Classification of Cleanrooms
FS 209E
Undoubtedly the best know cleanroom classification levels are the Federal Standard 209E, it was issued in the United States in 1963 for the first time and subsequently revised several times until the final version F209E in 1992. In the absence of an international standard, for many years the FS209E was used internationally.There are thirteen classifications of air cleanliness from class M1 to M7 as shown in the FS209E table below.The standard also indicates the conditions in accordance to which the controls must be carried out:
- as built: Clean rooms or clean zones ready to start operating but without production equipment and personnel.
- as rest: Clean rooms or clean zones fitted with the relevant processing machines but without personnel
- operational: Clean rooms or clean zones in ordinary working activities with personnel and running processing machines.
This standard also determines the characteristics of the air flow, distinguishing between unidirectional (instead of linear) and non unidirectional flow (instead of turbulent).It establishes the conditions for the measurement of particles and the instruments to use.
ISO 14644.1
The need for a new international standard that covered more cleanroom environmental parameters and practices led to the formation of a technical committee of the International Standards Organisation. In 1996 ISO (International Standards Organisation) issued a new standard ISO 14644.1 with the goal of standardisation of equipment, facilities and operational methods for cleanrooms and controlled environments.
Comparison of International Standards
Standard and Date Published
| USA 209D (1988) | USA 209E (1992) | EEC CGMP (1998) | EN ISO14644-1 (1999) | Germany VD 12083 (1990) |
| ISO 1 | ||||
| ISO 2 | ||||
| 1 | M1.5 | ISO 3 | 1 | |
| 10 | M2.5 | ISO 4 | 2 | |
| 100 | M3.5 | A & B | ISO 5 | 3 |
| 1,000 | M4.5 | ISO 6 | 4 | |
| 10,000 | M5.5 | C | ISO 7 | 5 |
| 100,000 | M6.5 | D | ISO 8 | 6 |
Federal Standard 209E
| Fed.Std | Max. Number of Particles/ m³ equal or above | |||||
| 209E | 0.1µm | 0.2µm | 0.3µm | 0.5µm | 1µm | 5µm |
| M1 | 350 | 75.7 | 30.9 | 10 | ||
| M1.5 | 1,240 | 265 | 106 | 35.3 | ||
| M2 | 3,500 | 757 | 309 | 100 | ||
| M2.5 | 12,400 | 2,650 | 1,609 | 353 | ||
| M3 | 35,000 | 7,570 | 3,090 | 1,000 | ||
| M3.5 | 26,500 | 10,900 | 3,530 | |||
| M4 | 75,700 | 30,900 | 10,000 | |||
| M4.5 | 35,300 | 247 | ||||
| M5 | 100,000 | 618 | ||||
| M5.5 | 353,000 | 2,470 | ||||
| M6 | 1,000,000 | 6,180 | ||||
| M6.5 | 3,530,000 | 24,700 | ||||
| M7 | 10,000,000 | 61,800 | ||||
Cleanroom Classification according to EN ISO 14644-1
| ISO Class | Max. Number of Particles/ m³ equal or above | |||||
| 0.1µm | 0.2µm | 0.3µm | 0.5µm | 1µm | 5µm | |
| 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 | 295 |
| 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 | |||
GMP Guidelines – In addition to the ISO standard the Good Manufacturing Practice Guidelines are also applicable for pharmaceutical, food, cosmetic and medical applications.
| EUG GMP Class | Max. Number of Particles/ m³ equal or above | |||
| GMP | At Rest | In Operation | ||
| Class | 0.5µm | 5µm | 0.5µm | 5µm |
| A | 3,520 | 20 | 3,520 | 20 |
| B | 3,520 | 29 | 352,000 | 2,900 |
| C | 352,000 | 2,900 | 3,520,000 | 29,000 |
| D | 3,520,000 | 29,000 | ||
