Freight glossaryEquipmentContainersTrucking
Reefer
Definition
A reefer is a refrigerated container or trailer with its own cooling unit, used to move freight that must stay at a controlled temperature.
What it means
A global forwarder describes reefer containers as used "to transport goods requiring temperature-controlled conditions in transit."[1] Maersk lists a temperature range of -30 °C to +30 °C for its standard 20-ft and 40-ft high cube reefers, with special units that go colder.[2]
Insulation and the cooling unit take space. One carrier lists its 40-ft high cube reefer at 11,584 x 2,294 x 2,557 mm inside, noticeably smaller than a 40-ft high cube dry box, with the figures given as non-contractual.[3] For food, temperature records matter at delivery: under FDA's sanitary transportation rule, food showing a possible temperature-control failure may not be sold or distributed until a qualified individual decides it was not made unsafe.[4]
Example
A 40-ft reefer of produce is set to 2 °C at origin. At delivery the receiver checks the unit's temperature record before accepting it, because the food shipper's quality team has to clear any excursion first.
Related
Related terms
- Shipping ContainerA shipping container is a standardized steel box, most often 20 or 40 feet long and 8 feet wide, built to...Glossary
- Dry VanA dry van is an enclosed, non-refrigerated box trailer for general freight; the 53-ft dry van is the most...Glossary
- 40-ft High Cube ContainerA 40-ft high cube container is a 40-ft shipping container that is 9 feet 6 inches tall, one foot taller than...Glossary
Sources
- DSV, “What is a reefer container?,” Forwarder publication. Accessed September 30, 2026.
- Maersk, “What is the temperature range of a reefer container?,” Carrier FAQ. Accessed September 30, 2026.
- CMA CGM, “Reefer Technical Specifications,” Carrier equipment specification. Accessed September 30, 2026.
- Legal Information Institute, Cornell Law School, “21 CFR § 1.908, Requirements for the sanitary transportation of human and animal food,” Federal regulation. Accessed September 2026.
General operational information, not legal, customs or regulatory advice. Rules and rates change; confirm current requirements with the agency, carrier or contract that governs your shipment.