Qualification and categorization of the air of clean premises in accordance with ISO
Categorization of clean premises and micro-environments
The International Organization for Standardization (ISO) develops standards of particle concentration in clean premises. ISO 14644-1 defines standard classes of air purity for clean rooms and areas, based upon defined concentrations of air particles. The actual acceptable limits of particles according to the ISO class are demonstrated in the TABLE
| CLASS | NUMBER OF PARTICLES PER CUBIC METER BY MICROMETER SIZE | |||||
|---|---|---|---|---|---|---|
| 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 | 29 |
| 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 |
Evaluation and certification of a clean room
Certification of a clean room takes place after construction or significant physical modifications. Certification guarantees that installation complies with the requirements on acceptable maximum particles concentration in the air. Certification of a clean room can take place on any of the three different stages: As-built, at rest or in operation.
For additional information refer to ISO 14644 documentation.