A Class D cleanroom is a controlled environment used in manufacturing processes, particularly those less critical than aseptic processing, and is equivalent to an ISO Class 8 cleanroom.
Here's a more detailed breakdown:
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Purpose: Class D cleanrooms are designed for stages in production where maintaining a high level of cleanliness is important but not as stringent as in higher-grade cleanrooms. This might include preparation stages before final sterilization or filling.
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ISO Equivalence: They are the equivalent of ISO Class 8 cleanrooms both when "at rest" (no activity) and during operation. This means they maintain the same cleanliness standards regardless of whether activities are taking place inside.
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Particle Count Limits: The defining characteristic is the maximum allowable concentration of airborne particles. For a Class D cleanroom, this is:
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3,520,000 particles (0.5 µm or larger) per cubic meter
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200,000 particles (0.5 µm or larger) per cubic foot
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Applications: Common uses include:
- Manufacturing of non-sterile products
- Preparation areas for sterile product manufacturing
- Packaging areas for certain products
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Air Changes: While not explicitly stated in the definition of a Class D cleanroom, achieving these particle counts typically requires a certain number of air changes per hour (ACH). The specific ACH will depend on the activities being performed and the design of the cleanroom.
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Personnel and Procedures: Strict adherence to cleanroom protocols, including gowning procedures and cleaning schedules, is crucial for maintaining the Class D standard.
In summary, a Class D cleanroom provides a controlled environment for manufacturing processes where cleanliness is important but not requiring the same level of stringency as higher classes. It is equivalent to an ISO Class 8 cleanroom and has defined limits on the number of airborne particles allowed.
