A cleanroom rating is a classification system that defines the level of cleanliness within a cleanroom. It's usually expressed in ISO classes, which range from ISO 1 (the cleanest) to ISO 9 (the least clean). The ISO class is determined by the maximum number of particles allowed per cubic meter at a specified particle size.
For instance, an ISO Class 5 cleanroom must maintain a particle count of fewer than 3,520 particles per cubic meter of air at 0.5 micrometers or larger. These stringent requirements ensure that the environment meets the specific needs of the industry it serves.
