Particle counter calibration and performance verification before classification testing
  • 02Minimum number of sampling locations calculated from cleanroom area using Table 1
  • 03Sampling volumes at each location sufficient to detect 20 particles at the class limit (U95)
  • 04Statistical analysis (95% Upper Confidence Limit) of data
  • 05Classification report with all data, calculations, and deviations noted
IMPLEMENTATION TIPS
EU GMP requires both at-rest and in-operation classification — document which state each result represents
Particle counters must be calibrated to ISO 21501-4 — confirm your calibration certificate references this
Create a classification map showing all sample locations with distances to walls and process equipment
REVISION NOTES

Current version December 2015 — revised from 1999 version. Sample size calculation methodology changed significantly. Verify existing classification protocols use 2015 methodology.

ISO 14644-1: frequently asked questions

Quick answers to common questions about ISO 14644-1.

What is ISO 14644-1?

ISO 14644-1 — Cleanrooms and Associated Controlled Environments — Classification of Air Cleanliness by Particle Concentration — is a standard issued by the International Organization for Standardization. Establishes the classification of air cleanliness in terms of concentration of airborne particles in cleanrooms and clean zones. Defines ISO Classes 1–9 with associated particle concentration limits and classification testing protocols.

Who does ISO 14644-1 apply to?

All cleanroom operators in pharmaceutical, semiconductor, aerospace, and other critical manufacturing industries. Provides the universal basis for cleanroom classification referenced by EU GMP, FDA, and national regulations.

What are the key requirements of ISO 14644-1?

ISO 14644-1 requires, among other things: Particle counter calibration and performance verification before classification testing; Minimum number of sampling locations calculated from cleanroom area using Table 1; Sampling volumes at each location sufficient to detect 20 particles at the class limit (U95); Statistical analysis (95% Upper Confidence Limit) of data.

When was ISO 14644-1 last updated?

The current version of ISO 14644-1 dates from December 2015. Current version December 2015 — revised from 1999 version. Sample size calculation methodology changed significantly. Verify existing classification protocols use 2015 methodology.

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