Reefer Containers & Cold Chain: A Guide to Shipping Frozen and Chilled Food

Frozen meat, seafood, dairy, fruit and vegetables all depend on one thing during international transport: an unbroken cold chain. A refrigerated container, usually called a reefer, is the standard way to move these goods by sea, but a reefer only maintains temperature. It does not fix product that was warm when it was loaded. This guide sets out the practical points professional buyers and suppliers should agree before a temperature-controlled shipment is booked.

Understand what a reefer does and does not do

A reefer container has its own refrigeration unit and insulated walls, and it circulates air to hold a set temperature. It is designed to keep cargo at the right temperature, not to cool warm cargo down. Cargo should therefore arrive at the port already at the required temperature, which means the cold chain has to be managed from the cold store through trucking, port handling and loading.

Agree the temperature requirement in writing

Do not rely on general terms such as "frozen" or "chilled". Write down the required carriage temperature, the acceptable range, and the product temperature at loading. Frozen and chilled products need very different settings, and some fresh products are sensitive to being held too cold. Ask the supplier for the product's recommended carriage temperature and confirm it against your own specification and any rules in the destination market. Also state whether the unit should run in chilled or frozen mode and whether fresh-air ventilation should be open or closed, since this depends on the cargo.

Pre-cool the container and check the product at loading

Good practice is to inspect the container before loading, confirm it is clean and odour-free, and pre-cool it to the setpoint. At loading, the supplier or an independent inspector should record product core temperatures, check packaging for damage, and confirm that cartons are stowed so air can circulate around and through the load. Blocking the air return or loading above the marked load line is a common cause of uneven temperatures.

Use monitoring and keep the records

Most reefer units log set and return air temperatures, and many shipments also carry independent data loggers inside the cargo. Agree in advance who supplies the loggers, who downloads the data and how it will be shared. These records are the main evidence if a claim is needed later, so ask for them to be retained for the full journey, including any time spent waiting at ports or in transit between modes.

Plan the documents and the handover

Temperature-controlled food usually travels with the standard commercial documents plus product-specific papers, for example a health or veterinary certificate where the destination requires one. Requirements vary by product and country, so confirm them with your customs broker before the goods ship. Delays at the destination port are especially costly for cold cargo because the unit needs continuous power and electricity charges can accumulate. Agree who pays for plugged-in time, demurrage and detention, and choose a trade term that matches where you want the risk to transfer, as covered in our guide to Incoterms for wholesale food buyers.

Insure the cargo and qualify your partners

Ask your insurer whether the policy covers temperature deviation and reefer machinery breakdown, because standard cargo cover may not. It also pays to work with suppliers and logistics partners whose food safety systems you have checked. Our supplier qualification checklist is a useful starting point.

Start your next temperature-controlled order

Sentrick Foods is a B2B wholesale food marketplace connecting verified suppliers, professional buyers and logistics and customs partners worldwide. If you are planning a frozen or chilled purchase, see how buyers use Sentrick Foods to request quotes from suppliers.