What does a higher ISO class number typically indicate in terms of cleanliness?

A higher ISO class number indicates that more particles are allowed in the environment. The ISO classification system for cleanrooms specifies the maximum allowable particle concentration for a given class. As the ISO class number increases, this means that the standards for particulates become less strict, allowing for a greater number of particles in the air per cubic meter.

For example, an ISO 5 cleanroom has stricter cleanliness standards compared to an ISO 9 cleanroom. This is crucial in environments that require controlled levels of contamination, such as pharmaceutical manufacturing or healthcare settings, where maintaining lower particle counts is essential for product integrity and patient safety.

The context of other options involves aspects that do not directly correlate with ISO class numbers. Stricter cleanliness standards are associated with lower ISO class numbers, while humidity levels and air pressure are important factors in cleanroom management but aren't defined by ISO class numbers.