In order to avoid the cleanliness of the turnkey modular clean room by the pollution near the non-clean room, the appropriate static pressure difference shall be maintained between the clean room and the general room, and the static pressure difference shall not be less than 5Pa.The difference of pressure from the outdoor is not less than 10Pa.
| Class | Maximum Particles/m³ | FED STD 209E equivalent | |||||
| ≥0.1µｍ | ≥0.2µｍ | ≥0.3µｍ | ≥0.5µｍ | ≥1µｍ | ≥5µｍ | ||
| ISO 1 | 10 | 2 | |||||
| ISO 2 | 100 | 24 | 10 | 4 | |||
| ISO 3 | 1,000 | 237 | 102 | 35 | 8 | Class 1 | |
| ISO 4 | 10,000 | 2,370 | 1,020 | 352 | 83 | 3 | Class 10 |
| ISO 5 | 100,000 | 23,700 | 10,200 | 3,520 | 832 | 29 | Class 100 |
| ISO 6 | 1,000,000 | 237,000 | 102,000 | 35,200 | 8,320 | 293 | Class 1,000 |
| ISO 7 | 352,000 | 83,200 | 2,930 | Class 10,000 | |||
| ISO 8 | 3,520,000 | 832,000 | 29,300 | Class 100,000 | |||
| ISO 9 | 35,200,000 | 8,320,000 | 293,000 | Room Air | |||
