Controlled atmosphere shipping for produce

Controlled atmosphere is a reefer specification that actively manages the gas mix inside the container — oxygen down to a few per cent, carbon dioxide up — to slow the fruit’s respiration and extend how long it stays saleable.

Fruit does not stop living when it is picked. It burns its own sugars, gives off carbon dioxide, heat and ethylene, and softens as it goes. Cold slows that down; taking away most of the oxygen slows it further. A CA unit holds the mix there for the whole voyage, either by scrubbing and injecting or by drawing nitrogen through a membrane, correcting continuously as the cargo and the box leak.

CA is not modified atmosphere #

Modified atmosphere means the gas mix was set once — usually by a liner or a bag, sometimes by nothing more than the fruit’s own respiration inside a sealed pallet cover — and then left to drift. It is cheaper, it does real work, and it is common on bananas and avocados.

Controlled atmosphere is the active version: instruments, control, and a mix that is still correct in week five. On voyages long enough to matter, that difference is the point.

What it costs you, and what it costs if it is wrong #

CA is ordered and paid for before the doors close, per container, and it cannot be added at sea or at a transshipment hub. It also constrains equipment: not every box in a line’s fleet is CA-capable, so a CA booking is a smaller pool of containers to allocate from.

The recipe is commodity-specific and getting it wrong damages fruit rather than simply wasting money. Too little oxygen and the fruit ferments and tastes of it. Too much carbon dioxide and you get CO₂ injury — browning and off-flavours that appear at destination and nowhere earlier. Blueberries, cherries, apples and kiwifruit all travel under CA and none of them want the same numbers.

FAQ #

Is controlled atmosphere worth paying for? #

On fast-respiring fruit over a long voyage, usually — several trades exist only because CA made the transit survivable. On a short lane with a tolerant commodity it is cost without much return.

Can CA rescue a delayed shipment? #

Only if it was already booked. CA slows the clock rather than stopping it, and it has to be specified before loading — which is exactly when nobody knows the routing is about to change.

Does CA replace getting the temperature right? #

No. It works on top of a correct setpoint and properly pre-cooled fruit. A CA container running at the wrong temperature is an expensive way to arrive with the same problem.