There isn't a single ISO class that automatically signifies sterility. Sterility is achieved through a combination of factors, including environmental controls (ISO class), sterilization processes, and rigorous quality control. However, ISO Class 5 is frequently cited as a requirement for environments where sterile compounding of medications takes place. This is because this level of cleanliness minimizes the risk of contamination during the preparation of sterile products.
ISO Class 5 and Sterility
ISO Class 5 air, with fewer than 100 particles 0.5 μm and larger per cubic meter, is commonly used in environments requiring sterile preparation. Examples include:
- Pharmaceutical compounding: Preparing intravenous (IV) bags, syringes, and single-dose vials.
- Cell culture: Maintaining a clean environment for sensitive cell growth.
- Microbiology research: Conducting experiments requiring contamination-free conditions.
Several sources mention ISO Class 5's use in sterile compounding areas, emphasizing its importance for maintaining a low-contamination environment necessary for sterility. While an ISO Class 5 environment is crucial, it's vital to remember that the ISO class alone doesn't guarantee sterility. Proper sterilization techniques and processes are also paramount.
Note: Other ISO classes, such as ISO Class 3, may also be used in sterile environments depending on the application and specific requirements. Products such as sterile gloves may be manufactured in ISO Class 3 or higher cleanrooms.
Other Relevant ISO Classes
It's important to understand that the ISO classification system focuses on particulate matter levels, not necessarily sterility. While a cleaner environment (lower ISO class) is less likely to be contaminated, sterility must be specifically verified through appropriate sterilization methods. Other ISO classes are commonly used in different applications requiring various levels of cleanliness:
- ISO Class 7: Often used as a buffer area surrounding an ISO Class 5 cleanroom.
- ISO Class 8: A less stringent cleanroom environment.
