ISO 14644-1 Cleanroom Standards

						maximum particle/m³
Class	0.1 µm	0.2 µm	0.3 µm	0.5 µm	1.0 µm	5.0 µm
ISO 1	10	2
ISO 2	100	24	10	4
ISO 3	1,000	237	102	35	8
ISO 4	10,000	2,370	1,020	352	83
ISO 5	100,000	23,700	10,200	3,520	832	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				3,520,000	832,000	29,300
ISO 9				35,200,000	8,320,000	293,000

 

On November 29, 2001, the U.S. General Services Administration (GSA) canceled Federal Standard 209E (FED-STD-209E), Airborne Particulate Cleanliness Classes in Cleanrooms and Clean Zones. The current standard is ISO 14644-1 and is meant to completely replace FED-STD-209E. Each of these standards represents the maximum allowable number of particles in a unit of air (m³/ft³). The particle counts are always listed as cumulative.

US FED STD 209E Cleanroom Standards

Class	0.1 µm	0.2 µm	0.3 µm	0.5 µm	1 µm	5 µm
1	35	7	3	1
10	350	75	30	10	1
100	3,500	750	300	100	10	1
1,000				1,000	100	10
10,000				10,000	1,000	100
100,000				100,000	10,000	1,000

Cleanroom Class Comparison

ISO 14644-1	FED STD 209E
ISO 3	1
ISO 4	10
ISO 5	100
ISO 6	1,000
ISO 7	10,000
ISO 8	100,000