Clean Room Classifications 

(ISO 5, ISO 6, ISO 7, ISO 8)

Clean rooms are controlled environments essential for manufacturing processes that require extremely low levels of environmental pollutants. Understanding proper Clean Room Classifications is fundamental to ensuring product quality and regulatory compliance across multiple industries.

The International Organization for Standardization (ISO) developed the ISO 14644-1 standard to provide a global framework for Clean Room Classifications. This guide focuses specifically on ISO 5, ISO 6, ISO 7, and ISO 8 classifications, which represent the most commonly implemented cleanroom standards in industrial applications. Proper implementation of these Clean Room Classifications ensures consistent product quality and regulatory compliance.

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modular cleanroom

ISO CLEANROOMS CLASSIFICATION

Various standards have been developed to classify cleanrooms based on their cleanliness levels. The most widely recognized standards include ISO 14644-1 and the now-withdrawn US FED STD 209E. Understanding these Clean Room Classifications is essential for proper facility design and operation.

The ISO 14644-1 standard has become the global benchmark for Clean Room Classifications, replacing most national standards. It classifies cleanrooms from ISO 1 (cleanest) to ISO 9 (least clean) based on the maximum allowable concentrations of airborne particles. Deiiang™ specialists help clients navigate these complex Clean Room Classifications requirements for international compliance.

ISO 5 CLEANROOM

Briefly defines ISO 5 cleanrooms as highly controlled environments with stringent particle limits, essential for sensitive processes requiring ultra-clean conditions.

Air Changes per Hour: High ACH, typically 240-600

Airflow: Usually unidirectional (laminar) airflow

Application Industries:

  • Semiconductor Manufacturing
  • Pharmaceutical Production (Sterile)
  • Medical Device Manufacturing

Deiiang™ designs incorporate energy-efficient fan filter units (FFUs) that maintain consistent airflow while reducing operational costs by up to 30% compared to conventional systems.

ISO 6 CLEANROOM

ISO 6 cleanrooms offer a controlled environment with fewer particles than ISO 5, suitable for applications requiring high cleanliness but less stringent than ISO 5.

Air Changes per Hour: ACH typically ranges from 90-180

Airflow Pattern: Non-unidirectional airflow.

Application Industries :

  • Electronics Assembly
  • Pharmaceutical Manufacturing (Non-Sterile)
  • Optics Manufacturing
  • Data Storage

Deiiang™ engineered solutions optimize airflow patterns to minimize turbulence while ensuring complete room air exchange every 20-40 seconds, maintaining particle counts below 35,200 particles/m³ at ≥0.5µm.

ISO 7 CLEANROOM

ISO 7 cleanrooms maintain a defined level of cleanliness, commonly used as a buffer zone or support area for more critical cleanrooms.

Air Changes per Hour: Air changes typically range from 30-60, balancing cleanliness with operational costs.

Airflow Pattern: Non-unidirectional airflow.

Application Industries:

  • Pharmaceutical Compounding
  • Medical Device Packaging
  • Food Processing
  • Research Labs

Deiiang™ energy recovery ventilation systems for ISO 7 applications can reduce HVAC operating costs by up to 40% while maintaining compliance with ISO 14644-1 particle limits of 352,000 particles/m³ at ≥0.5µm.

ISO 8 CLEANROOM

ISO 8 cleanrooms provide a controlled environment with the lowest level of cleanliness among ISO cleanroom classifications, often used as entryways or support areas.

Air Changes per Hour : ACH typically ranges from 5-20, providing basic contamination control.

Airflow Pattern : Usually turbulent airflow with basic filtration systems.

Application Industries :

  • General Packaging
  • Warehousing
  • Material Storage
  • Preliminary Assembly

Deiiang™ ISO 8 designs focus on operational efficiency with modular components that allow for future upgrades to higher classifications, protecting your investment while meeting current Clean Room Classifications requirements.

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ISO 14644-1 STANDARD

ISO 14644-1 classifies cleanrooms based on the maximum allowable concentrations of airborne particles per cubic meter of air. The standard uses the following formula to determine particle concentration limits: Cn = 10N × (0.1/D)2.08, where N is the ISO class number and D is the particle size in micrometers.
ISO Class ≥0.1 µm ≥0.2 µm ≥0.3 ≥0.5 ≥1 µm ≥5
ISO 1 10 2 1 – – –
ISO 2 100 24 10 4 – –
ISO 3 1,000 237 102 35 8 –
ISO 4 10,000 2,370 1,020 352 83 –
ISO 5 100,000 23,700 10,200 3,520 832 29
ISO 6 1,000,000 237,000 102,000 35,200 8,320 293
ISO 7 – – – 352,000 83,200 2,930
ISO 8 – – – 3,520,000 832,000 29,300
ISO 9 – – – 35,200,000 8,320,000 293,000
Understanding these Clean Room Classifications is critical for proper facility design. For example, an ISO 5 CLEANROOM allows a maximum of 3,520 particles ≥0.5µm per cubic meter, while an ISO 8 CLEANROOM permits 3,520,000 particles of the same size. This 1,000-fold difference demonstrates the importance of accurate Clean Room Classifications selection.

Air Changes Per Hour

Air Changes per Hour (ACH) is a crucial parameter in cleanroom design, representing the number of times the air volume in a room is replaced per hour. Higher ACH values generally indicate greater cleanliness, as contaminated air is replaced more frequently. The appropriate ACH depends on the ISO classification and the sensitivity of the processes within the cleanroom.
ISO Class Air Changes per Hour (ACH) Corresponding FS 209E Class
ISO 1 Very High (500+)  N/A
ISO 2 Very High (400-500)  N/A
ISO 3 High (300-400) Class 1
ISO 4 High (200-300) Class 10
ISO 5 240-600 Class 100
ISO 6 90-180 Class 1,000
ISO 7 30-60 Class 10,000
ISO 8 5-20 Class 100,000
ISO 9 <5 N/A

Note: The Air Changes per Hour values are typical ranges and can vary based on specific application and cleanroom design. FS 209E is an older standard, but included for reference.

FAQ

What is the difference between ISO 14644 and FS209E classifications?

ISO 14644-1 is the current international standard, while FS209E was the previous US standard. ISO 5 is approximately equivalent to Class 100, ISO 6 to Class 1,000, ISO 7 to Class 10,000, and ISO 8 to Class 100,000 in the FS209E system.

How often should cleanroom certification testing be performed?

ISO 14644-2 recommends maximum time intervals for testing: 6 months for particle counts in ISO 5-8 cleanrooms, 12 months for air pressure difference, and 24 months for airflow velocity and volume. More frequent testing may be required based on risk assessment.

Can a cleanroom be upgraded to a higher classification?

Yes, but upgrades typically require significant modifications including increased air changes, improved filtration, enhanced sealing, and potentially different airflow patterns. Deiiang™ can assess existing facilities and provide upgrade solutions.