Temperature recording for GxP environments

The consequences of inadequate temperature recording are concrete and costly. EU GDP Chapter 3 requires documented evidence of controlled storage conditions throughout the supply chain. WHO TRS 961 Annex 9 sets the standard for monitoring during distribution. USP <1079> is explicit: product degradation from excursions is cumulative and not reversible.

When gaps appear in your temperature data - whether from a logger that ran out of battery, a manual download that happened two days late, or a sensor placed at the wrong height - the consequences follow a predictable pattern. An auditor flags the gap. You open a deviation. You write a CAPA. You spend days reconstructing what actually happened in that cold room or shipment. In the worst case, you cannot reconstruct it at all, and product release is blocked.

Fragmented processes make this worse. Organizations running 15, 25, or 50 separate vendor relationships for temperature recording across shipping, cold rooms, and lab freezers face the same problem at every level: disconnected data, manual reconciliation, and no single source of truth when it matters most.

All of the loggers have proven their worth and saved precious samples on several occasions when freezers broke or were accidentally left open.

Anja Pomowski, Senior Scientist at Antikor

The contrast between traditional and continuous temperature recording is not abstract. The numbers tell the story directly.

Traditional setup

A data logger is placed in a storage area or shipment. It records at intervals, typically every 3 to 5 minutes. At the end of the study or shipping event, someone physically retrieves the logger, downloads the data via USB, and imports it into a separate system for analysis. For ongoing monitoring, 5 loggers cover the identified hot and cold spots. Re-validation happens every 2 to 3 years, or after any significant operational change. Each re-validation means pulling 100 loggers, running a full mapping study, and waiting for a report that is already aging by the time it is approved.

Continuous recording with Eupry

WiFi-based sensors transmit data automatically. No manual downloads. No retrieval trips. The system is always on, always uploading, and always audit-ready. Eupry's continuous mapping approach uses 15 to 20 room temperature recorders instead of 100, covering all identified risk zones permanently. Re-validation is triggered by operational changes, not by a calendar. Data is encrypted with AES-256 storage and TLS 1.3 transfer, with 5-year backup - meeting long-term retention requirements without manual archiving.

The result: fewer loggers, fewer manual steps, fewer gaps. Your compliance documentation is current the moment an inspector walks in.

Most problems in temperature recording programs are not caused by bad intent. They are caused by structures that make the right thing harder than the wrong thing. These three mistakes appear most often.

• Placing sensors in the wrong locations. Horizontal-only placement misses vertical stratification. WHO TRS 961 Annex 9 recommends specific spacing per area size - one sensor per 10 square meters for small rooms, one per 30 for larger spaces. Skipping a three-dimensional grid means your worst zones may never be recorded. A sensor placed at eye level in a walk-in cold room tells you nothing about conditions at floor level or above 3 meters.
• Treating the initial mapping study as permanent. A one-time snapshot is not a compliance program. EU GDP Chapter 3 requires requalification after layout changes, HVAC modifications, or capacity shifts. Organizations that file the original mapping report and move on are running on outdated data - and they typically discover this when something goes wrong, not before.
• Falling into the complacency trap. Continuous recording reduces the daily burden of compliance, but it does not eliminate the need for periodic review. Things change: airflow patterns shift, new product lines require different setpoints, staff replace sensors without updating the risk assessment. Parking temperature compliance in the "taken care of" pile and never reviewing the framework is a vulnerability, not a solution.