How to interpret a WHO PQS cold-life value

A cold-life value depends on the specific product model and test setup; it is not a guarantee for every box or real route.

24 April 2026Updated 23 September 2026

Short answer

WHO PQS E004/CB05.4 gives freeze-preventive vaccine cold boxes loaded to no more than 50 kg minimum cold life of 48 hours for the short-range category and 96 hours for long-range at +43°C in the test. These are test minima for the stated category and model, not a guarantee for all passive boxes or field routes.

WHO PQS E004/CB05.4 specifies minimum cold life at +43°C of 48 hours for short-range and 96 hours for long-range freeze-preventive vaccine cold boxes loaded to no more than 50 kg. These are category minima; the headline condition cannot be generalised to all passive boxes.

Ask the supplier for PQS product code, model, report or specification version, load type, conditioning and lid-opening conditions. Match the value to the exact configuration on the data sheet; do not transfer it to a similarly named model.

On an actual route, log stops, openings, ambient conditions and sensor location under product instructions. Keep PQS results separate from field records; do not base product release only on a catalogue cold-life duration.