Cleanroom

The European Union has created the ISO 14644-1 cleanroom standard. The standard contains nine purity classifications, of which ISO 1 is the purest.

The Good Manufacturing Practice guideline (GMP) is a classification designed to ensure the safety and reliability of the product. The GMP classification includes all manufacturing-related matters, such as raw materials, equipment, facilities, staff hygiene and training.

GMP is divided into categories A, B, C and D purity:

• A-rated spaces are very clean areas and correspond to the ISO 4.8 purity class. These facilities are reserved for critical steps in the process. In the pharmaceutical industry, for example, the packaging of medicinal products takes place in a class A cleanroom.

• B-rated space usually surrounds class A mode. B is a state of aseptic or sterile work.

• Category C corresponds to the ISO 7 classification. A C-purity class cleanroom is an area where less critical steps of the process can be carried out.

• Category C corresponds to the ISO 8 classification. Like class C, D-rated spaces are less suitable for critical work.

Ventilation plays the greatest role in keeping the cleanroom pure.

The air conditioner regulates the temperature and humidity of the cleanroom. In addition, a separate High Efficiency Particulate Air Filter (HEPA) is required. The cleanroom classification determines how many HEPA filters must be in the facility.

There is always overpressure in the cleanroom, allowing air to flow from a clean space to one that is more contaminated. Also, the amount of air in the space is high, relative to the size of the facility. In this way, the particles are removed from the space while the air changes.

Cleanrooms are given special attention in ensuring efficient air circulation. The convection air is first removed from the facility, after which it is brought back to the cleanroom via filters. The convection air contains some clean outdoor air.