Risk
class
4
3
2
Particulate
cleanliness class
ISO 5
ISO 7
ISO 8
Particles
elimination kinetics
CP 5
CP 10
CP 20
Microbiological
cleanliness class
M1
M10
M100
Differential pressure
negative/positive
15 Pa ± 5 Pa
–
–
15 Pa ± 5 Pa
15 Pa ± 5 Pa
Temperature
range
19° to 26° C
–
–
19° to 26° C
19° to 26° C
Air flow speed
in the area
to be protected
Unidirectional flow
–
–
Unidirectional flow
Or no-unidirectional flow
No-unidirectional flow
Other specifications,
minimum values
Airflow zone speed
from 0.25 m/s to 0.35 m/s
Fresh air rate of minimum or equal to 6 volumes per hour
Change rate of minimum or equal to 15 volumes per hour
Change rate of minimum or equal to 15 volumes per hour