ISO 14644-1 Cleanroom Standards


ISO 14644-1 Cleanroom Standards

Class Maximum Particles/m3 FED STD 209E Equivalent
>0.1 um >0.2 um >0.3 um >0.5 um >1 um >2 um
ISO 1 10 2
ISO 2 100 24 10 4
ISO 3 1,000 237 102 35 8 Class 1
ISO 4 10,000 2,370 1,020 352 83 Class 10
ISO 5 100,000 23,700 10,200 3,520 832 293 Class 100
ISO 6 1,000,000 237,000 102,000 35,200 8,320 2,930 Class 1,000
ISO 7 352,000 83,200 29,300 Class 10,000
ISO 8 3,520,000 832,000 293,000 Class 100,000
ISO 9 35,200,000 8,320,000 2,930,000 Room Air


What is an ISO Cleanroom Rating?

The International Standards Organization creates ISO ratings. It is a worldwide federation of national standards that partners with internal organizations, government agencies, and non-governmental organizations to establish technical performance standards and recommended practices.

What is an ISO 14644-1 Cleanroom Classification?

Achieving an ISO-rated cleanroom environment involves adhering to the ISO 14644-1:2015 standard, which guides designing structures, testing, and calibration. Depending on the task and cleanroom rating, additional features and enclosures may be necessary to ensure isolation, containment, or safe exfiltration of potential hazards, chemicals, aerosols, and particulates. The standard includes requirements for contamination control and risk-mitigating strategies such as health and safety, compatibility with cleaning agents and techniques, cleanability, biocontamination, specific equipment and material needs, and design details.

What Are the ISO Cleanroom Classes for a Cleanroom?

Cleanrooms are categorized based on strict standards that determine their level of cleanliness, known as a “rating.” The rating is assigned between ISO Class 1 and ISO Class 9 based on the number of particles per cubic meter of air. In the US, cleanrooms are usually rated between ISO Class 3 and ISO Class 8, with lower ratings indicating a cleaner environment.

An uncontrolled environment can contain millions or even billions of particles per cubic meter, making it far less clean than a clean room. For example, an ISO 8 cleanroom reduces airborne particulate by a factor of 10 compared to a typical office environment, meaning that each cubic meter of air sampled must contain fewer than 100,000 particles. With each increase in ISO class, air quality improves by a factor of 10.