Cleanroom Standards

ISO Classification - m3

Class

Maximum Concentration Limits (Particles/m³ of air) for Particles Equal to and Larger Than the Considered Sizes Shown Below

 

0.1µm

0.2µm

0.3µm

0.5µm

1µm

5µm

ISO Class 1

4

2

-

-

-

-

ISO Class 2

100

24

10

4

-

-

ISO Class 3

1 000

237

102

35

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

8 320

293

ISO Class 7

-

-

-

352 000

83 200

2 930

ISO Class 8

-

-

-

3 520 000

832 000

29 300

ISO Class 9

-

-

-

35 200 000

8 320 000

293 000


GMP Classification – m3

Grade

Maximum Permitted Number of Particles/m³ - Equal to or Greater Than

 

At Rest

In Operation

 

0.5µm

5µm

0.5µm

5µm

A

3 500

0

3 500

0

B

3 500

0

350 000

2 000

C

350 000

2 000

3 500 000

20 000

D

3 500 000

20 000

Not defined

Not defined


American Federal Standard 209E – ft3

Class

Class Limits with Maximum Number of Particles/ft³

Imperial

0.1µm

0.2µm

0.3µm

0.5µm

5µm

1

35.0

7.50

3.00

1.00

-

10

350

75.0

30.0

10.0

-

100

-

750

300

100

-

1 000

-

-

-

1 000

7.00

10 000

-

-

-

10 000

70.0

100 000

-

-

-

100 000

700