South Carolina Multistate Pharmacy Jurisprudence Examination (MPJE) Practice Exam

Which classification allows fewer than 352,000 particles per 0.5 mm?

1. ISO 5

2. ISO 7

3. ISO 8

4. ISO 10

The correct answer is: ISO 7

The classification that allows fewer than 352,000 particles per 0.5 mm is ISO 7. This classification is part of the ISO 14644-1 standard, which defines the cleanliness levels of airborne particulate contamination in cleanrooms and controlled environments. Specifically, ISO 7 permits a maximum of 352,000 particles per cubic meter for particles that are 0.5 micrometers or larger. In broader context, higher ISO classifications, such as ISO 5, allow fewer particles overall (with only 3,520 particles allowed per 0.5 mm), making it suitable for more stringent sterile environments like certain areas in pharmacies where aseptic compounding occurs. Conversely, ISO 8 has a higher tolerance for particle count—up to 3.2 million particles per cubic meter—making it less stringent. ISO 10 further expands the allowable particle count beyond that of ISO 7. Therefore, knowing the standards and specific particle limits of each classification helps in understanding the requirements for different controlled environments, particularly in the context of pharmaceuticals where sterility is crucial.