The carriage of seed cake cargoes under the IMSBC Code 2020 Edition
With thanks to Daniel Sheard of Brookes Bell for his contribution to this article.
Commodities such as soya bean meal, sunflower seed pellets, palm kernel expellers, and others have been shipped for many years in large volumes. These are the solid residues left behind when oil is removed from oil-bearing seeds. They can self-heat and some are spontaneously combustible.
Previous editions of the IMSBC Code have contained four schedules relevant to the carriage of seed cake cargoes in bulk, all with the Bulk Cargo Shipping Name incorporating “SEED CAKE”. Three of these were Group B cargoes being Class 4.2 spontaneous combustible, and one was a Group C cargo - SEED CAKE (non-hazardous).
With the introduction of the 2020 Edition of the IMSBC Code, becoming mandatory in January 2021, there are a number of changes. The schedules which have UN Numbers retain the name “seed cake” – we have SEED CAKE UN 1386(a), SEED CAKE UN 1386(b), and there is SEED CAKE UN 2217.
The new edition of the Code introduces two entirely new schedules headed “SEED CAKES AND OTHER RESIDUES OF PROCESSED OILY VEGETABLES”. All five schedules in the 2020 IMSBC Code (three SEED CAKE schedules and two “SEED CAKES AND OTHER RESIDUES OF PROCESSED OILY VEGETABLES”) should be taken as encompassing any processed plant material with residual oil and moisture. The applicable schedule should be selected based on the properties of the material, not whether it happens to be a produced by extraction of oil from seeds.
The two new schedules relate respectively to hazardous Group B cargoes designated MHB (material hazardous only when in bulk) and to Group C cargoes (non-chemically hazardous). Which category is correct depends on how hazardous the material is in terms of tendency to self-heat.
The relevant test to evaluate this is a UN standard test known as the N4 test in which a cube of the commodity in question is held at high temperature in an oven and any increase in sample temperature above the oven temperature is measured.
Many commonly encountered seed cake cargoes such as soya bean meal and sunflower seed pellets will be carried under the Group C “SEED CAKES AND OTHER RESIDUES OF PROCESSED OILY VEGETABLES” schedule. Carriage under this schedule requires that the vessel is provided with certification confirming that the material in question has been tested in the N4 test and does not meet the MHB self-heating criteria. As this type of certification has not previously been required, members are recommended to be vigilant in scrutinising documentation when asked to load a cargo under thus schedule.
Member should also note that although these schedules include cargoes in the Group C “non-hazardous” category, experience shows that they can still self-heat on board ships and cargo damage can result. It is also worth remembering that if fuel oil tanks immediately adjacent to such cargoes are overheated, any of these commodities can be ignited as a consequence. Fires tend to be slow-burning and do not spread readily, but they can be challenging to extinguish.
We would finally remind all involved in the carriage of these materials that all seed cake cargoes can cause oxygen depletion in enclosed spaces. No entry into enclosed space containing any seed cake cargo should take place without thorough checks having been carried out that the atmosphere within is safe for breathing.
100mm sample cube used for N4 test
There is in broad terms a hierarchy of hazard across the five schedules as per the diagram below.
Heated soya bean meal cargo
Heated and discoloured seed cake cargo (corn gluten feed)
Fire in corn gluten feed