What we have written on the cold chain108 / 154

How many minutes a lid may stay open depends on the product limit and on the number of openings on the route. Below: the temperature limits in the regulation, a total open-time calculation and a field logging step.

The longest step is freezing the plates: GEBHARDT's table recommends 24 hours for every plate, and it runs overnight. The order of everything else decides how much of the morning is lost.

An insulated carrier does not replace preparation equipment. Verify the product, container and transport conditions against their procedures.

Decide on preconditioning from model instructions, loading process and measured trials, not a fixed time assumption.

Find the heat-gain path in the measurements, then compare container design and plate load in a controlled trial.

Choose placement from the container model, load plan and product's sensitivity to freezing.

Both work by phase change. Two questions decide: does the container come back, and at what temperature must the product stay. Gel packs for one-way parcels, eutectic plates for returnable containers and frozen goods.

Contact zones can differ from general container readings. Document load marks, packaging and product measurements together.

When freezing, an air gap between plates and the freezer temperature decide the result; when transporting, cold air sinking decides where the plate goes. Read the numbers against the melting point.

A suspect plate leaves service and is not patched and returned. Below: the most liquid a plate can release, the records to keep and the food law behind the decision.

Do not generalise fluid composition across products or plates. Check the label and SDS, document possible contact and obtain a quality decision.

If a plate changes shape or is wet, isolate it from use. Record its ID, observations and potentially exposed load, then contact your supplier.