Reefer container settings for frozen fruit: temperature, vents, loading

In a reefer container frozen fruit ships at a set-point of −18 °C or colder with the fresh-air vent closed, stowed as one tight block below the red load line. The set-point and carton count go on the booking and the bill of lading. In a claim, the evidence is the carrier’s controller record, and only the shipper named on the B/L can request it.

What temperature should a reefer be set to for frozen fruit?

Set the controller to −18 °C or colder. That figure comes from Codex CXC 8-1976, the Code of Practice for quick-frozen foods, which calls for storage at −18 °C or colder. The code was formerly numbered CAC/RCP 8-1976, and older documents still use that number. Many shippers set −20 °C to leave a margin above the product, but that is trade practice and no standard requires it.

Two Vietnamese texts use the same number. The first is the Vietnam–China protocol on frozen durian, issued through the Plant Protection Department (Cục Bảo vệ thực vật) of the Ministry of Agriculture and Rural Development. It came into force on 19 August 2024 for five years and renews automatically for five more. It requires freezing at ≤ −35 °C for at least one hour, until the product core reaches ≤ −18 °C. After that, the product must be held at ≤ −18 °C continuously in storage and transport, in accordance with CAC/RCP 8-1976. The second is TCVN 13941:2023, the Vietnamese standard for frozen passion fruit, which sets storage at “không lớn hơn −18 °C”, meaning not warmer than −18 °C. It covers pulp, purée, juice and concentrate.

No Codex, USDA or EU marketing standard exists for quick-frozen tropical fruit. Vietnam has adopted Codex CXS 320-2015 as TCVN 11511:2024, but that standard covers vegetables. The temperature clause in a frozen-fruit contract therefore comes from the general Codex code, or from the buyer.

A reefer holds temperature. It does not pull it down. Britannia P&I makes this point in its reefer cargo guidance: the product has to be at temperature when it enters the box. For the documents that travel with a frozen lot, see the frozen durian HS code and document set.

Where is −18 °C measured, and why does the contract have to say?

A contract that writes only “−18 °C” has not said which of three readings it means. It could be the controller set-point, the air temperature in the carrier’s record, or the product core measured by drilling. Each one fails in a different way.

The Vietnam–China frozen-durian protocol and Codex CXC 8-1976 part at the difference between the protocol’s “continuously” and the code’s −12 °C. The durian protocol says ≤ −18 °C continuously in transport. The Codex code it adopts allows the warmest package to reach −12 °C during distribution, a 6 °C band that the protocol’s wording does not mention. Neither text says whether a reading is taken from air or product, at which carton, or for how long. If a lot arrives with return air at −15 °C for six hours and cores at −17 °C, one reading of the documents finds a breach and the other does not. The contract has to settle this before loading, because no one can settle it afterwards. Codex CXS 75-1981, for quick-frozen peaches, adds one useful rule: quick freezing is complete only when the core reaches −18 °C after thermal stabilisation. A carton that is −18 °C on the surface and warmer inside has not been frozen to specification.

How a lot is sampled for these readings is covered in pre-shipment sampling for frozen fruit.

Should the fresh-air vent be open or closed for frozen fruit?

Closed. Standard practice for frozen cargo is to run the reefer with the fresh-air vent shut. Frozen fruit does not respire, so outside air brings in only heat and moisture, and the moisture ends up as frost on the cartons and the evaporator coil.

Fresh produce is the opposite case. Fresh banana runs at a set-point of 13.5 ± 0.5 °C with 15–25 m³/h of fresh air, because the fruit gives off CO₂ and ethylene, which have to be vented. A banana claim can fail on “correct temperature, wrong ventilation”: if the vents are shut on a respiring cargo, the seller can be blamed for the instruction.

The same mistake in reverse shows up on a frozen load. The carrier’s record logs the ventilation rate, so a vent left open on frozen fruit will be visible in the data. Write the setting as “fresh-air vent: closed” on the booking. Do not leave it to the terminal.

How should frozen fruit be stowed inside a 40-foot reefer?

Stow frozen cartons as one solid block, with no gaps between them. Chilled air from the supply chute moves along the T-bar floor and around the outside of the block. A tight block leaves little warm air inside the load and few surfaces exposed to it. Fresh cargo is stowed the other way, with channels left open so air can pass through the produce. Never load above the red load line on the side walls, whatever the cargo. Cartons above the line block the return-air path and the top tier warms first.

Never put fresh and frozen cargo in one container. Fresh dragon fruit runs at +5 to +8 °C and frozen fruit at −18 °C, and no single set-point serves both.

Condition at stuffing matters more than the box. Packing IQF at ambient temperature causes case hardening, clumping and large ice crystals, and one countermeasure is a packing room at 10 °C or below. Whether to pre-cool the empty container before stuffing is an instruction to take from the carrier for that specific unit. The advice in circulation conflicts, and the answer depends on how the box is loaded.

Short, repeated power interruptions during transhipment, yard moves or vessel changes are more common than one long failure. Partial thaw followed by refreezing is one of three root causes of clumped IQF fruit. The other two are in the factory: wet product entering the tunnel, and an overloaded tunnel. Clumps that appear only at destination point to temperature abuse after the factory, which the controller record can confirm or rule out. How the freezing method itself affects clumping is set out in IQF versus BQF.

What goes on the booking and the bill of lading?

The booking and the B/L should carry the set-point, the ventilation setting and the humidity setting, so the instruction exists in writing before the box is plugged in. This is trade practice rather than a legal requirement, and it is what a surveyor compares against the controller record. Britannia P&I advises checking at loading that the set-point on the unit matches the carriage instructions. It also advises having the pre-trip inspection (PTI) done by a competent person on the carrier’s behalf.

Three further entries pay for themselves:

1. The carton count, not just the container. “1 x 40’RF STC 1,333 cartons” is better than “1 container”. Under the Hague-Visby Rules the carrier’s liability limit is 666.67 SDR per package or 2 SDR per kg, whichever is higher. The per-package figure applies only when packages are counted on the B/L. That is the international convention figure. Vietnam’s Maritime Code 2015 has not been checked against this figure.
2. The load port terminal, not just the port. Plug-in charges and waiting times differ between terminals in the same port.
3. The shipper’s name, chosen deliberately. The next section explains why this entry decides who holds the evidence.

Which temperature record settles a reefer claim?

The carrier’s record settles a reefer claim. A shipper’s data logger is useful as a warning, but it may not be accepted as evidence.

Reefer units typically keep their own controller record, often downloaded as a DataCorder report. According to Britannia P&I’s 2022 guidance on reefer cargo care and claims, that record typically holds:

• power on and off dates and times
• PTI data
• alarms triggered
• supply and return air temperatures
• humidity, ventilation rate and CO₂

Britannia P&I’s guidance also warns that readings from a logger placed by the shipper may not be accepted as evidence, depending on the contract of carriage. A logger records only the air where it sits, and its position in the load changes the reading. Only the shipper named on the bill of lading can request the carrier’s record directly. A seller on FOB terms who is not the B/L shipper has to go through the buyer. The choice between FOB and CFR therefore decides who controls the evidence when a reefer arrives warm.

VinFruits Global contracts so that the party controlling the container between load port and discharge is the party named as shipper on the bill of lading, because the right to obtain the carrier’s temperature record follows the name on that document.

Loggers still belong in the load. Draft contract clauses differ on placement; one approach puts them at three positions: near the door, mid-load and at the far end. Use their readings for early warning and negotiation. Build the claim on the carrier’s download. Request it in writing, quoting the container number, the B/L number and the voyage dates. Ask for a full DataCorder report for the entire voyage, including power events, alarms, the PTI record, and supply and return air. Ask the carrier to preserve the data and to keep the unit out of repair or a new PTI until the download is done, because the controller can be overwritten. Reserve rights in the same letter. Name the independent surveyor in the contract before any dispute; SGS, Vinacontrol, Bureau Veritas and CCIC all handle reefer cases.

How do you read the carrier’s record after an incident?

Each pattern in the carrier’s controller record points to a likely cause and a likely party, and of the five common patterns below, three point to the seller rather than the carrier.

A buyer reading the record should expect it to show the condition of the lot at the factory gate as well as the voyage. Under CISG Article 36(1), the seller is liable for a lack of conformity that existed when risk passed, even if it appears later. Vietnam has been a party to the CISG since 1 January 2017.

Does cargo insurance cover a reefer breakdown?

Not under the standard clauses. Institute Cargo Clauses (A), (B) and (C) of 1/1/2009 do not cover damage caused by refrigeration breakdown. All three share the same exclusions for insufficiency or unsuitability of packing or preparation, which extends to stowage in a container, for inherent vice (cl. 4.4) and for delay (cl. 4.5). Stowage that blocks reefer airflow can fall under the packing exclusion.

Breakdown cover needs the Institute Frozen/Chilled Food Clauses. The Joint Cargo Committee’s 2017 revision replaced the 1986 clauses and comes in four forms: the Frozen/Chilled Food Extension Clauses, Clauses (A), Clauses (A) – 24 Hour Breakdown, and Clauses (C). The 1986 clauses covered machinery breakdown “resulting in its stoppage for a period of not less than 24 consecutive hours”. That trigger sits poorly with short, repeated interruptions, which are more common than a single long failure. The 2017 revision also excludes claims where more than 60 days pass between the cargo first entering the freezing chamber and the start of cover. IQF fruit frozen in season and shipped months later can fall outside the policy before it leaves the cold store.

Under Incoterms® 2020, CIF requires the seller to buy only ICC (C), and CIP requires ICC (A). Neither covers a breakdown without the Frozen/Chilled clauses. Name the clauses, and the form, in the sales contract.

What excursion should a frozen-fruit contract allow before rejection?

No published rule sets a threshold and duration for reefer excursions on frozen tropical fruit, so the contract has to set one. The Codex warmest-package limit of −12 °C is the outer boundary. Draft contract clauses differ, and settle the question in three different ways:

• reject if the temperature stays above −15 °C for more than four continuous hours, with the temperature record required among the payment documents;
• reject if a logger at any of three positions shows a breach of −12 °C, with no duration stated;
• treat a core temperature warmer than −12 °C as a critical defect: zero tolerance, lot rejected.

The three tests are not equivalent. The first is an air-temperature test with a time limit. The third is a product test with none. A storage tolerance written as “−18 °C or colder, fluctuation ≤ ± __ °C” is common, and published sources contradict each other on the right figure. The buyer’s own shelf-life study is the only sound basis for it. A complete clause states three things: the threshold, the measuring point (air or core, at which position), and the duration.

Common questions

What temperature should a reefer be set to for frozen fruit?

Set the reefer to −18 °C or colder, the storage temperature in Codex CXC 8-1976. Many shippers choose −20 °C to leave a margin above the product. The reefer only holds temperature, so the fruit must already be at −18 °C or colder at the core when it is loaded. The set-point should be written on both the booking and the bill of lading.

Should the fresh-air vent be open or closed for frozen fruit?

Closed. Frozen fruit does not respire, so outside air adds only heat and moisture, which turns to frost on cartons and the evaporator coil. Fresh produce such as banana needs vents open, around 15–25 m³/h. The carrier’s controller record logs the ventilation rate, so a vent left open on a frozen load will show up in a claim.

Is my own data logger enough evidence in a reefer claim?

Often not. Britannia P&I warns that a shipper’s logger may not be accepted as evidence, depending on the contract of carriage, because its reading depends on where it sits in the load. The claim should rest on the carrier’s controller download, which logs power events, alarms and supply and return air. Only the shipper named on the bill of lading can request that download directly.

Does all-risks cargo insurance cover a reefer breakdown?

No. Institute Cargo Clauses (A) of 2009 do not cover damage caused by refrigeration breakdown. That needs the Institute Frozen/Chilled Food Clauses 2017, which come in four forms. The 2017 clauses exclude claims where more than 60 days pass between the cargo entering the freezer and the start of cover, which matters for IQF fruit held in cold storage before shipment.

What excursion should a frozen-fruit contract allow before rejection?

No published rule exists for frozen tropical fruit. The contract sets the threshold, the measuring point and the duration. The outer limit is the Codex CXC 8-1976 rule that the warmest package must not exceed −12 °C in distribution. Draft contract clauses differ: some reject above −15 °C for four hours, while others reject any core or logger reading warmer than −12 °C.