For pharmaceuticals, chip manufacturing , precision engineering, optics and so on. It is important that a certain level of cleanliness of the production space is observed. The same goes for a number of medical facilities. Therefore, such a characteristic as the class of cleanliness of the premises was introduced. Its detailed definition, as well as the formula for the permissible concentration of impurities in clean air, the classification features will be presented below.
What is the cleanliness class
The cleanliness class of enclosed spaces (rooms) is a characteristic of the cleanliness of indoor air, as well as strictly defined requirements for the proportion of microparticles and various impurities in the air. Between themselves, these classes differ in the number of a certain particle size per a given unit volume.
Cleanliness classes 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 the air
To determine how much air in the test room 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 cleanliness of the room; it is customary to round to an integer (particles / m 3 ).
- N is the classification number of the purity class - a value from 1 to 9; intermediate numbers are rounded to a maximum of 0.1. You can choose this number for the class you need from the standard tables given in this article.
- 0.1 is a constant number (μm).
- D - specific size, particle diameter (μm).
Classes of cleanliness of industrial premises
Let us imagine the cleanliness classes necessary for a certain type of production. The table uses the class codes introduced by ISO ( International Organization for Standardization).
| Class | Name of production |
| ISO 3 | Integrated circuits |
| ISO 4 | Integrated circuits with a gap between conductors of less than 2 microns |
| ISO 5 | Absolutely sterile injection production, requiring no suspended particles and microorganisms in the air |
| ISO 6 | - Upscale optical elements
- Mini Bearing Assembly
- Testing and assembly of high-precision gyroscopes
|
| ISO 7 | - Precision pneumatics, mechanical engineering, hydraulics
- Assembly of high-precision pneumatic, hydraulic equipment, clock mechanisms, as well as high-quality transmissions and servo-driven valves
|
ISO 8 | - Automotive
- Manufacture of plastics
- Assembly of various electronics, devices with hydraulic or pneumatic installations
|
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 purity classes that are used to evaluate the rooms in which sterile medicinal substances are produced.
| Class | Zone feature |
| A | The area where filling takes place directly, blockage of the container with the drug, as well as other operations with a high probability of causing irreparable harm to the quality of the drug |
| IN | The area located in close proximity to location A; place of preparation of solutions |
| C and D | Premises where less important stages of sterile production take place. This also includes areas where work is carried out with components after washing. |
The maximum number of suspended particles per cubic meter of air for each class can be found in the following table.
As you have seen, for every responsible production premises of a certain level of purity are required. In medical institutions, a slightly different classification is used - we turn to it.
Cleanliness classes in medical facilities
Finally, we present four classes of cleanliness of medical facilities.
| Class | Premises | The total number of microorganisms CFU (colony forming unit - viable bacterium) / m 3
| Number of molds, CFU / m 3
| The number of staphylococcus colonies,
CFU / m 3
|
| before work | during work | before work | during work | before work | during work |
| Very clean | - Halls: operating rooms, maternity
- Sterile boxes: for premature babies, burns, hematological patients, as well as pharmacies, bacteriological laboratories
- Sterilization rooms
| > 200 | > 500 | No | No | No | No |
| Clean | - Chambers: dressing, procedural, resuscitation, preoperative
- Clinical and baclaboratory
- Packing pharmacies
| > 500 | > 750 | No | No | No | No |
| Relatively clean | - Infectious and surgical wards
- Pantries with clean linen
- Ording
| > 750 | > 1000 | No | No | No | No |
| Dirty | Corridors, stairs, office buildings, toilets, etc. | Not standardized |
The class of cleanliness of the premises is a necessary characteristic for determining the air pollution of a given enclosed space. The quality of many types of products is directly affected by the cleanliness of the production room. In a medical institution, the success of treatment, the general condition and even the lives of patients depend on it.