What are the GDP requirements for temperature mapping of pharmaceutical warehouses?

GDP and USP <1079.4> require warehouses to be mapped before use and re-mapped when risk factors justify it. The temperature mapping study must use calibrated sensors and a documented protocol with predefined acceptance criteria and rationale. Results are used to show the warehouse maintains labelled conditions and to identify where permanent monitoring sensors should be placed.

• Initial mapping: Perform before first use under representative conditions. WHO guidance indicates 7–14 days is typical, but the duration must be justified by risk.
• Calibrated equipment: Use sensors calibrated at relevant points, traceable to national standards.
• Protocol approval: Define objectives, acceptance criteria, sensor plan, duration, and reporting.
• Risk-based requalification: Repeat after changes in layout, HVAC, storage capacity, or if trend data indicates instability. Also see: Eliminate re-mapping with the continuous mapping framework.

How to design a GDP warehouse mapping protocol

A protocol sets the foundation for a compliant study. It should be approved before execution, and the scope, acceptance criteria, responsibilities, equipment, and tests should be defined. Including a rationale for sensor count and placement is expected by regulators.

Also see: GxP-compliant temperature mapping equipment

• Objectives: Show that the warehouse maintains labelled ranges and identify hot and cold spots.
• Scope: Define areas, temperature ranges, and exclusions.
• Acceptance criteria: Predefine allowable variability, maximum excursions, and duration with documented rationale.
• Sensor plan: Justify the number and placement based on risk, volume, and layout. Learn more: "Data logger calculator for mapping: How many do you need for your warehouse?"
• Test conditions: Define representative operating conditions; include door openings and power interruptions if risk warrants.
• Duration: Explain and justify study length, typically 7–14 days or as risk dictates. Regulators expect justification if seasonal studies are not performed.

Download a free GDP warehouse mapping protocol template here ✅

How to execute a GDP warehouse temperature mapping

Execution must follow the approved protocol, and careful planning at this stage prevents audit findings. Teams should coordinate installation, verification, and documentation in a structured manner. Many regulators expect that every action is recorded, deviations are addressed, and that the analysis provides clear evidence that the warehouse is fit for purpose.

• Installation: Mount sensors securely, label them, and record their positions in a location plan that is archived with the study.

• Data integrity: Synchronize clocks, protect data, and ensure audit trail following ALCOA+ principles (Attributable, Legible, Contemporaneous, Original, Accurate, plus Complete, Consistent, Enduring, Available).

• Verification: Check sensor functionality and calibration certificates before starting, and document the checks.

• Deviations: Document any departures from protocol, explain root cause, and assess potential impact on study validity.

• Analysis: Evaluate variability, excursions, and whether acceptance criteria were met; document statistical methods if applied.

• Hot/cold spots: Identify and document locations for permanent monitoring and provide rationale for final recommendations.

Also read: Temperature mapping: tips, frameworks, and pitfalls

How to report GDP warehouse temperature mapping results

Reporting should demonstrate that the study followed the protocol, show results against acceptance criteria, and include recommendations for [monitoring](/temperature-monitoring). Reports should be signed and approved by Quality (QA), archived in the quality system, and available for audits.

• Protocol adherence: Confirm that execution followed the approved plan.
• Results: Present temperature profiles, excursions, and variability.
• Acceptance decision: State whether the warehouse met the criteria, with a rationale.
• Recommendations: Translate findings into monitoring placement and alarm limits.

Also read: Continuous temperature mapping – eliminate re-mappings with Eupry