Clean Rooms can cost upwards of $1Million dollars.

March 01, 2021

One of the most important factors in Manufacturing a medical product like Dent-x Surgical masks is the Clean Room.

Cleanroom Classifications

Cleanrooms are classified by how clean the air is. In Federal Standard 209 (A to D) of the USA, the number of particles equal to and greater than 0.5µm is measured in one cubic foot of air, and this count is used to classify the cleanroom. This metric nomenclature is also accepted in the most recent 209E version of the Standard. Federal Standard 209E is used domestically. The newer standard is TC 209 from the International Standards Organization. Both standards classify a cleanroom by the number of particles found in the laboratory's air. The cleanroom classification standards FS 209E and ISO 14644-1 require specific particle count measurements and calculations to classify the cleanliness level of a cleanroom or clean area. In the UK, British Standard 5295 is used to classify cleanrooms. This standard is about to be superseded by BS EN ISO 14644-1.

Cleanrooms are classified according to the number and size of particles permitted per volume of air. Large numbers like "class 100" or "class 1000" refer to FED_STD-209E, and denote the number of particles of size 0.5 µm or larger permitted per cubic foot of air. The standard also allows interpolation, so it is possible to describe e.g. "class 2000."

Small numbers refer to ISO 14644-1 standards, which specify the decimal logarithm of the number of particles 0.1 µm or larger permitted per cubic metre of air. So, for example, an ISO class 5 cleanroom has at most 105 = 100,000 particles per m³.

Both FS 209E and ISO 14644-1 assume log-log relationships between particle size and particle concentration. For that reason, there is no such thing as zero particle concentration. Ordinary room air is approximately class 1,000,000 or ISO 9.

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ISO 14644-1 Cleanroom 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

BS 5295 Cleanroom Standards

  maximum particles/m3
Class >=0.5 µm >=1 µm >=5 µm >=10 µm >=25 µm
Class 1 3,000   0 0 0
Class 2 300,000   2,000 30  
Class 3   1,000,000 20,000 4,000 300
Class 4     20,000 40,000 4,000

Clean Air Technology, Inc. 41105 Capital Drive, Canton, MI 48187 USA