Cleanliness
The cleanroom classification standards FS 209E and ISO 14644-1 require specific particle count measurements and calculations to classify the cleanliness level of a cleanroom or clean area.
ISO 14644-1
| Maximum concentration limits (particles/m3 ) |
| Classification
Number (N) |
0.1μm |
0.2μm |
0.3μm |
0.5μm |
1.0μm |
5.0μm |
| ISO Class 1 |
10 |
2 |
– |
– |
– |
– |
| ISO Class 2 |
100
| 24 |
10 |
4 |
– |
– |
| ISO Class 3 |
1,000
| 237 |
102 |
35.2 |
8 |
– |
| ISO Class 4 |
10,000
| 2,370 |
1,020 |
352 |
83 |
– |
| ISO Class 5 |
100,000 |
23,700 |
10,200 |
3,520 |
832 |
29 |
| ISO Class 6 |
1,000,000 |
237,000 |
102,000 |
35,200 |
83,200 |
293 |
| ISO Class 7 |
– |
– |
– |
352,000 |
832,000 |
2,930 |
| ISO Class 8 |
– |
– |
– |
35,200,000 |
8,320,000 |
29,300 |
| ISO Class 9 |
– |
– |
– |
– |
– |
293,000 |
Federal Standard 209E Airborne Particulate Cleanliness Classes
| ICR Cleanliness |
Diameter for Airborne Particle
|
| 0.1μm |
0.2μm |
0.3μm |
0.5μm |
0.5μm |
| Volume Units |
Volume Units |
Volume Units |
Volume Units |
Volume Units |
| SI |
Class |
(m3) |
(ft3) |
(m3) |
(ft3) |
(m3) |
(ft3) |
(m3) |
(ft3) |
(m3) |
(ft3) |
| M1 |
|
350 |
9.91 |
75.7 |
2.14 |
30.9 |
0.875 |
10.0 |
0.283 |
– |
– |
| M1.5 |
1 |
1240 |
35.0 |
265 |
7.50 |
106 |
3.00 |
35.3 |
1.00 |
– |
– |
| M2 |
|
3,500 |
99.1 |
757 |
21.4 |
309 |
8.75 |
100 |
2.83 |
– |
– |
| M2.5 |
10 |
12,400 |
350 |
2,650 |
75.0 |
1,060 |
30.0 |
353 |
10.0 |
– |
– |
| M3 |
|
35,000 |
991 |
7,570 |
214 |
3,090 |
87.5 |
1,000 |
28.3 |
– |
– |
| M3.5 |
100 |
– |
– |
26,500 |
750 |
10.600 |
300 |
3,530 |
100 |
– |
– |
| M4 |
|
– |
– |
75,700 |
2,140 |
30,900 |
875 |
10,000 |
283 |
– |
– |
| M4.5 |
1000 |
– |
– |
– |
– |
– |
– |
35,300 |
1,000 |
247 |
7.00 |
| M5 |
|
– |
– |
– |
– |
– |
– |
100,000 |
2,830 |
618 |
17.5 |
| M5.5 |
10,000 |
– |
– |
– |
– |
– |
– |
353,000 |
10,000 |
2,470 |
70.0 |
| M6 |
|
– |
– |
– |
– |
– |
– |
1,000,000 |
28,300 |
6,180 |
175 |
| M6.5 |
100,000 |
– |
– |
– |
– |
– |
– |
3,530,000 |
100,00 |
24,700 |
700 |
| M7 |
|
– |
– |
– |
– |
– |
– |
10,000,000 |
283,000 |
61,800 |
1,750 |
JIS B 9920
| Class |
Maximum concentration limits (particles/m3 ) |
| 0.1μm |
0.2μm |
0.3μm |
0.5μm |
1μm |
05μm |
| Class1 |
10 |
2 |
— |
— |
— |
— |
| Class2 |
100
| 24 |
10 |
4 |
— |
— |
| Class3 |
100
| 237 |
102 |
35 |
8 |
— |
| Class4 |
10,000
| 2,370 |
1,020 |
352 |
83 |
— |
| Class5 |
100,000 |
23,700 |
10,200 |
3,520 |
832 |
29 |
| Class6 |
— |
237,000 |
102,000 |
35,200 |
8,320 |
293 |
| Class7 |
— |
— |
— |
352,000 |
83,200 |
2,930 |
| Class8 |
— |
— |
— |
3,520,000 |
832,000 |
29,300 |
| Class9 |
— |
— |
— |
35,200,000 |
8,320,000 |
293,000 |
Worldwide Standard comparison
| Worldwide Standard |
Class |
| ISO 14644-1 |
ISO 3 |
ISO 4 |
ISO 5 |
ISO 6 |
ISO 7 |
ISO 8 |
| FS 209E |
Class 1 |
Class 10 |
Class 100 |
Class 1000 |
Class 10000 |
Class 100000 |
| FS 209E(SI) |
M1.5 |
M2.5 |
M3.5 |
M4.5 |
M5.5 |
M6.5 |
| JIS B 9920 |
Class 3 |
Class 4 |
Class 5 |
Class 6 |
Class 7 |
Class 8 |
| Britain BS 5295 |
C |
D |
E/F |
G/H |
J |
K |
| Germany VD I.2083 |
1C |
2 |
3 |
4 |
5 |
6 |
| Australia AS 1386 |
0.035
|
0.35
|
3.5 |
35 |
350 |
3500 |
| France AFNOR X44101 |
— |
— |
4,000 |
— |
4,000 |
4,000,000 |
| Grade |
– |
A/B |
– |
C |