FAQ

CLEANROOM CLASSIFICATIONS ACC. TO ISO 14644-1:2015 New ISO 14644-1:2015

Maximum concentration limits (particles M3 of air) for particles equal to and larger than the considered sizes shown below: (a)

ISO Classification Number(N)

0,1 μm

0,2 μm

0,3 μm

0,5 μm

1 μm

5 μm

ISO 1

b 10

d -2

ISO 2

100

24

10

d -4

ISO 3

1 000

237

102

35

d 8

ISO 4

10 000

2 370

1 020

352

83

ISO 5

100 000

23 700

10 200

3 520

832

d,e,f 29 

ISO 6

1 000 000

237 000

102 000

35 200

8 320

293

ISO 7

352 000

83 200

2 930

ISO 8

c

3 520 000

832 000

29 300

ISO 9

c

35 200 000

8 320 000

293 000

5.0µm should be zero according to ISO/DIS 14644-1.2 Table 1 notes;

d) Sampling and statistical limitations for particles in low concentrations make classification inappropriate
e) ... Greater than 1 micron particles make classification at this particle size inappropriate due to potential particle losses in sampling system
f) Specify particle size in association with ISO Class 5, the marcoparticle discriptor M may be adapted.