What is Clean Room Classification?

Clean Room Classification refers to the categorization of clean rooms based on the number and size of particles allowed in the air. These classifications ensure that the air cleanliness levels are appropriate for sensitive manufacturing processes. The most widely accepted standard for clean room classification is ISO 14644-1

, which defines the allowable concentration of airborne particles based on size.

1. ISO1 Cleanroom

ISO1 is the highest classification, with stringent requirements. It allows only 1 particle

(0.5 microns or larger) per cubic meter. This level of cleanliness is typically needed for Semiconductor manufacturing, where even the tiniest particle could damage delicate components.

• Airborne particle count:

  ≤1 particle per cubic meter (0.5 microns)

• Applications:

  Semiconductor, aerospace, advanced optics

• Features:

  Advanced filtration systems, high air exchange rates

2. ISO2 Cleanroom

ISO2 modular cleanrooms are slightly less stringent than Class 1 but still offer extremely high cleanliness levels. They allow 10 particles

per cubic meter, making them suitable for critical manufacturing processes where minimal contamination is required.

• Airborne particle count:

  ≤10 particles per cubic meter (0.5 microns)

• Applications:

  MicroElectronics, precision optical devices

• Features:

  HEPA filters, controlled airflow

3. ISO3 Cleanroom

ISO3 cleanrooms permit up to 100 particles

per cubic meter of air. These are commonly used for applications such as biotechnology and pharmaceutical production, where sterile conditions are essential for product integrity.

• Airborne particle count:

  ≤100 particles per cubic meter (0.5 microns)

• Applications:

  Pharmaceuticals, biotechnology

• Features:

  HEPA filtration, airlocks, strict gowning procedures

4. ISO4 Cleanroom

ISO4 cleanrooms allow 1,000 particles

per cubic meter of air. They are suitable for industries requiring controlled environments but with slightly more tolerance for contamination compared to Classes 1-3.

• Airborne particle count:

  ≤1,000 particles per cubic meter (0.5 microns)

• Applications:

  Precision machinery, some pharmaceutical operations

• Features:

  High-efficiency air filtration, positive pressure airflow

5. ISO 5 Cleanroom (Class 100)

ISO5 allows 3,520 particles** per cubic meter of air (0.5 microns or larger), equivalent to **Class 100

in the U.S. Federal Standard 209E. It is often used in medical device manufacturing and laboratory settings where contamination control is critical but less stringent than in higher classes.

• Airborne particle count:

  ≤3,520 particles per cubic meter (0.5 microns)

• Applications:

  Medical device manufacturing, clean laboratories

• Features:

  Laminar airflow, high-efficiency particulate air (HEPA) filtration

6. ISO 6 Cleanroom (Class 1000)

ISO6 cleanrooms allow 35,200 particles

per cubic meter of air. These environments are typically used in less critical processes, such as some stages of drug production or electronics assembly.

• Airborne particle count:

• ≤35,200 particles per cubic meter (0.5 microns)

• Applications:

• Electronics assembly, drug manufacturing

• Features:

• Standard HEPA filters, moderate airflow control

7. ISO 7 Cleanroom (Class 10,000)

ISO 7 Cleanrooms can have up to 352,000 particles

per cubic meter of air. They are generally used in industries where contamination control is still important, but the environment is less sensitive than higher-level clean rooms.

• Airborne particle count:

• ≤352,000 particles per cubic meter (0.5 microns)

• Applications:

• Manufacturing of medical equipment, pharmaceuticals

• Features:

• Simple filtration, basic airflow systems

8. ISO 8 Cleanroom (Class 100,000)

ISO 8 cleanrooms allow up to 3.5 million particles

per cubic meter. They are used in less sensitive environments where particle control is still needed but the process doesn’t require the highest level of cleanliness.

• Airborne particle count:

• ≤3.5 million particles per cubic meter (0.5 microns)

• Applications:

• Food packaging, general industrial applications

• Features:

• Basic filtration, minimal air circulation systems

9. ISO9 Cleanroom

ISO9 modular cleanrooms have the least strict standards, allowing up to 35 million particles

per cubic meter. These environments are typically used in industries where air quality is controlled but not a primary concern.

• Airborne particle count:

• ≤35 million particles per cubic meter (0.5 microns)

• Applications:

• Low-sensitivity industrial environments

• Features:

• Basic particle filtration, limited air circulation

Relevant Standards and Guidelines

• ISO 14644-1:

  Defines CleanRoom Classifications based on particle count and provides testing and monitoring methods.

• ISO 14644-2:

  Specifies requirements for the monitoring and maintenance of cleanrooms.

• Federal Standard 209E:

  U.S. standard for cleanroom classification, now superseded by ISO 14644 but still referenced as Class 100, Class 1000, etc.

• GB 50073-2013:

  China’s national standard for cleanrooms, offering guidelines similar to ISO classifications.

By understanding clean room classifications, industries can design and maintain facilities that meet the specific cleanliness needs of their production processes.