Knowledge / Testing and the packing process
Qualifying Thermal Packaging: Test Plans and Evidence
Qualification demonstrates that a particular thermal packaging system is suitable for its intended use. The shipper, cooling elements, preparation, packout and payload are tested under defined conditions. The test plan describes these conditions and defines in advance what constitutes a pass.
Practical guidance
Which payloads and sensor positions belong in the test, and what must the test report document?
Test setup with sensor leads. Sensor positions and attachment belong in the test documentation.
In this guide
- Define what the test should demonstrate before starting
- What DQ, OQ and PQ each assess
- Document the complete test configuration
- Test small and large payloads, summer and winter
- Assign measurements correctly and assess borderline results
- Derive permitted shipping conditions from the report
- Use existing reports and add targeted tests
- Assess changes before the next shipment
Define what the test should demonstrate before starting
Record temperature limits, required duration, ambient temperature profile, initial temperatures and permitted payloads in the test plan. Add the pass criteria, often called acceptance criteria: which measurement locations must maintain which limits, and for how long?
Have the test plan and responsibilities approved before starting. The result can then be assessed against predefined criteria.
What DQ, OQ and PQ each assess
| Stage | Purpose |
|---|---|
| DQ – Design Qualification | Demonstrate that the planned packaging concept can meet the specified requirements. |
| OQ – Operational Qualification | Demonstrate under controlled conditions that the configuration reproducibly delivers the required performance. |
| PQ – Performance Qualification | Demonstrate that the system is suitable in the intended real shipping operation. |
WHO describes these stages for shipping containers. Suitable supplier evidence can cover parts of the testing. Document which data are adopted and why they are applicable to your use. Your quality system defines the scope of testing and responsibilities.
The comparison of ISTA and AFNOR explains the role of a standardised temperature profile.
Document the complete test configuration
- Item numbers, variants and drawings of the components used.
- Coolant pack preparation: temperature, duration, equipment loading and time until packing.
- Product or substitute payload, including initial temperature, mass and arrangement.
- Ambient temperature profile and duration, including intended waiting periods and opening events.
- Measuring equipment, calibration status, recording interval and precise sensor positions.
- Acceptance criteria, repetitions and the procedure for deviations.
Justify measurement locations at potential warm and cold product positions. Photographs and dimensions help reproduce the configuration later. The resulting packing instructions for shipping must use the same components and positions.
Test small and large payloads, summer and winter
One possible test matrix combines warm and cold ambient temperatures with the smallest and largest permitted loads. This is not a general requirement for exactly four tests: additional cases and repetitions are justified in the test plan on the basis of risk.
Also consider unfavourable initial temperatures, long waits before collection and foreseeable changes in shipper orientation. A full shipper can block air paths or bring goods closer to the edge. A small product quantity can warm or cool faster. An empty shipper also has different thermal properties and, without investigation, is not the worst case for every load.
For substitute products, document composition, fill quantity, containers and arrangement. The same total weight as the goods is insufficient to demonstrate comparable temperature behaviour.
Assign measurements correctly and assess borderline results
Distinguish between measurements of the surroundings, the air in the product compartment and the product surface or interior. These temperatures can respond at different rates. An air measurement therefore cannot be used to infer the temperature of every container without justification.
Record sensor position, attachment, calibration status and measurement interval. If a value is close to the permitted limit, apply the rule for measurement uncertainty defined in advance. Retrospective rounding must not conceal a limit breach.
The report should show the relevant individual temperature histories and deviations. An average across all sensors is insufficient if it conceals a product position that is too cold or too warm.
Derive permitted shipping conditions from the report
After the test, record which configurations, product quantities, initial temperatures and transport durations are covered. Include conditions for waiting times and handling. Transfer this information into packing instructions and training.
During trials in real shipping, check whether preparation, handovers and transport occur as planned. New seasonal data, complaints or changes may require reassessment. A one-off climate chamber test does not automatically apply to every subsequent use.
Use existing reports and add targeted tests
Place the supplier report alongside your requirements. Highlight differences such as a longer shipping duration, different packs, a different product quantity or additional intermediate storage. Assess their effect before adopting the report.
An additional test should answer the specific outstanding question. If a smaller load is being added, for example, simply repeating the unchanged full-load test offers little benefit. Simulations can support test selection, but require suitable data and a verified model.
The packaging selection guide provides advice on requesting and comparing these documents.
Assess changes before the next shipment
Document the approved configuration and revision. If components, supplier, preparation, payload or transport lane change, assess the potential effect on temperature maintenance. This determines whether existing evidence is sufficient or further testing is needed.
For reusable systems, ageing, damage and replacement of components belong in this assessment. The report and work instructions must make clear when a system may be reused.
Sources
- WHO: Qualification of shipping containers, Supplement 13 (2015). Sections 2.1–2.5: development, qualification and reuse of shipping containers.
Sources checked on 12 September 2026.
Discuss your testing requirements with THERMOCON
Gather product requirements, payload variants and available transport data. Our thermal engineering team can use these to discuss the test configuration and any missing evidence.