What we have written on the cold chain55 / 154

Do not treat source count as a vote. Compare codes, revisions, measurement conditions and written manufacturer confirmation.

Dry ice sublimates at -78.5 °C and releases gas. We work out how much CO2 10 kg of dry ice produces in a closed cargo space, set it against the ADR limits, and show where a gel pack belongs.

Annex II Chapter IV is seven short points and applies to all food transport. The last one shapes cold chain equipment: temperature must be held and it must be possible to monitor it.

An instant pack, a gel pack and a GEBHARDT eutectic plate differ in filling, in the risk to goods they touch and in the first decision: what to record at delivery, how cold the replacement plate must be frozen, and which records decide acceptance.

Phase point alone is not a selection criterion: ask for test conditions, cycling data and exact product match.

The product's outer carton, a washable divider or a suitable disposable board can serve as the separator; freeze sensitivity, moisture, airflow and lid closure decide the choice.

Verify the terms against a system diagram, then compare temperature records on the same route and load.

Yes: a product surface can freeze near a pack while average air looks acceptable. The lower limit, product points and layout are tested together.

The UNICEF Supply Catalogue publishes cold box cold life together with its test condition: +43 °C ambient, frozen ice packs, the moment the inside reaches +10 °C. The same yardstick works for anyone writing a specification.

A hard surface, frost and an elapsed-time record do not show that the filling is solid. GEBHARDT's criterion: filling completely frozen, freezer at least 5 °C below the melting point, air gap between plates.

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

Ice packs stacked into a tight block freeze late in the middle. Layering them on a rack that keeps an air gap between packs works fine.