Temperature mapping for GDP storage
Mapping warehouse storage so the client could show an inspector that product is held inside its labelled conditions.
The situation
Warehouse storage for medicinal products: a racked ambient area and cold rooms held at 2 to 8 °C, with loading doors on one side and heating and cooling that run to their own cycles, not to the product.
What had to be shown
Good Distribution Practice expects a storage area to be mapped before it is used and again after any significant change, and the results to decide where the permanent monitoring goes. The client needed that evidence for their Responsible Person and for inspection, and needed it to survive questions about where the loggers were and why.
How I did it
- Walked the site first. Sensor positions came from the risks, not a tidy grid: loading doors, external walls, the top and bottom of the racking, and the air outlets.
- Placed calibrated data loggers in three dimensions across the racking heights, following the WHO guidance on temperature mapping, each traceable to national standards.
- Ran the study over a full working week including a weekend, so door traffic and the heating and cooling cycles were all in the data, and planned a second study for the opposite season.
- Reported the minimum, maximum and mean for every position, identified the hot and cold spots, and recommended where the permanent monitoring probes should sit.
What the client got
A mapping report the client’s quality team could put in front of an inspector: where the storage holds its range, where it does not, and permanent monitoring placed on the positions that matter rather than wherever was convenient to cable.
Written from the work, with no client named and no client figures quoted.