Temperature mapping audit readiness check

EU GDP and ISPE require a mapping before a space is taken into use. Without an initial mapping, the suitability of the space has not been demonstrated.

The mapping must reflect actual use – including door openings, loading, typical ambient temperatures. A study under ideal conditions only is difficult to defend.

Acceptance criteria (e.g. all points within 2–8 °C) must be set in the protocol before execution, not after seeing the results.

Duration must be long enough to capture representative conditions. For fridges/freezers typically 24–72 h; for GDP warehouses typically 7 consecutive days including a weekend.

The location of the warmest and coldest points must be identified and documented. These determine where products can and cannot be stored.

The routine monitoring sensor must be placed at or near the worst-case location identified by mapping – not just wherever is convenient.

Data loggers must be calibrated before use and the certificates must be traceable to national standards. Calibration certificates are part of the dossier.

The dossier must include a protocol, data, analysis and a clear conclusion on whether the space is suitable for its intended use.

After changes to HVAC, layout, load or use, the need for requalification must be assessed. A change that affects temperature distribution requires a new study.

Temperature distribution can differ significantly between summer and winter. GDP guidance expects seasonal mapping or a justified risk assessment when only one season is studied.

There must be a procedure for handling temperature deviations and alarms – including who acts, when, and how it is documented.

All raw measurement data and calibration certificates must be kept – not just the summary report. Auditors may request original data.