Law, Health and Safety
Cleanroom class: definition, tables, formulas
For pharmaceuticals, microcircuits, precision engineering, optics and so on. It is important to maintain a certain level of cleanliness of the production space. The same is true for a number of medical institutions. Therefore, such a characteristic as the class of cleanliness of premises was introduced. Its detailed definition, as well as formulas for the permissible concentration of impurities in pure air, the classification features will be presented later.
What is the class of cleanliness of premises
The class of cleanliness of enclosed spaces (rooms) is a characteristic of the cleanliness of the air in the room, as well as strictly defined requirements for the proportion of microparticles and various impurities in the air. These classes differ among themselves in the number of a certain particle size by a given unit of volume.
Classes of cleanliness of cleanrooms are established by the following documents:
- GOST R 52249-2009;
- GOST R ISO 14644-1-2002.
The formula for determining the concentration of particles in air
To determine how much air in the room under test corresponds to the purity class necessary for it, use the following formula:
C n = 10 N x (0.1 / D) 2.08, where:
- C n - the maximum permitted concentration of substances for a certain class of room cleanliness; It is customary to round it up to an integer (particles / m 3 ).
- N - classification number of the class of purity - value from 1 to 9; Intermediate numbers are rounded up to a maximum of 0.1. You can select this number for the class you need from the table-standards given in this article.
- 0,1 is a number-constant (μm).
- D is the specific size, particle diameter (μm).
Classes of cleanliness of industrial premises
We represent the classes of purity necessary for a certain type of production. The table uses class codes introduced by ISO (ISO) - the International Organization for Standardization.
| Class | Name of production |
| ISO 3 | Integrated Circuits |
| ISO 4 | Integrated microcircuits with a conductor spacing of less than 2 μm |
| ISO 5 | Absolutely sterile injection production, which requires the absence of suspended particles and microorganisms in the air |
| ISO 6 |
|
| ISO 7 |
|
ISO 8 |
|
The maximum permissible number of impurities and particles of different sizes per 1 m 3 of room air for a certain class is shown in the photo.
Now consider the classes of purity that are used to assess the premises in which sterile medicinal substances are produced.
| Class | Zone characteristic |
| A | The area where the filling takes place directly, the blockage of the container with the drug, as well as other operations with a high probability of irreparable harm to the quality of the drug |
| AT | The zone in the immediate vicinity of location A; Place of preparation of solutions |
| C and D | Premises where less important stages of sterile production take place. This also includes the areas where the components are handled after washing |
With the limiting number of suspended particles per cubic meter of air for each class, you can see the following table.
As you saw, for each responsible production, premises of a certain level of purity are required. In medical institutions a slightly different classification is used - let us turn to it.
Classes of purity in medical institutions
Finally, we will present four classes of cleanliness of medical premises.
| Class | Premises | The total number of microorganisms, CFU (colony-forming unit - a viable bacterium) / m 3 | Number of molds, CFU / m 3 | Number of colonies of staphylococci, CFU / m 3 | |||
| before work | While working | before work | While working | before work | While working | ||
| Particularly clean |
| > 200 | > 500 | No | No | No | No |
| Clean |
| > 500 | > 750 | No | No | No | No |
| Conditionally clean |
| > 750 | > 1000 | No | No | No | No |
| Dirty | Corridors, stairs, administrative premises, toilets and so on. | Not standardized | |||||
The class of cleanliness of premises is a necessary characteristic for determining the air pollution of a particular enclosed space. The quality of many products is directly influenced by the purity of the production premises. In the medical institution, the success of treatment, the general condition and even the life of patients depend on it.
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