ISO 14644-1
Cleanrooms and associated controlled environments
Part 1: Classification of air cleanliness by particle concentration
ISO 14644-1 is the primary international standard for classifying air cleanliness in cleanrooms and controlled environments, primarily based on the concentration of airborne particulates. It defines 9 classes (ISO 1–9) based on particle sizes (0.1 µm to 5 µm), replacing the old US Federal Standard 209E with modern metrics.
What is a Cleanroom?
A cleanroom is a controlled environment that regulates airborne particles, temperature, humidity, and pressure to maintain specific cleanliness levels. They are commonly used in industries like pharmaceuticals, semiconductors, aerospace, and medical device manufacturing.
The Two Main Classification Systems The U.S. has used two primary cleanroom classification systems over the years:
The older Federal Standard 209E (FS 209E) classified cleanrooms using Class ratings based on the number of particles per cubic foot of air. This system was officially cancelled in 2001 but is still widely referenced in American industry today.
The current international standard, ISO 14644, classifies cleanrooms on a scale of ISO 1 through ISO 9 based on particles per cubic meter.
How the Two Systems Compare
| Federal Standard 209E (Class) | ISO 14644 (ISO Class) |
|---|---|
| Class 1 | ISO 3 |
| Class 10 | ISO 4 |
| Class 100 | ISO 5 |
| Class 1,000 | ISO 6 |
| Class 10,000 | ISO 7 |
| Class 100,000 | ISO 8 |
Common Industry Applications by Class
- Class 1 / ISO 3-4 — Semiconductor and microelectronics manufacturing
- Class 100 / ISO 5 — Pharmaceutical aseptic processing and hospital operating rooms
- Class 1,000 / ISO 6 — Medical device manufacturing and biotech labs
- Class 10,000 / ISO 7 — General pharmaceutical and biotech manufacturing
- Class 100,000 / ISO 8 — General pharmaceutical manufacturing and food processing
Abstract
ISO 14644-1:2015 specifies the classification of air cleanliness in terms of concentration of airborne particles in cleanrooms and clean zones; and separative devices as defined in ISO 14644‑7.
Only particle populations having cumulative distributions based on threshold (lower limit) particle sizes ranging from 0,1 µm to 5 µm are considered for classification purposes.
The use of light scattering (discrete) airborne particle counters (LSAPC) is the basis for determination of the concentration of airborne particles, equal to and greater than the specified sizes, at designated sampling locations.
ISO 14644-1:2015 does not provide for classification of particle populations that are outside the specified lower threshold particle-size range, 0,1 µm to 5 µm. Concentrations of ultrafine particles (particles smaller than 0,1 µm) will be addressed in a separate standard to specify air cleanliness by nano-scale particles. An M descriptor (see Annex C) may be used to quantify populations of macroparticles (particles larger than 5 µm).
ISO 14644-1:2015 cannot be used to characterize the physical, chemical, radiological, viable or other nature of airborne particles.
ISO Standards Video:
To see more content about ISO Standards Click Here.