Information on
Cleanroom classes
The concentration of airborne particles in cleanrooms must be kept below a certain level in order to protect the products produced in them. Particle measurements are carried out to determine cleanroom classes, usually using optical particle counters that record the size and number of particles. Cleanrooms are classified on the basis of the values determined.
Different standards exist for classification, which are used depending on the main contamination and industry. In semiconductor and aerospace technology, for example, the focus is on particles, in food technology on microorganisms and in pharmaceuticals on the bacterial count.
Common standards are ISO standard 14644-1 and GMP guideline Annex 1. The cleanroom classes are based on the maximum number of particles of a defined size of 0.1 micrometres to 5.0 micrometres per cubic metre of air.
Cleanroom classes according to ISO 14644-1
The cleanroom classes according to ISO 14644-1 focus on airborne particles. This standard is therefore primarily used in semiconductor production and aerospace technology. According to the EN ISO 14644-1 cleanroom classification, cleanrooms are divided into nine classes, with class 1 being the cleanest class.
| Class | ≥ 0.1 µm | ≥ 0.2 µm | ≥ 0.3 µm | ≥ 0.5 µm | ≥ 1.0 µm | ≥ 5.0 µm |
|---|---|---|---|---|---|---|
| ISO 1 | 10 | |||||
| ISO 2 | 100 | 24 | 10 | |||
| ISO 3 | 1,000 | 237 | 102 | 35 | ||
| ISO 4 | 10.000 | 2.370 | 1.020 | 352 | 83 | |
| ISO 5 | 100.000 | 23.700 | 10.200 | 3.520 | 832 | |
| ISO 6 | 1.000.000 | 237.000 | 102.000 | 35.200 | 8.320 | 293 |
| ISO 7 | 352.000 | 83.200 | 2.930 | |||
| ISO 8 | 3.520.000 | 832.000 | 29.300 | |||
| ISO 9 | 35.200.000 | 8.320.000 | 293.000 |
Cleanroom classes according to GMP guideline Annex 1
The GMP guidelines focus on microbiological and airborne contaminants; this standard is used, for example, in the production of pharmaceuticals. A distinction is made between cleanroom classes A, B, C and D, with class A having the strictest requirements.