Cleanroom Classifications
What is a cleanroom?
The most accurate way of answering this question is by quoting the ISO standard definition of a cleanroom. This is the standard which all cleanrooms must conform to and the following explanation gives the defining parameters of a cleanroom -
A cleanroom is a "room within which the number concentration of airborne particles is controlled and classified, and which is designed, constructed and operated in a manner to control the introduction, generation and retention of particles inside the room".
Ref: BS EN ISO 14644-1:2015 Cleanrooms and associated controlled environments - Part 1: Classification of air cleanliness by particle concentration
Cleanroom Classification Table
| Cleanroom Standard | Cleanroom Classification Guidelines | |||||
|---|---|---|---|---|---|---|
| ISO 14644-1 | Class 3 | Class 4 | Class 5 | Class 6 | Class 7 | Class 8 |
| Federal Standard 209E | 1 | 10 | 100 | 1,000 | 10,000 | 100,000 |
| EU GMP | - | - | A/B | - | C | D |
| Air changes / hour | 360-540 | 300-540 | 240-480 | 150-240 | 60-90 | 5-48 |
ISO Classes of air cleanliness by particle concentration
For cleanrooms and clean zones shown in ISO 14644-1:2015
| ISO Classification Number | Maximum allowable concentrations (particles/m3) for particles equal to and greater than the considered sizes, shown below | |||||
|---|---|---|---|---|---|---|
| ≥0.1µm | ≥0.2µm | ≥0.3µm | ≥0.5µm | ≥1µm | ≥5.0µm | |
| ISO Class 1 | 10b | d | d | d | d | e |
| ISO Class 2 | 100 | 24b | 10b | d | d | e |
| ISO Class 3 | 1,000 | 237 | 102 | 35b | d | e |
| ISO Class 4 | 10,000 | 2,370 | 1,020 | 352 | 83b | e |
| ISO Class 5 | 100,000 | 23,700 | 10,200 | 3,520 | 832 | d,e,f |
| ISO Class 6 | 1,000,000 | 237,000 | 102,000 | 35,200 | 8,320 | 293 |
| ISO Class 7 | c | c | c | 352,000 | 83,200 | 2,930 |
| ISO Class 8 | c | c | c | 3,520,000 | 832,000 | 29,300 |
| ISO Class 9g | c | c | c | 35,200,000 | 8,320,000 | 293,000 |
Cleanroom Limits for Airborne Particulate Contamination
Clean room and clean air device classification, in relation to GMP (2008).
| Cleanroom Standard | Maximum permitted number of particles /m³ | ||||
|---|---|---|---|---|---|
| EU GMP Grade | ISO EN 14644-1 | At rest ≥0.5µm | At rest ≥5.0µm | In operation ≥0.5µm | In operation ≥5.0µm |
| A | 5 | 3,520 | 20 | 3,520 | 20 |
| B | 5 | 3,520 | 29 | 352,000 | 2,900 |
| C | 7 | 352,000 | 2,900 | 3,520,000 | 29,000 |
| D | 8 | 3,520,000 | 29,000 | Not defined | Not defined |
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