The ISO 14644 family of standards serves as a comprehensive guide for establishing and maintaining cleanroom environments, especially in the manufacturing of sterile devices. ISO 14644, in particular, is an internationally recognized standard that provides guidelines for the design, construction, validation, and operation of cleanrooms.
Throughout our discussions, we have covered various topics pertaining to sterile devices, including ISO 11135 and the gamma sterilization process, packaging considerations, and related information.
The ISO 14644 series consists of several individual standards, each addressing specific aspects related to cleanrooms, such as their characteristics, validation approaches, and classifications. These standards offer valuable insights and requirements to ensure cleanrooms meet the necessary cleanliness levels and performance criteria.
To begin, let us establish a clear understanding of what constitutes a “cleanroom.” A cleanroom is an enclosed environment equipped with specialized equipment that effectively controls the quantity of particulate matter in the air. This is achieved through the use of air pressure differentials and filtration systems, maintaining a controlled and clean atmosphere within the room.
By adhering to the ISO 14644 standards, manufacturers can ensure the quality and sterility of their products, minimizing the risk of contamination and maintaining a controlled environment conducive to the production of sterile devices. These standards play a crucial role in promoting patient safety and the overall reliability of medical devices manufactured in cleanroom environments.
Classification of Cleanrooms according to ISO 14644
Cleanrooms are categorized based on the level of air cleanliness maintained within the controlled environment. The classification of a cleanroom refers to its compliance with specific cleanliness standards, determined by the quantity and size of particles present per cubic meter of air. The primary authority governing cleanroom classifications in the United States and Canada is the ISO classification system outlined in ISO 14644-1.
ISO 14644-1 establishes a set of cleanroom classes, each representing a different level of cleanliness. The classes range from ISO 1, which is the highest level of cleanliness, to ISO 9, which is the lowest. It’s important to note that even the ISO 9 class, considered the “dirtiest,” still maintains a cleaner environment compared to a regular room.
The following table presents the complete ISO classification system along with the corresponding characteristics of particles for each ISO class:
| Class | maximum particles/m3 | |||||
| >=0.1 µm | >=0.2 µm | >=0.3 µm | >=0.5 µm | >=1 µm | >=5 µm | |
| ISO 1 | 10 | 2 | ||||
| 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 |
Each ISO class signifies a progressively higher threshold for cleanliness, with ISO 1 being the most stringent and ISO 9 representing a controlled environment suitable for less critical applications.
Adhering to the appropriate cleanroom classification ensures that manufacturers can maintain the necessary levels of cleanliness and minimize the presence of particles that could potentially compromise the sterility and quality of sensitive products produced within the cleanroom environment.
Controls of Cleanroom Environment
The ISO 14644 standard provides guidelines for testing cleanrooms under three different conditions, namely “As built,” “At rest,” and “In operation.” Each condition involves specific measurements to evaluate the cleanliness and performance of the cleanroom.
In the “As built” scenario, measurements are conducted once the construction of the cleanroom is complete, but before machinery and personnel are introduced. This allows for a baseline assessment of the cleanroom’s initial state.
The “At rest” condition involves measurements taken while the machinery is operational but without personnel present. This assessment helps evaluate the cleanroom’s performance in terms of particle control and cleanliness when the equipment is running.
The “In operation” scenario requires measurements to be taken with both machinery and personnel present and actively engaged in their regular activities. This condition provides insights into the cleanroom’s performance during real-life operation, taking into account the presence of people and the associated particle generation.
To ensure accurate measurement of parameters, ISO 14644-1 outlines several essential points:
- The number of measurement points should be determined based on the square root of the cleanroom’s surface area in square meters. This ensures an adequate representation of the cleanroom’s overall cleanliness.
- The volume of air sampled at each point must be sufficient to contain at least 20 particles of the largest size specified. In any case, the minimum volume of air should not be less than two liters, and the sampling time should exceed one minute. This ensures reliable particle counting and accurate assessment of cleanliness.
- At least one air sample per measurement point should be taken, with the recommendation to take three samples if there is only one measuring point. Multiple samples help account for potential spatial variations within the cleanroom.
Following these guidelines for measurement and testing helps ensure consistent and reliable assessment of cleanroom cleanliness and adherence to the established ISO standards. It enables manufacturers and operators to identify any areas requiring improvement, maintain optimal cleanliness levels, and ultimately produce high-quality products within the controlled cleanroom environment.
ISO 14644 Family of standards
Here below we report the full list of ISO 14644 family standards related to cleanroom:
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