All new temperature-controlled storage areas must be temperature-mapped as part of a fully documented verification process, before the installation is commissioned and handed over by the installer. Until this has been done, it is not safe to store TTSPPs in such areas.
The temperature mapping procedures should:

  • Demonstrate the air temperature profile throughout the storage area, when empty and in a normal loaded condition;
  • Define zones which should not be used for storage of Time and Temperature-Sensitive Pharmaceutical Product (for example areas in close proximity to cooling coils, cold air streams or heat sources); and
  • Demonstrate the time taken for temperatures to exceed the designated limits in the event of power failure.

Subsequent mapping exercises must also be carried out on a periodic basis – for example, every three years – in order to demonstrate continuing compliance.

In addition mapping should be carried out whenever significant modifications are made to the store.

Examples include changes in the pattern of use that may increase loading or affect air circulation, or changes to the refrigeration equipment, such as an alteration to the set point. Finally a remapping exercise may be justified whenever an analysis of temperature and/or humidity monitoring records show unexplained variability outside normal operating limits.
All mapping exercises should be fully documented in order to demonstrate compliance to management, clients and the regulatory authorities.


Section 4.7 of WHO Technical Report Series No. 961, 2011