Seed Cake Sows Confusion

What is Seed Cake?

Seed cake is the name given to the residues remaining after oil-bearing plant matter has been either mechanically crushed or treated with solvents to remove the oil. The seed cake is commonly transported in bulk for use as a feedstuff, predominately for livestock.

Is it a Grain Cargo?

No – natural grain products, or products which have not undergone any form of processing, must be loaded and carried in accordance with the requirements of the International Code for the Safe Carriage of Grain in Bulk, whereas seed cake cargoes must be loaded and carried in accordance with the requirements of the International Maritime Solid Bulk Cargoes Code (the IMSBC Code).

The IMSBC Code contains an extensive list of the products from which seed cake is derived that are included within four individual schedules in the Code:

• Seed cake, containing vegetable oil UN 1386 (a) mechanically expelled seeds, containing more than 10% of oil or more than 20% of oil and moisture combined
• Seed cake, containing vegetable oil UN 1386 (b) solvent extractions and expelled seeds, containing not more than 10% of oil and when the amount of moisture is higher than 10% not more than 20% of oil and moisture combined
• Seed cake, UN 2217 with not more than 1.5% oil and not more than 11% moisture 
• Seed cake (non-hazardous).

The particular schedule a seed cake cargo will fall under is therefore determined by the method in which the oil was extracted and the percentage of oil and moisture remaining in the cargo. 

What are the Hazards?

Self-heating and oxygen depletion. With the exception of Seed cake, (non-hazardous) which is categorised as a Group C cargo, all seed cake cargoes fall into IMDG Code Class 4.2 – substances liable to spontaneous combustion and are categorised as Group B, known to possess a chemical hazard, as there is the potential for self-heating.

Self-heating of the cargo is initially caused by microbiological activity, driven by the inherent moisture content. Therefore the higher the moisture content the higher the risk of self-heating occurring. This can cause the temperature to rise to a point where oxidation of residual oil can occur which can in turn cause further self-heating to occur. The oxidation of residual oils can result in a reduction in the oxygen content within the atmosphere of cargo holds and surrounding spaces with the subsequent risks to personnel.

What Problems Do We See?

The carriage of seed cake cargoes regularly creates confusion both with regards to the requirements for carriage on a vessel and with the requirements for documentation. Some of this confusion arises due to cargoes being incorrectly declared as a natural grain product rather than a residue remaining after processing. These cargoes have very different carriage and documentary requirements.

A number of incidents have been reported where a cargo that was declared as seed cake, (non-hazardous) has self-heated during the voyage. This has usually been as a result of the cargo not meeting the requirements of the exemption due to excessive oil and or moisture content.

Localised damage to cargo has also been noted where cargo has been loaded over heated fuel tanks, against hot bulkheads or where hold lighting has been left on after loading.

Check the Documentation

It is essential that the cargo is properly declared in order that the potential risks associated with carriage can be adequately assessed and the precautions for its safe carriage to be taken. The declaration should state, as a minimum, which schedule the cargo will fall under, the method of extraction and should be provided to the Master prior to commencing loading.

If in doubt about any aspect of the documentation ask the shippers for clarification. If you are still in doubt please do not hesitate to contact the club for advice.

Further Information

A new Loss Prevention Briefing on the “Carriage of Seed Cake” has been produced.

In addition to defining what constitutes a seed cake cargo and outlining the IMSBC Code requirements for differing seed cake cargoes, the briefing outlines the hazards associated with these cargoes and the documentation required.

A copy of the briefing can be read here.