The qualification of a cleanroom is a crucial process to ensure that the air quality meets the required standards. The term “recovery time” refers to the ability of a cleanroom to quickly return to its original state after a malfunction.

Recovery time

The relevant guidelines for cleanroom qualification and recovery time include ISO standard 14644 and the GMP (Good Manufacturing Practice) guidelines. These standards define the requirements for air cleanliness, the classification of cleanrooms and the methods for qualifying and monitoring cleanroom quality.
Tests and measurements are carried out to evaluate the recovery time of a cleanroom. This includes, for example, measuring particle concentrations in the air before and after a controlled disturbance using cleanroom-compatible aerosols. The recovery time of the cleanroom provides information on how long a cleanroom meets the defined cleanliness requirements again after certain events, such as after a fire alarm or other unexpected events. Regular inspections and measurements can ensure the efficiency and effectiveness of the ventilation and air conditioning system.
The recovery time is determined individually by the respective company, taking into account the risk analysis.

Overall, recovery time is an important aspect of cleanroom qualification. Regular monitoring is therefore essential.


  • DIN EN ISO 14644-1
  • EU GMP Annes 1

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