Perishables in air freight: where it goes wrong and how to prevent it
Short answer: with perishables in air freight, things rarely go wrong during the flight itself. The risks lie in ground handling. Make sure the cargo departs at temperature, cover the top and add cooling when the route is long.
Perishables is the term used in air freight for perishable cargo: fruit and vegetables, flowers and plants, fish and seafood, meat and pharma shipments. What they have in common is that they have a temperature window outside which quality drops irreparably.
Where it goes wrong
Not in the air. The cargo hold is generally cool. The vulnerable moments are in ground handling: the drive to the terminal, waiting on the platform, loading and unloading, and again at a stopover. Those are the hours in which a pallet can stand in the sun.
An air freight shipment is therefore a chain of links. One weak link is enough to damage the whole shipment. That is why it pays to look at each link separately.
The chain step by step
- At your cold store. The cargo should be at temperature here and stay that way until the last moment.
- The drive to the airport. If the truck is not refrigerated, every extra hour of waiting time counts.
- Acceptance and storage at the handler. Here the pallet sometimes waits for hours. Ask in advance whether a cold room is available and how long the cargo may stand there.
- Platform and loading. The most dangerous stretch, especially in sun or on a warm day.
- Flight and any transfer. A transfer means ground handling again.
- Arrival and delivery. Here too, the pallet may wait before the recipient collects it.
The more transitions, the more moments when the cargo stands outside cooling. A direct flight with short waiting times is often the safer choice for vulnerable cargo.
Fruit and vegetables
These products breathe and in doing so produce heat themselves. A tightly built pallet that goes into the flight too warm keeps warming up from the inside. Some types give off ethylene, which speeds up the ripening of other products. Staying at temperature here is therefore quality preservation and shelf life preservation.
Flowers and plants
Cut flowers are extremely sensitive to temperature peaks. A few hours too warm costs vase life, and the buyer only notices days later, at the end customer. This is a segment where temperature damage becomes visible with a delay. You can read more about this segment in transporting flowers under refrigeration.
Fish and seafood
Here every degree counts immediately. Fish is almost always shipped with a coolant in the box, and the cover around it determines how long that coolant lasts. Leak-proof packaging is also practically important here, because liquid in a cargo hold quickly causes problems. Also read chilled shipping for fish and seafood.
Pharma
The strictest segment, with documented temperature windows and a recording obligation. A thermal cover is rarely the only measure here, but it is an important layer between the cold store and the cargo hold. Which requirements apply to your product is determined by your principal or quality department. We only describe what our packaging does: slow down warming.
The common denominator
The same applies to all these cargo types: make sure the cargo goes into the cover at temperature, cover the top where the radiant heat enters, and add cooling in the load itself when the route is long. The cover slows warming, but does not cool. How best to build the pallet itself is covered in building a pallet for air freight.
Checklist before you ship
- Was the cargo packed at temperature, in the cold space?
- Is the pallet built tightly, without voids and within the pallet dimensions?
- Does the cover fall over the top and fit properly at the bottom?
- Is there cooling in the load if the transit time could run long?
- Is there a data logger included, so that you can see afterwards what happened in transit?
- Does the handler know that the cargo is temperature-sensitive and how quickly it must be processed?
Questions to put to your freight forwarder in advance
Good preparation starts with the right questions. Ask them before the cargo is under way, not afterwards.
- How long does the pallet stand on the platform at most before loading?
- Is there a cold room at the handler, and is the pallet really put in it?
- What is the shortest routing, and are there stopovers or transfers?
- Who takes delivery of the pallet at the receiving end, and when?
- What happens in the event of a delay, and who calls you then?
Measuring is knowing
On a new route, place a data logger in the pallet. Then you see where the temperature curve deviates and can adjust in a targeted way. Measure the first shipments on a new route and not only when there is damage. With that data you can also talk to your freight forwarder about the weak link.
Frequently asked questions
Does a thermal cover keep my cargo cold?
No, a cover does not cool. It slows warming. The actual holding time depends on the outside temperature, the starting temperature of the load and any cooling elements. More about this can be found in how long does a thermal cover keep the load at temperature.
Should I also insulate the base?
On long routes or with a warm floor, that is advisable. Heat also rises from the ground.
What if the flight is delayed?
Then the time on the platform or in storage increases. For the cooling in the load, therefore, always allow some extra time and discuss with your freight forwarder how delays are handled.
Straight to the range
Take a look at our thermal pallet covers and the selection for air freight. You can find more about our approach for this sector on the page cold chain packaging for air freight and air cargo.
