| Class |
maximum particles/m³ |
FED STD 209E
equivalent |
| ≥0.1 µm |
≥0.2 µm |
≥0.3 µm |
≥0.5 µm |
≥1 µm |
≥5 µm |
| 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 |
|
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 1000 |
| 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 |
|
| |
maximum particles/m³ |
| Class |
≥0.5 µm |
≥1 µm |
≥5 µm |
≥10 µm |
≥25 µm |
| Class 1 |
3,000 |
|
0 |
0 |
0 |
| Class 2 |
300,000 |
|
2,000 |
30 |
|
| Class 3 |
|
1,000,000 |
20,000 |
4,000 |
300 |
| Class 4 |
|
|
200,000 |
40,000 |
4,000 |
|
