Grade D in ISO refers to a specific classification of cleanrooms, primarily used in manufacturing processes. Specifically, a Grade D cleanroom is designated for less critical stages in the manufacturing process.
Key Characteristics of ISO Grade D Cleanrooms
Here's a breakdown of what defines a Grade D cleanroom:
- Classification Equivalent: A Grade D cleanroom is equivalent to an ISO Class 8 cleanroom, both in its "at rest" and "in operation" states. This means it has similar requirements for air quality and particle control.
- Particle Count: The maximum allowed concentration of airborne particles in a Grade D cleanroom is:
- 3,520,000 particles ≥ 0.5 µm per cubic meter
Practical Applications
- Less Critical Processes: Grade D cleanrooms are typically used for stages of manufacturing that have lower sensitivity to contamination.
- Specific Industry Use: These cleanrooms can be found in various sectors, like certain pharmaceutical production, food production, and electronics assembly.
- Example: A Grade D cleanroom might be used for the initial stages of packaging products or for less sensitive steps in a manufacturing line, where the risk of product contamination is lower.
Comparing with Other Grades
It is important to note that other grades (A, B, and C) have more stringent requirements. Grade A is the highest standard used for very critical operations such as sterile filling. Grade D is a lower grade compared to A, B, and C which require higher stringency.
| Grade | Description | Maximum Particle Count (≥ 0.5 µm per cubic meter) |
|---|---|---|
| Grade A | Critical operations with high risk of contamination | Very low |
| Grade B | Supporting operations for critical operations | Low |
| Grade C | Less critical operations | Moderate |
| Grade D | Less critical stages in manufacturing process | 3,520,000 |
In summary, Grade D in ISO signifies a particular level of cleanliness, associated with an ISO Class 8 environment, suitable for less critical stages in manufacturing processes.
