Cleanrooms are classified by the level of airborne particle control. ISO 14644-1 classification is based on airborne particle concentration. The required class depends on the process and contamination control requirements.

  1. ISO 5 cleanrooms

This is a high-cleanliness class commonly used in pharmaceuticals, medical devices, microelectronics and aseptic areas. Rooms generally use HEPA filtration and tightly controlled airflow.

  1. ISO 6 cleanrooms

Particle control is stringent but less demanding than ISO 5. Common applications include electronic components, pharmaceuticals and areas requiring a clean environment..

  1. ISO 7 cleanrooms

A common class used in pharmaceutical, food, cosmetics and electronics factories and production rooms. HVAC, air filtration and pressure differentials are controlled to maintain stable conditions.

  1. ISO 8 cleanrooms

This class has less stringent particle limits than ISO 7 and is commonly used in packaging, clean storage, food and cosmetics production, and support areas..

  1. Pharmaceutical Grades D, C, B and A

In pharmaceuticals, cleanrooms may also be assessed using Grades A, B, C and D. In this system:

  • Grade A: Areas with the most stringent contamination-control requirements.
  • Grade B: The background environment supporting Grade A.
  • Grade C: Production areas requiring an intermediate level of control.
  • Grade D: Areas with less stringent cleanliness requirements.

Conclusion

The choice of cleanroom class depends on intended use, manufacturing processes and contamination-control requirements. HVAC, HEPA filters, pressure differentials, temperature and humidity must be designed for the required class.