In July a pangasius processor in southern Vietnam loaded 20 tonnes of frozen fillets into a 40GP and described the cargo as general goods with coolant. The container arrived in Los Angeles with a core temperature of minus 8°C. The buyer rejected it, the cargo was downgraded, and the insurance file closed without payment: a dry container has no cooling, no airflow and no temperature record, so there was nothing to prove and nothing to claim.
Five hundred kilos of dry ice had been added as a "cold source". Dry ice is Class 9 dangerous goods, it was never declared, and in a sealed steel box it displaces oxygen while cooling unevenly. Two problems in one container, both avoidable at the booking stage.
The rule: temperature control is a chain, and a dry box is not on it
A reefer is not a cold box; it is a machine with a power supply, a set point, an air circulation path and a recorder. The carrier runs a pre-trip inspection, plugs the unit on board, and holds the set point for the voyage. None of that exists in a dry container, and no amount of ice substitutes for it over eleven days at sea.
Three booking windows, counted backwards
- Equipment and PTI: 7–10 days. Reefer stock is thinner than dry stock and a pre-trip inspection has to be booked with the depot. In peak season, allow 14 days; a 40RH is not a 40HQ.
- Set point and plug confirmation: 5–7 days. The carrier must confirm the temperature, the ventilation setting and the plug position. Change the set point after the cut-off and the booking usually rolls.
- Pre-cooling and loading: 24–48 hours. The cargo must already be at its carrying temperature before it goes in, and the box should be pre-cooled. Loading warm cargo and waiting for the machine to pull it down is how a claim starts.
The stow: airflow first, then lashing
A reefer cools from the floor up through the T-grating and returns air along the ceiling. Anything that blocks the floor or the door end breaks that loop, and the back of the container stays warm while the sensor near the unit reads normal.
- Stack no higher than the red load line. Above it the return air is blocked and the top layer warms.
- Keep pallets flush and square, with no overhang into the side wall airflow.
- Leave 10–15 cm clear at the door end, and never stack against the door.
- Lash with straps to the floor rings or use dunnage bars; frozen cartons slide, and a shifted load blocks the return air.
- Close, seal, and start the recorder before the box leaves the plant.
What the file has to contain
| Document | Who issues it | What it settles |
|---|---|---|
| PTI report | Depot or carrier | That the unit worked before loading |
| Set point confirmation | Carrier | Temperature, ventilation and plug on board |
| Pre-loading temperature record | Shipper, with photos | That cargo was at temperature at hand-over |
| Health or phytosanitary certificate | Competent authority | Import admissibility at destination |
| Cold treatment schedule | Carrier or authority | Where a protocol temperature is required |
| Seal number and loading photos | Shipper | Condition at the moment the box closed |
The loading checklist, eight steps
- Confirm the commodity, its carrying temperature and whether a cold treatment protocol applies.
- Book the reefer and the PTI, and confirm the plug with the carrier in writing.
- Pre-cool the container to the set point before loading starts.
- Check the cargo core temperature at the plant and photograph the reading.
- Load to the red line, pallets square, airflow path clear.
- Lash, then check that nothing has moved into the return air.
- Close the doors, apply the seal, start the recorder, photograph the seal.
- Send the PTI, the set point confirmation and the loading photos with the shipping instructions.
Six places this goes wrong
- Loading warm cargo and relying on the machine to pull it down: it cannot, and the recorder proves it.
- Using dry ice as the only cold source: Class 9, undeclared, and uneven.
- Stacking above the load line, which blocks the return air.
- Pallets that cover the floor grating at the door end.
- Assuming the plug was confirmed because the booking was accepted.
- Leaving without a copy of the temperature download.
A plain note from the desk: a reefer does not fix a warm cargo, it only holds a temperature that was already there. Check the core temperature at the plant, load to the line, and keep the recorder — that is the whole discipline.
Before the next reefer booking, send us the commodity, the required temperature, the volume and your target sailing on WhatsApp. We will confirm the equipment window, the set point and the document list before the booking is placed, not after the box is packed.