Seed Cake Sows Confusion

A number of recent incidents have highlighted the considerable confusion around carriage of seed cake, particularly given its nature to self-heat which can lead to combustion. This article aims to clarify the carriage requirements for Members and vessel crew.

What is Seed Cake?

Seed cake is the residue remaining after the oil has been extracted from oil-bearing seeds, cereals or similar products. This cargo is most commonly shipped for use as animal feed or biofuel. A long list of the products which seed cake can be derived from is listed in the International Maritime Solid Bulk Cargoes Code (IMSBC). The IMSBC Code requirements are summarised opposite.

Oil is extracted either by mechanically crushing the seeds or by the use of a solvent. The method of extraction and the percentage of oil and moisture remaining will determine the category of the seed cake.

IMSBC Code Schedules

Currently there are four schedules of seed cake listed in the IMSBC 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 table below summarises the requirements of these schedules. This MUST be read in conjunction with the Code.

All seed cake schedules with a UN number fall into IMDG Code Class 4.2 – substances liable to spontaneous combustion and are categorised as Group B – cargoes which possess a chemical hazard. This can include self-heating or oxidation.

Due to the additional risks associated with Group B cargoes, these must be listed on a vessels document of compliance for the carriage of solid bulk cargoes. Where they are not listed, permission should be obtained from the vessel’s Flag State. Permission may not be granted if suitable firefighting equipment is not fitted.

Only certain products can be carried under the seed cake (non-hazardous) schedule of the Code. These products must be in the specific form listed and must meet strict limits regarding oil and moisture content. Any difference in form, method of extraction, or oil and moisture content, will mean that cargo should not be carried as a seed cake (non-hazardous).

Temperature checks should be carried out before loading to ensure that the cargo is less than 55°C, or the ambient temperature plus 10°C, whichever is lower. Temperature checks should also take place during the voyage.  

The graph to the right shows the oil and moisture limits for Group B seed cake cargoes.

Documentation

Before loading, a suitable cargo declaration should be provided. This should state the schedule to which the cargo applies.   It should include oil and moisture content as well as the method of extraction. Moisture and oil content affects the chemical properties of the cargo. A certificate must be provided stating the oil and moisture content. Provided the cargo is accurately declared and is carried in accordance with the IMSBC Code, then it can be loaded and shipped without incident.   We trust this article is of assistance but remember always refer to the relevant IMSBC Code schedule.