Cleanroom Classification Tables

Discover the different classes within the cleanroom ISO standards and their Federal Standard and GMP equivalent. These tables detail the air changes and particle counts that define each class. 

Air Changes by Cleanroom Classification

This table details the required air changes per hour for ISO 14644-1:2015 cleanrooms and their associated GMP Grade and Federal Standard.
Cleanroom StandardCleanroom Classification Guidelines
ISO 14644-1 Class 3 Class 4 Class 5 Class 6 Class 7 Class 8
Federal Standard 209E 1 10 100 1,000 10,000 100,000
EU GMP - - A/B - C D
Air changes / hour 360-540 300-540 240-480 150-240 60-90 5-48

For cleanrooms and clean zones.

ISO 14644-1:2015 Cleanroom Classification

This table details the air cleanliness class by particle concentration.
ISO Classification NumberMaximum allowable concentrations (particles/m3) for particles equal to and greater than the considered sizes, shown below
≥0.1µm ≥0.2µm ≥0.3µm ≥0.5µm ≥1µm ≥5.0µm
ISO Class 1 10b d d d d e
ISO Class 2 100 24b 10b d d e
ISO Class 3 1,000 237 102 35b d e
ISO Class 4 10,000 2,370 1,020 352 83b e
ISO Class 5 100,000 23,700 10,200 3,520 832 d,e,f
ISO Class 6 1,000,000 237,000 102,000 35,200 8,320 293
ISO Class 7 c c c 352,000 83,200 2,930
ISO Class 8 c c c 3,520,000 832,000 29,300
ISO Class 9g c c c 35,200,000 8,320,000 293,000

For cleanrooms and clean zones shown in ISO 14644-1:2015

Cleanroom Limits for Airborne Particulate Contamination

Clean room and clean air device classification, in relation to GMP (2008).
Cleanroom StandardMaximum permitted number of particles /m³
EU GMP Grade ISO EN 14644-1 At rest ≥0.5µm At rest ≥5.0µm In operation ≥0.5µm In operation ≥5.0µm
A 5 3,520 20 3,520 20
B 5 3,520 29 352,000 2,900
C 7 352,000 2,900 3,520,000 29,000
D 8 3,520,000 29,000 Not defined Not defined

For cleanrooms and clean zones


Related articles

ISO 14644-1 Class 5 Cleanroom Classification guidelines

Hardwall and monobloc cleanroom constructions are most effective at achieving the environment requir...

Read more

ISO 14644-1 Class 6 Cleanroom Classification Guidelines

ISO Class 6 Cleanrooms are typically hardwall or monobloc construction and often utilise HEPA filtra...

Read more

ISO 14644-1 Class 7 Cleanroom Classification Guidelines

ISO Class 7 Cleanrooms typically use HEPA filters and can be constructed as Softwall, Hardwall or Mo...

Read more