IS0 14644-1:1999 Cleanroom Standard
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
IS0 14644-1:2015 Cleanroom Standard
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
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