Temperature sets the life of fresh fish. In the examples FAO gives, salmon that lasts 11.8 days at 0 °C lasts 8 days at 5 °C and 3 days at 10 °C; packed cod falls from 14 days to 6 and then 3. The target is therefore a temperature close to that of melting ice, and the Turkish Regulation on Specific Hygiene Rules for Food of Animal Origin requires fresh fishery products to be stored (Article 51) and transported (Article 52) at that temperature.
Ice is worked out from two items. The ice needed to bring lean fish to 0 °C is fish mass times the fish's starting temperature divided by 100: about 10 kg for 100 kg of fish at 10 °C. The second item is the ice that absorbs heat entering through the box wall; it grows with time and outside temperature, and in FAO's words the insulated container keeps the ice.
Meltwater must not collect under the product. The regulation requires that meltwater does not touch fish transported under ice (Article 52). The inner tub of the GEBHARDT TBX Seafood holds 24 litres and has a meltwater drain at the rear; for the smaller TBX 725 and 795 there is an 18-litre stainless tub as an accessory.
