2022-02-22

Clean rooms are classified according to the cleanliness of the air. Specific particle count measurements and calculations are required by the clean room classification standard ISO 14644-1, which specifies the decimal logarithm of the number of particles of 0.1 µm or more allowed per cubic meter of air to classify the cleanliness level of the clean room or clean area.
ISO 14644-1 Clean room Standards
Class maximum particles/m3 FED STD 209E
equivalent
>=0.1 µm >=0.2 µm >=0.3 µm >=0.5 µm >=1 µm >=5 µm
ISO 1 10 2          
ISO 2 100 24 10 4      
ISO 3 1,000 237 102 35 8   Class 1
ISO 4 10,000 2,370 1,020 352 83   Class 10
ISO 5 100,000 23,700 10,200 3,520 832 29 Class 100
ISO 6 1,000,000 237,000 102,000 35,200 8,320 293 Class 1,000
ISO 7       352,000 83,200 2,930 Class 10,000
ISO 8       3,520,000 832,000 29,300 Class 100,000
ISO 9       35,200,000 8,320,000 293,000 Room Air
Clean room is a controlled environment with low pollutant level. It is usually used in electronic manufacturing, food production, medical product research and scientific laboratory.