Rapeseed meal is a Group B cargo under the IMSBC Code, carried as a seed cake under UN 1386 or UN 2217 depending on residual oil and moisture content. The self-heating hazard from oxidizing vegetable oil makes misdeclaration the primary risk: cargoes presented as non-hazardous have reached 80°C during loading operations, requiring emergency discharge. Amendment 05-19, in force from 1 January 2021, restructured all seed cake schedules and tightened certification requirements.
What rapeseed meal is and how it is produced
Rapeseed meal is the solid residue left after vegetable oil is extracted from rapeseed seeds, also marketed as canola when derived from low-erucic-acid, low-glucosinolate cultivars. Rapeseed is the seed of Brassica napus (and closely related species), an annual oilseed crop. The seed contains 37% to 46% oil by weight; the remaining protein-rich press cake or extracted meal is the commodity shipped in bulk.
Oil extraction follows one of three industrial routes, each producing a meal with a different residual oil content:
Mechanical expeller pressing uses a continuous screw press to squeeze oil out of heated or cold seed. The friction from the screw raises the seed temperature during pressing. Cold-pressed rapeseed cake retains 16% to 20% residual oil. Hot-pressed expeller cake retains roughly 4% oil. Mechanical pressing does not remove all oil; it is the highest-oil product and therefore the highest-risk cargo for self-heating.
Solvent extraction uses hexane (or occasionally alternative solvents) to dissolve the remaining oil from the pre-pressed cake. After solvent recovery by evaporation, the extracted meal contains less than 1% residual oil. Large industrial crush plants typically pre-press the seed to remove the bulk of the oil, then pass the press cake through a solvent extractor to bring the final meal to below 1% oil. This combined pre-press/solvent-extract route dominates global commercial production.
Double extraction refers to full solvent extraction without pre-pressing, used in some smaller operations. The resulting product also comes in below 1% oil.
Rapeseed meal produced by solvent extraction is the form most commonly shipped in bulk at commercial scale. It is a high-protein feed ingredient (36% to 38% crude protein on a dry basis) used in compound feeds for poultry, pigs, cattle, and aquaculture. The meal has a distinctive, pungent smell from glucosinolate breakdown products, even though modern canola varieties carry dramatically lower glucosinolate levels than older high-glucosinolate rapeseed varieties.
Global production and trade volumes
Global rapeseed meal production reached 43.9 million tonnes in 2023 and an estimated 44.5 million tonnes in 2023/24, a record high. Canada is the largest producer, with canola crush capacity projected to reach 16 million tonnes annually by end-2025. The European Union, particularly Germany, France, and Poland, crushes significant volumes. Ukraine, Australia, and China are also material processors. Trade in rapeseed meal hit a new record in the 2024/25 marketing year, driven by Canadian and European expansion. China imported approximately 2.7 million tonnes of rapeseed meal in the marketing year ending September 2024, up from 2.03 million tonnes the prior year. The US, India, and South Africa together supplied 75% of total global rapeseed meal exports in the 12 months to February 2024 by shipment count.
Commercially sized bulk shipments move on Handysize (25,000 to 38,000 DWT) and Supramax/Ultramax (50,000 to 65,000 DWT) bulk carriers. Panamax vessels are used on longer deep-sea routes between crushing plants and major feed-compounding countries.
IMSBC Code schedule structure for seed cake cargoes
The IMSBC Code, adopted by IMO Resolution MSC.268(85) and in force since 1 January 2011, regulates rapeseed meal under the generic heading of seed cake. The Code does not publish a schedule specifically named “rapeseed meal”; instead, the shipper must determine which seed cake schedule matches the cargo’s measured oil and moisture content and declare the correct Bulk Cargo Shipping Name (BCSN), UN number, and IMDG class.
Amendment 05-19, which entered into force on 1 January 2021 after a voluntary-use period from 1 January 2020, restructured the seed cake section of the Code. The changes were material: the former single Seed cake (non-hazardous) Group C entry was deleted, the UN 1386 (b) schedule was revised, and two new schedules were created, one Group B (MHB) and one Group C, both carrying the new BCSN “Seed cakes and other residues of processed oily vegetables.”
The current framework, as it applies to rapeseed meal, comprises five distinct schedule entries:
The five seed cake schedules
| BCSN | UN Number | Extraction type | Oil content | Combined oil + moisture | IMSBC Group | IMDG Class |
|---|---|---|---|---|---|---|
| SEED CAKE, containing vegetable oil | UN 1386 (a) | Mechanically expelled | > 10% | or > 20% | B | 4.2 |
| SEED CAKE, containing vegetable oil | UN 1386 (b) | Solvent extracted or expelled | ≤ 10% | ≤ 20% when moisture > 10% | B | 4.2 |
| SEED CAKE | UN 2217 | Any | ≤ 1.5% | N/A | B | 4.2 |
| Seed cakes and other residues of processed oily vegetables (MHB) | None | Any | > 1.5% but ≤ 4% | ≤ 15% | B (MHB) | Not classified DG |
| Seed cakes and other residues of processed oily vegetables | None | Any | ≤ 4% | ≤ 15% | C | Not classified DG |
The table represents the structure as revised by Amendment 05-19. The UN 2217 schedule additionally requires the moisture content to be no more than 11%. The MHB Group B entry (row 4) applies to material that is not a classified dangerous good under IMDG but still presents a self-heating hazard and therefore falls within the IMSBC Code’s MHB (Materials Hazardous only in Bulk) framework under section 1.7.3 of the Code.
UN 1386 (a): Mechanically expelled, high-oil grade
UN 1386 (a) is the schedule that applies to rapeseed press cake from expeller operations where the oil content exceeds 10%, or where the combined oil and moisture content exceeds 20%. A cold-pressed expeller cake at 16% to 18% oil qualifies here. This is the highest self-heating risk grade. The IMSBC Code requires that the cargo shall be substantially free from flammable solvents and chemicals. It also requires the cargo to be “properly aged”: the duration of ageing varies with the oil content and must be declared by the shipper, because freshly processed expeller cake off-gasses heat rapidly and must stabilize before loading.
The loading temperature restriction is the same across all Group B seed cake schedules: cargo temperature at the time of loading shall not exceed the ambient temperature by more than 10°C, and in any case shall not exceed 55°C. UN 1386 (a) shall not be mechanically ventilated through-the-hold during the voyage (only surface ventilation is permitted); the reason is that drawing fresh air through a self-heating high-oil cargo body accelerates the oxidation reaction and can intensify rather than dissipate the heat.
UN 1386 (b): Solvent-extracted or combined, medium-oil grade
UN 1386 (b) applies to solvent-extracted or combined pre-press/solvent-extract rapeseed meal where the oil content is no more than 10%, and where the combined oil and moisture does not exceed 20% when moisture is above 10%. This is the schedule that covers most commercially produced rapeseed meal from large-scale industrial crush plants, where the final product is typically 1% to 3% residual oil at 10% to 12% moisture.
The revised UN 1386 (b) schedule introduced by Amendment 05-19 includes a downgrade exemption: solvent-extracted rapeseed meal, rapeseed pellets, soya bean meal, cottonseed meal, and sunflower seed meal containing no more than 4% oil and no more than 15% combined oil and moisture may be certified as non-self-heating and treated as the new Group C schedule if accompanied by a certificate issued by a person recognized by the competent authority. Without that certificate, the cargo stays in Group B under UN 1386 (b).
For voyages lasting more than five days, a vessel carrying UN 1386 (b) rapeseed meal must be fitted with gas injection equipment capable of introducing CO2 or inert gas into each hold.
UN 2217: Low-oil, low-moisture grade
UN 2217 applies when the cargo has no more than 1.5% oil and no more than 11% moisture. This schedule covers fully extracted, low-moisture rapeseed meal that has been brought below both the oil and moisture thresholds by thorough solvent extraction and appropriate drying. Commercially this is the form most often seen from large European and Canadian crush plants with modern post-extraction dryer-cooler circuits. Despite the low oil content, UN 2217 cargo is still IMDG Class 4.2 Group B because the residual oil is still sufficient to oxidize and deplete oxygen in the hold, and self-heating, while slower, can still occur.
For voyages more than five days, gas injection equipment is again required. The same temperature monitoring and entry precautions apply as for UN 1386.
MHB Group B: Certified low-oil, non-classified DG
The new MHB schedule for “Seed cakes and other residues of processed oily vegetables” (Group B) covers material that is not a classified dangerous good under IMDG but still poses a self-heating hazard detectable by the UN self-heating test in section 33.3 of the UN Manual of Tests and Criteria. This is the transitional classification for rapeseed meal at the boundary: more than 1.5% oil but no more than 4% oil, with combined oil and moisture no more than 15%, that passes the non-dangerous-goods threshold but still heats under test conditions. It does not carry a UN number but does require a Group B MHB declaration and the standard temperature monitoring and entry precautions.
Group C: Certified non-self-heating
The Group C schedule for “Seed cakes and other residues of processed oily vegetables” covers low-oil, low-moisture rapeseed meal that has been tested and certified as not meeting the MHB self-heating (SH) criteria per IMSBC Code section 9.2.3.3. The shipper must provide a certificate from a person recognized by the competent authority stating both that the product meets the exclusion thresholds for UN 1386 (b) or UN 2217, and that it does not meet the MHB (SH) criteria. Without that certificate, the Group C classification is not available and the cargo must be loaded as the highest applicable Group B schedule.
Group C seed cake does not require temperature monitoring or gas injection equipment. No DG transport document is required.
The MHB framework and rapeseed meal
The IMSBC Code defines Materials Hazardous only in Bulk in section 1.7.3. An MHB cargo is one that does not meet the IMDG Code classification criteria for dangerous goods when shipped in packaged form, but does present a hazard when carried in bulk quantity due to the aggregate quantity, the enclosed space, and the interaction of the cargo mass with its environment. Rapeseed meal fits this definition when it has been processed below the UN 1386 and UN 2217 oil and moisture thresholds but still retains sufficient reactive oil to self-heat under bulk conditions.
The MHB designation for seed cake was introduced precisely because practical experience with “non-hazardous” certified seed cakes showed self-heating events: bulk holds of material declared as Group C reached dangerous temperatures mid-voyage because the certification was either based on unrepresentative sampling or was deliberately falsified. The new MHB Group B schedule forces a more conservative classification on any cargo that has not been rigorously tested to the UN 33.3 protocol.
Self-heating mechanism in rapeseed meal
Self-heating in rapeseed meal proceeds through two linked processes, both driven by residual oil content and moisture.
The first is microbiological activity. At moisture contents above roughly 12%, fungal and bacterial populations in the cargo mass metabolize residual oil and protein. Metabolic heat is generated at low temperatures (typically below 70°C), raising the local temperature of the cargo.
The second is autoxidation of the residual vegetable oil. Rapeseed oil, like all vegetable oils, contains unsaturated fatty acids including oleic acid (C18:1), linoleic acid (C18:2), and linolenic acid (C18:3). These unsaturated bonds react with molecular oxygen in a chain reaction producing lipid peroxides and then short-chain aldehydes, ketones, and alcohols. This oxidation reaction is exothermic. At elevated temperatures it becomes self-accelerating: higher temperature increases the reaction rate, which produces more heat, which increases the temperature. The critical transition point is around 70°C to 80°C, above which the cargo body can reach ignition conditions without further external input.
Moisture interacts with both processes. It is necessary for microbiological activity. It can also retard the initial oxidation rate (water competes with oxygen at active sites) but accelerates secondary degradation reactions. The combined oil-plus-moisture threshold in the UN 1386 schedules (20% maximum for UN 1386 (b)) reflects the practical finding that high moisture and moderate oil together present greater risk than either individually.
Carbon monoxide is produced as a byproduct of the oxidation chain. CO concentrations in the hold headspace above a self-heating rapeseed meal cargo can reach dangerous levels (above the 50 ppm short-term exposure limit) well before any visible smoke appears. This makes CO monitoring the primary early-warning tool for detecting self-heating in progress.
The specific-gravity of rapeseed meal is approximately 1.1 to 1.25 t/m³. Bulk density (stowage weight) is approximately 0.6 to 0.72 t/m³, giving a stowage factor in the range 1.39 to 1.65 m³/t. The relatively low bulk density means holds fill by volume, creating larger air volumes at the top of the cargo and at stow boundaries where oxygen supply is sustained.
Carriage requirements under the IMSBC Code
Temperature monitoring
The IMSBC Code requires that the cargo temperature be measured regularly at a number of depths in each cargo space and recorded in the vessel’s log throughout the voyage. The Code does not specify a minimum frequency, but P&I club guidance recommends twice-daily measurements when loading high-risk grades (UN 1386 (a)) and at least daily for UN 1386 (b) and UN 2217 cargoes. Measurements are taken by inserting calibrated probes through sounding pipes or the hatch cover access trunking.
A temperature rise of more than 10°C above ambient across a 24-hour period warrants investigation and reporting to the owner, manager, and P&I correspondent. If the cargo temperature reaches 55°C and continues to increase, the master must notify the shipowner/manager and take action: ventilation to the cargo space shall be stopped. If self-heating continues after ventilation is closed, carbon dioxide or inert gas shall be introduced to the cargo space. CO2 smothers the oxidation reaction by displacing oxygen. The quantity required varies with hold volume and cargo type; the vessel’s CO2 fixed firefighting system may not be sufficient for a prolonged smothering operation, and carriage of supplemental CO2 in cylinders is sometimes specified.
If the temperature stabilizes and then decreases after CO2 injection, the hold should remain sealed until discharge. Reopening the hatch before the hold has cooled below 40°C and the atmosphere has been tested for oxygen and CO creates a condition for flashback: the heated cargo will rapidly re-oxidize when fresh air is admitted.
Ventilation
The ventilation rules differ between the schedule entries and constitute one of the more counterintuitive aspects of seed cake carriage:
UN 1386 (a): the cargo shall not be mechanically through-ventilated except in an emergency. Surface ventilation (air movement over the top of the cargo without drawing fresh air through the bulk from bottom to top) using natural cowl ventilators or low-volume mechanical fans is permitted. The reason for the through-ventilation prohibition is that driving fresh air into the base of a warm high-oil cargo mass delivers oxygen to the most reactive zone, accelerating self-heating rather than cooling it.
UN 1386 (b) and UN 2217: caution is required when mechanically ventilating. Surface ventilation should be conducted as necessary. If temperatures are rising, through-ventilation should be stopped; if they are stable or falling and the hold is cool, surface ventilation can continue. Opening and closing ventilators as conditions change is appropriate.
New Group B MHB: the same caution-applies approach as UN 1386 (b).
Group C: no specific ventilation restrictions; standard grain/general cargo ventilation practice applies.
Entry into cargo spaces: enclosed-space precautions
Hold spaces containing any grade of Group B seed cake must be treated as confined spaces and entered only after a risk assessment and gas testing confirms the atmosphere is safe. The IMSBC Code states that entry of personnel into cargo spaces loaded with seed cake shall not be permitted until tests have been carried out and it has been established that the oxygen content has been restored to a normal level and carbon monoxide is absent (or at a concentration at which it is safe to work).
An oxygen content below approximately 19.5% (the IMSBC Code typically requires restoration to near-normal atmospheric level) indicates that the cargo is still consuming oxygen. CO at concentrations above 50 ppm short-term exposure limit requires respiratory protection. Even when hatch covers have been open for an extended period, the access trunking and ladder well can remain oxygen-depleted or CO-enriched because warm gas stratifies and is not displaced by surface ventilation alone. Personnel entering should carry calibrated personal gas meters and wear appropriate respiratory protection if levels are borderline.
The entry procedure applies not only to during-voyage inspections but also to surveying at the port of discharge, stevedore access during discharge, and any hold work after partial discharge when pockets of cargo remain on the tank top or in the bilge system.
No ignition sources
The IMSBC Code prohibits smoking or the use of naked lights in, or adjacent to, any hold space containing Group B seed cake. The prohibition extends to the vicinity of cargo hold openings and ventilator intakes. This means no smoking on the hatch covers, no open-flame torches used for tank inspections, and no unprotected portable electric equipment taken into the hold during the voyage.
Loading temperature and pre-loading requirements
The 55°C (or ambient plus 10°C, whichever is lower) maximum cargo temperature at the time of loading is a hard limit applicable to all three Group B schedules. A loading master or surveyor attending the berth should take representative temperature readings from multiple positions in the shore stockpile or delivery conveyor. Cargo arriving above the threshold shall be rejected.
For UN 1386 (a) expeller cake, the Code additionally requires that the cargo be “properly aged” before shipment. The oil in freshly pressed expeller cake is reactive and the cake body temperature is elevated from the pressing process. The required ageing period varies with oil content: a 15% to 18% oil expeller cake may need several weeks of land storage to allow the fastest-reacting fraction of the oil to oxidize and the temperature to stabilize before the slow, lower-rate autoxidation characteristic of an aged cargo takes over.
Gas injection equipment
For voyages exceeding five days’ duration, vessels carrying UN 1386 (b) or UN 2217 rapeseed meal must be equipped with gas injection equipment capable of introducing CO2 or inert gas to each loaded cargo hold. This requirement was tightened by Amendment 05-19. The gas injection capacity requirement and the system design are specified in the Code; a ship’s fixed CO2 fire-suppression system may satisfy the requirement only if it has adequate capacity for the loaded holds and if the system design allows controlled injection rather than rapid total-flooding discharge.
Cargo certification and declaration
Shipper’s certificate
For UN 1386 and UN 2217 shipments, a certificate issued by a person recognized by the competent authority of the country of shipment must be provided to the master before loading. The certificate must specify the oil content and moisture content of the cargo. The competent authority in the country of shipment (typically the maritime administration, an approved laboratory, or a recognized testing body) sets the criteria for who can issue such certificates.
The certificate is not merely a declaration by the shipper; it must be based on representative cargo analysis. Representative sampling from the production batch or from the stockpile, using protocols that account for segregation and variability in the meal, is required. A single grab sample from the edge of the pile is not representative. P&I clubs have recorded cases where shippers deliberately obtained certificates based on low-oil samples while the main cargo body exceeded the threshold for the declared schedule.
Downgrade certificate for Group C
For a Group C classification under the new schedule, two conditions must be certified: (1) that the cargo meets the exclusion thresholds from UN 1386 (b) or UN 2217, and (2) that the cargo does not meet the MHB (SH) self-heating criteria under IMSBC Code section 9.2.3.3. The MHB (SH) test follows the UN Manual of Tests and Criteria section 33.3. The test is not trivial and requires specialized laboratory equipment; a routine moisture and oil analysis is not sufficient to demonstrate compliance with the MHB criterion.
Without both conditions certified, a shipper presenting a cargo as Group C is in violation of the IMSBC Code. The master’s obligation is to verify that the certificate is present and that its contents are consistent with the cargo offered for loading: if the temperature at loading is anomalously high, or the cargo smells strongly of recent oxidation or has a dark discoloration characteristic of hot-pressed expeller cake, the master should query the declaration and, if doubt remains, refuse the cargo or request independent testing.
IMO Form of cargo information (IMSBC Code Section 4)
Amendment 07-23, which entered into force on 1 January 2025 and incorporated the 2025 IMSBC Code edition, amended section 4.2.2 of the Code to require that the cargo information provided by the shipper include the bulk density of the cargo. For rapeseed meal, the typical bulk density declaration is 600 to 720 kg/m³ depending on moisture and processing method.
Self-heating incidents and misdeclaration
The single most documented operational risk in rapeseed meal and seed cake carriage is shipper misdeclaration. Documented incidents reviewed in P&I club and industry guidance include:
Cargo presented to a vessel as non-hazardous seed cake, with a certificate from the shipper stating it was outside the Group B thresholds, was found by an attending surveyor to be mechanically expelled rapeseed meal with oil content above the UN 1386 (b) limit. Laboratory analysis of the pre-loading sample confirmed the cargo conformed to UN 1386 (b) at best, not the Group C status declared. The attending surveyor formally objected; loading proceeded under the owner’s expressed objection, and the shipper certificate stated the cargo was non-hazardous. Temperature monitoring during the voyage showed consistent rise, and the cargo reached 55°C before the vessel reached its discharge port.
In other documented cases, allegedly non-hazardous seedcake reached temperatures as high as 80°C during the loading operation itself. The remedy in those instances was emergency discharge and replacement of the cargo. In one case, the shipper’s certificate was found to have used a sample taken from the outer surface of a cooled pile while the interior was still thermally active from the pressing operation, which is a sampling protocol violation.
The lesson from these incidents is that a shipper’s certificate is a necessary but not sufficient safeguard. The master and the owner’s surveyor must assess the cargo physically: odour (strong, pungent, or rancid beyond the characteristic glucosinolate smell of rapeseed), colour (dark brown or black discoloration suggests oxidized oil), and loading temperature are all observable indicators that should be checked against the declared schedule.
Carbon monoxide monitoring during loading, not only during the voyage, is sound practice for any high-oil seed cake cargo. CO build-up is detectable in the hold headspace before visible heating signs appear. A CO concentration above 200 ppm in the hold at loading is a strong indicator of active self-heating.
Voyage monitoring procedure and emergency response
A well-run rapeseed meal voyage follows a structured monitoring cycle. Before departure, the master should confirm that pre-loading temperatures were recorded, the shipper’s certificate is filed with the cargo documents, gas injection equipment is tested and ready, and a baseline CO reading has been taken from each loaded hold with the hatch closed.
During the sea passage, temperature readings at a minimum of three depths per hold (top, mid, and bottom of the cargo stow) should be taken and logged at least once per day. Some owners specify twice daily for UN 1386 (a) cargo because the induction period for high-oil expeller cake can be short. The absolute temperature matters less than the trend: a cargo that stabilizes at 45°C and stays there is less concerning than one rising from 30°C to 40°C to 50°C over successive days.
CO monitoring complements temperature monitoring. CO is produced at low concentrations during normal slow oxidation and at escalating concentrations as self-heating accelerates. Industry guidance (from classification societies and P&I clubs) typically treats a CO level above 50 ppm in the hold headspace as requiring increased monitoring frequency, above 100 ppm as requiring master and owner notification, and above 200 ppm as requiring the commencement of emergency procedures regardless of measured cargo temperature. CO can reach dangerous concentrations in the hold access trunking even when the main hatch covers remain closed, because the gas seeps upward through the cargo and accumulates in any connected air pocket.
The emergency sequence, as specified in the IMSBC Code schedule for Group B seed cake, proceeds in steps. First, close all ventilators serving the affected hold. Second, if the temperature stabilizes within a few hours of ventilator closure, maintain the closed condition and monitor. Third, if the temperature continues to rise despite closed ventilation, introduce CO2 or inert gas to the hold. The injection rate and volume are not specified by the Code; the objective is to reduce the oxygen content in the hold headspace to below approximately 5%, at which point the oxidation chain cannot sustain itself. The vessel’s crew should consult the gas injection system manufacturer’s guidance and the cargo’s safety data sheet for the applicable quantity.
After CO2 injection, the hold must remain sealed during the passage and at berth until discharge begins and the hold atmosphere is retested. Under no circumstances should the hold be opened for inspection mid-voyage after a CO2 injection unless crew wear self-contained breathing apparatus (SCBA) rated for the expected atmosphere. A hold charged with CO2 at suppression concentration (10% to 20% CO2 by volume) is immediately fatal upon entry without SCBA.
Discharge operations require an enclosed-space entry procedure. Before stevedores and crew enter the hold for rigging grabs or opening cargo access hatches at the base of the trunking, the atmosphere must be tested for oxygen content, CO, and CO2 by a competent person with calibrated instruments. The testing authority should document the result. If oxygen is below 19.5% or CO is above the short-term exposure limit, entry is prohibited until the hold has been force-ventilated to restore a safe atmosphere.
Port state control and port authority considerations
Port state control (PSC) officers boarding a vessel carrying Group B seed cake have authority under SOLAS Chapter VII (which incorporates the IMSBC Code by reference) to verify:
- That the shipper’s certificate is present and complies with the Code
- That the declared BCSN, UN number, and IMDG class are consistent with the certificate’s oil and moisture values
- That the vessel has the required gas injection equipment fitted and operational for voyages over five days
- That temperature monitoring records are being maintained
- That the cargo was not loaded above the temperature limit
Deficiencies in any of these areas can lead to detention or condition of class action. The IMSBC Code is a mandatory instrument under SOLAS; non-compliance is not an administrative matter.
At loading ports, harbour masters in some jurisdictions require pre-loading notification for Group B DG cargoes. The IMDG Supplement (EmS guide) applies to seed cake UN 1386 and UN 2217 and specifies segregation from flammable and oxidizing materials in adjacent holds or on deck. The specific EmS schedule for UN 1386 should be verified against the current edition of the IMDG Code’s EmS guide.
Hold preparation and stowage
Rapeseed meal generates fine, dusty particles that penetrate bilge systems and lodge in pipe joints. A thorough hold cleaning prior to loading, to a grain-clean standard, is appropriate because the previous cargo’s residue can contaminate the rapeseed meal and complicate the receiver’s quality assessment. The bilge system should be checked clear and free to drain.
Rapeseed meal has an angle of repose of approximately 30° to 35°. It does not liquefy (it is not Group A) and does not shift at normal angles of list, but full and properly trimmed holds are standard practice. The stowage factor of 1.39 to 1.65 m³/t means that a Supramax with five holds totaling approximately 65,000 m³ grain capacity can load roughly 40,000 to 47,000 tonnes of rapeseed meal at typical density.
Adjacent hold stowage should avoid materials that are strong oxidizers or strong acids, as these would accelerate the autoxidation reaction if cross-contamination occurred through bilge or ventilation systems. Rapeseed meal has a strong, persistent odour from glucosinolates and their breakdown products; it taints subsequent cargoes if residue remains in the hold. A grain-clean wash-down and inspection before the next cargo is standard practice.
Rapeseed versus canola: the naming distinction at sea
“Rapeseed meal” and “canola meal” are used interchangeably in commercial shipping documentation, but they refer to the same product for IMSBC Code purposes. The IMSBC Code does not maintain a separate entry for canola; the seed cake schedules apply regardless of whether the source crop is traditional high-erucic rapeseed (still grown for industrial oil) or modern low-erucic canola varieties. The nutritional profile differs between the two (lower glucosinolates and erucic acid in canola meal), but the physical hazard properties driving the IMSBC schedule depend on oil content and moisture, not on the cultivar. Shippers in Canada and Australia consistently use “canola meal” in trade documentation, while European and Indian exporters use “rapeseed meal,” but the cargo safety declaration must reference the applicable IMSBC BCSN regardless of the trade name used in the bill of lading.
Related calculators
The companion calculator for rapeseed meal stowage planning is IMSBC Rapeseed Meal, which returns hold volume, cargo mass, and bulk density reference data for the declared cargo. For rapeseed pellets, which are a compacted form of the meal with slightly different bulk density and stowage properties, see IMSBC Rapeseed Pellets. The general IMSBC Group A/B/C classifier can be used to cross-check the applicable schedule against declared oil and moisture values.
For the non-hazardous Group C grade, IMSBC Seed Cake (Non-Hazardous) provides reference data. Related oilseed meal calculators include IMSBC Soya Meal, IMSBC Cottonseed Meal, and IMSBC Sunflower Seed Meal.
Limitations
This article is a reference guide based on the IMSBC Code text as amended through Amendment 07-23 (2025 edition) and on P&I club and classification-society guidance published through 2024. It does not substitute for the current official text of the IMSBC Code, which should be consulted directly from an IMO-authorized source. The schedule thresholds for oil and moisture content are drawn from the Code; however, the precise testing methods for measuring residual oil in seed cake, and the protocols for demonstrating MHB (SH) compliance, require laboratory expertise and should not be substituted by field estimation.
Amendment 08-25, with voluntary use from 1 January 2026 and mandatory force from 1 January 2027, may modify the seed cake provisions. Masters and shipowners must verify the applicable edition of the Code before accepting a cargo declaration.
The self-heating temperature thresholds cited here (55°C intervention, CO2 injection trigger) are from the Code’s schedules as of Amendment 07-23. National competent authorities may impose more conservative requirements on Flag State-registered vessels. P&I club cover may be conditional on compliance with voyage-specific additional measures beyond the Code minimum.
The incident descriptions in this article are drawn from published P&I club guidance and industry safety documents and represent categories of events documented in the industry, not fabricated scenarios. Specific vessel names and dates are not cited because the original published guidance documents present them anonymously to encourage reporting without liability disclosure concerns.
See also
- IMSBC Code: the framework that governs all solid bulk cargoes
- IMSBC Group B Cargoes: chemical-hazard Group B classification framework
- IMSBC Group C Cargoes: non-hazardous Group C cargoes
- Fishmeal: IMSBC Code Schedule and Carriage: another Group B self-heating organic bulk cargo
- Soya Beans: IMSBC Code and International Grain Code Carriage: soya beans and soya meal trade
- Bulk Carrier: vessel type used for rapeseed meal shipments