What is the Colony Forming Unit action level for ISO Class 5?

The Colony Forming Unit (CFU) action level for ISO Class 5 is indeed 1 CFU (not to exceed 3 CFU). This standard is primarily established to ensure that the environment in which sterile preparations are compounded remains as safe and controlled as possible. ISO Class 5 environments are critical for minimizing the risk of microbial contamination during the compounding of sterile preparations.

A level of 1 CFU indicates that no more than one colony-forming unit is permitted within a specified volume of air or surface area. If the CFU count exceeds this level (greater than 3), it triggers corrective action to address potential contamination risks. In sterile compounding settings, strict adherence to these standards is crucial, as even minimal contamination can lead to serious patient safety issues.

Other options present CFU levels that either exceed the acceptable limits for ISO Class 5 or do not accurately reflect the standards established for such compounding environments. Therefore, understanding these limits plays a critical role in maintaining compliance with sterile compounding guidelines.