TT Talk - Common issues in the cool chain

Whilst perishable cargo is often valuable freight, it can also give rise to higher exposures, which should provide adequate incentive for extra care to be taken by all stakeholders.

As the world's specialised 'reefer ship' fleet continues to decline, it is estimated that containers are today utilised for up to 75% of all temperature controlled cargo shipments. The process of correctly packing, handling and monitoring both equipment and cargo is one that will continue to demand attention. 

Insuring this supply chain process, TT Club has considerable experience in understanding how things can go wrong.  The majority of insurance claims involving perishable cargo are found to occur due to:

  1. Confusion over Celsius and Fahrenheit
  2. Poor communication of requirements (plus versus minus temperatures)
  3. Failure to monitor or plug in the cargo transport unit throughout its journey.

Instances of ambient cargoes, such as bread and chocolate, being mistakenly shipped in deep freeze conditions or conversely cargoes of fish and animal carcasses requiring to be shipped under deep freeze conditions below -18DegC, arriving with the consignee at +18DegC are all too common. Inevitably, these simple mistakes result in a dramatic deterioration of the cargo, leading to claims of total loss and often disposal costs.

"Often the simplest of errors result in high value losses"

There are innumerable opportunities throughout a supply chain for such errors. Often the simplest of errors result in high value losses.  Foodstuffs especially are subject to stringent restrictions to ensure safety through the food chain.  These will often dictate that even the smallest abuse in temperature can result in the refusal of cargo, condemned as unfit for consumption. Similarly, many pharmaceuticals are sensitive to temperature deviations.

For all stakeholders in the cool supply chain, it is vital to know your customer when handling temperature controlled cargoes. Under the IMO/ILO/UNECE Code of practice for Packing Cargo Transport Units it is the responsibility of the shipper to define specific instructions and requirements regarding the transport of the cargo.  This responsibility may be passed to a logistics service provider, not least when full supply chain managed operations are undertaken.  Whatever the circumstance the logistics provider should actively seek clarification and agreement from the shipper regarding all requirements, and contracts specifying this information should be regularly checked, especially at renewal.  It should also be noted that industry regulations - and therefore transport requirements - have the potential to change for perishable cargoes fairly regularly.

For the majority of cargoes, the shipper will normally specify a set temperature at which the cargo is to be maintained throughout the duration of the transit.  For less sensitive chilled cargoes, a range of acceptable temperatures may be stipulated.  In either case, when sub-contracting transport moves, whether short inter-depot transfers or global containerised movements, it is essential to ensure that clear and accurate written instructions are passed down the contractual chain.  The margins for error are often very small, the difference between "-" and "+" temperature can be easily confused in communications and will likely have catastrophic effects on the cargo.

While the Celcius scale is most commonly used globally, certain regions (such as USA) or trades may utilise Fahrenheit. Adding to the confusion, 0°C is a widely recognised temperature setting for chilled cargoes, whilst 0°F is a widely recognised temperature setting for frozen cargoes. Again accurate communication is key to avoiding potential losses. 

Once the shipping instructions have been made clear, the container needs to be functioning properly.  Reefer equipment should be regularly inspected for conformity, especially prior to loading and such units should be serviced and maintained regularly. Visual checks for damage should also be carried out prior to packing.  Damage to the internal vents, perhaps caused by previous poor packing, can severely affect the efficiency of air flow through the transport unit, which in turn can result in a failure to reach the set point temperature. 

It is also essential to check regularly that the data logger equipment is fully functional. It is now possible to monitor this data remotely and for warnings to be raised when temperatures fluctuate unexpectedly. However, such technology is of little value if the data logger itself is not operational.

"Time is of the essence and can have a dramatic effect in mitigating a loss."

Pre-packing checks and correct packing play an important role.  The CTU operator is responsible for ensuring that the provided CTU is in good condition, clean and free from odour.  The packer also needs to be satisfied that the unit is clean1. The cargo must be evenly distributed with due care taken to ensure a free flow of air and pallets stacked safely and securely.  Crucially, cargo should be cooled to the desired carrying temperature prior to loading; cargo packed at elevated temperatures is unlikely to achieve the desired setting and is at risk of rejection by the consignee.

Whilst prevention is better than cure, if things do go wrong when dealing with temperature sensitive cargoes, time is of the essence and can have a dramatic effect in mitigating a loss. Early appointment of an expert to assess a cargo alleged to have suffered temperature abuse can often result in at least a portion of the cargo being either accepted or saved by means of a salvage sale. Further, there are specialist distressed cargo service providers able to perform micro-biological analysis on cargo to determine whether or not it is safe to enter the food chain

We hope that you will have found the above interesting. If you would like further information, or have any comments, please email us, or take this opportunity to forward to any colleagues who you may feel would be interested.

We look forward to hearing from you.

Peregrine Storrs-Fox
Risk Management Director, TT Club


1  See the Joint industry guidelines on container cleanliness

Staff Author

TT Club