ISO 14644-1 Cleanroom Standards

Mark Optics has an Outer Class 8 Clean Room that has tested at 13,000–18,000 particles size 0.5 µm, and our Inner Room is a Class 6 and under the hood is a Class 5.

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) cancelled 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 3500 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