Clean area classification.

  Clean area classification.

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• The clean or buffer room is the secondary engineering control. 

• It houses the primary engineering controls (the LAFH, BSC, or CA) where the aseptic compounding is actually performed. 

• Clean room is a specially constructed enclosed area, which contains one or more clean zones, where the concentration of airborne particles is controlled using HEPA filters, continuous air circulation, and a physical barrier to non-filtered (or outside) air. 

• Clean rooms establish appropriate environmental levels for airborne particulates, temperature, humidity, air pressure, and airflow patterns. 

• Clean rooms are categorised by their constant air quality or class. 

Clean rooms are rated as given in table:  

(Lower the classification number, cleaner is the air.)

Clean Room	Properties
Class 10,000 (ISO class 7)	10,000 or less particles of 0.5 µ and larger size exist in a given cubic foot of air.
Class 1,000 (ISO class 6)	1,000 or less particles of 0.5 µ and larger size exist in a given cubic foot of air.
Class 100 (ISO class 5)	100 or less particles of 0.5 µ and larger size exist in a given cubic foot of air.

• Apart from the above mentioned basic components, a clean room also includes: 

• 1) UV irradiation, 

• 2) Air-lock entry portals, 

• 3) Special filtration or treatment systems for incoming air, 

• 4) Sticky mats for removing particulate matter from shoes, and 

• 5) Positive room air pressure for controlling entry of contaminants from adjacent rooms.