Thursday 21 February 2013

Cleanrooms and Air Quality – A Risk-Based Approach

Cleanrooms are highly controlled environments where the air quality is monitored to ensure the extreme standards of cleanliness required for the manufacture of pharmaceutical, electronic, and healthcare goods. These stringent standards usually require high fresh air rates, extensive filtering, temperature, and humidity control - all of which results in increased energy usage.

Protection from uncontrolled ingress of external ambient air is achieved by creating a pressure differential between the cleanroom and its surroundings. Contamination control is the primary consideration in cleanroom design; however, the relationships between contamination control and airflow are not well understood. Contaminants such as particles or microbes are primarily introduced to cleanrooms by people, although processes in cleanrooms may also introduce contamination. During periods of inactivity or when people are not present, it is possible to reduce airflow and maintain cleanliness conditions.

In relation to the risk assessment of cleanrooms, Tim Sandle has written a free-to-view online paper. Access it here: Sandle cleanrooms.

Posted by Tim Sandle


  1. Hello Tim,
    you are absolutely right monitoring a pressure differential is essential between cleanrooms and its surrondings.

    my question is that for air flow pattern it is recommended to perform Smoke studies.

    do you have any study available which can guide me how it can be performed and which smoke is recommended to check air flow pattern in clean room environment.

    looking forward .

    Section Head - Sterile Department

  2. Hi Tim,
    you are absolutely right that it is important to monitor pressure differential between grade A and Grade B rooms.

    i have one question that if we have see the air flow pattern we perform smoke studies.

    do you have any data which can support how to perform smoke studies and which smoke is mentioned in clean rooms to check air flow pattern , as i think dry ice or propylene glycol is not recommended.

    i need help from you regarding smoke studies in clean rooms.

    looking forward Tim,


    Section Head - Sterile

  3. Raheel,
    Please let me have your email address, and I'll send you some information.


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