Marine fuel oil bunkering procedure

Legal framework and considerations

Fuel oil supply for use on board seagoing vessels must legally comply with MSC-MEPC.2/Circ.18: IMO Guidelines for the sampling of fuel oil for determination of compliance with MARPOL VI and SOLAS II-2. These guidelines are included in MARPOL VI/18.8.1 and implemented into Dutch law per Article 3.3 of the Besluit brandstoffen luchtverontreiniging (fuels air pollution Decree, in Dutch). The ILT checks supplied fuel oil for compliance with:

• Sulphur content requirements set out in MARPOL VI/14.
• Quality requirements set out in MARPOL VI/18.3.
• Flashpoint requirements set out in SOLAS II-2/4.

Before bunkering, you must provide the person responsible for bunkering on the seagoing vessel with a veiligheidsinformatieblad, VIB (safety data sheet, SDS) for each type of fuel oil in the supply.

In addition to legal requirements, the ILT recommends, but cannot enforce, following ISO 13739 in bunker procedures. ISO 13739 may help avoid discussions and confusion. Preferably, the fuel oil delivery agreement should include conditions for returning the fuel oil if the recipient does not accept the delivery.

It is important that all parties involved agree on the correct application of the bunkering procedure, in order to ensure mutual trust and resolve issues and problems within the bounds of the legal requirements.

Fuel oil sampling during bunkering

You must have a representative sample of the fuel oil taken during bunkering. This enables checking that all supplied fuel oil meets the specifications in the bunker delivery note (BDN), in accordance with legal requirements.

Attendees

Sampling requires the joint presence of:

• Your (the supplier’s) representative.
• A representative of the receiving vessel. This can be the ship master or chief engineer.

Both parties must check the sampling procedure and, if needed, ask for changes. This includes details such as flushing the sampling device, adjusting the sampling rate, or marking the containers.

Both parties may appoint a surveyor. This is good practice but not required. If appointed, the surveyor or surveyors must be present during sampling.

The ILT will not allow you to deviate from the sampling requirements only because you think it is unsafe to board the receiving vessel. You may only deviate from the requirements in the following situations:

• Your representative is not allowed to board the receiving vessel.
• It is impossible to carry out sampling on board the receiving vessel as required.

In these cases, you must acquire a signed statement from the receiving vessel and immediately inform the ILT. Use this statement as proof. This allows the ILT to decide whether to attend the sampling. However, ILT attendance is not required for sampling.

Sampling point

You must have the primary sample collected at the bunker inlet manifold on board the receiving vessel. This sampling point must allow for inspection and cleaning before and during bunkering.

Samples taken for any reason at other points, including on board the bunker barge, do not meet the legal requirements for representative samples. These samples must not be marked as representative on the BDN.

Sampling equipment

The sampling equipment at the sampling point must either be pre-installed, or be part of a flange that is inserted between the inlet and the hose flanges.

The sampling equipment must have a tube across the full width of the pipe, with openings facing the flow direction (as pictured in ISO 13739, informative Annex M), using 1 of the following devices:

• Manual valve-setting continuous-drip sampler. It is recommended to use a needle valve to keep a steady drip flow.
• Time-proportional automatic sampler.
• Flow-proportional automatic sampler.

If there is no sampling equipment on board the receiving vessel, you must provide it.

The sampling equipment must be in place, clean and ready to use before bunkering starts.

Collecting the primary sample

You must have the primary sample collected:

• Over the full course of the bunkering process.
• In a large single container, large enough to hold all the required sub-samples.
  For 4 sub-samples, use a 5-litre cubitainer. If you need more sub-samples, use a 10-litre cubitainer.

Drawing and sealing the sub-samples

You must have at least 3 sub-samples drawn:

• 1 for you as the supplying party.
• 1 for the procuring party.
• 1 to remain on the receiving vessel.

This allows for counter-analysis if there is a dispute. The parties may agree to take more sub-samples. The ILT may also request a sample.

You must have each sub-sample drawn:

• From the primary sample container.
• After the sample has been properly mixed (homogenisation by agitation).
• Into a sub-sample container that:

• Holds at least 600 ml, preferably 750 ml.
• Can be sealed and countersealed, for example by matching holes in the cap and container rim.
• Is sealed and, if agreed, signed and countersealed by both parties after filling.

Seals are required by law. Counterseals and signatures are not required by law. You must write down the numbers of all seals, and if agreed, all counterseals, in the correct spaces on the BDN.

Analysing the sample

Taking samples is required by law, but analysing them is not. Analysis can help prevent issues with fuel oil quality during use.

Keeping the sub-samples

The vessel must keep its sub-sample until all of the fuel oil has been used, and at least for 12 months after supply.

The other parties should also keep their sub-samples for 12 months. This allows for counter-analyses in case of issues, for settling business disputes, or for checking if fuel oil that does not match the BDN was supplied. If no counter-analyses take place, the available sub-samples are leading.

Bunker delivery note (BDN)

You must have the BDN drawn up after bunkering. The BDN enables the ILT to check if the fuel oil complies with the specified standards.

Required BDN contents

MARPOL VI Appendix V specifies which information must be included in the BDN. The BDN must include at least:

• The product name, including the corresponding ISO-F fuel-grade code as specified in ISO 8216-1, to indicate the specific fuel oil type and quality.
• The product specification, including the ISO 8217 version the fuel oil should comply with. If no ISO 8217 version is mentioned, the ILT will use the latest version of ISO 8217:2024 to check compliance.
• Details of the differences with ISO 8217 and their agreed alternative limits. This is required if the fuel oil does not fully comply with ISO 8217.)
• The percentage of FAME added, if this percentage is higher than 0.5% and the fuel oil should comply with a pre-2024 ISO 8217 version.
• The quantity of fuel oil supplied in metric tonnes at the end of the bunkering procedure, including how it was measured.
• The density of the fuel oil at 15°C (kg/m³).
• The sulphur content of the fuel oil (percentage by mass, reported to 2 decimal places).
• Any extra analytical data from the sample, if available.
• Seal and counterseal numbers of all legally required sub-samples. It is not allowed to include seal or counterseal numbers of other samples on the BDN.
• Your contact details, including email address for communication on supply and bunkering.
• If your trade name differs from the business name registered with the respective Chamber of Commerce, you will need to provide your business registration number.
• Name and IMO number of the receiving vessel.
• The date of fuel oil supply.
• The location of fuel oil supply (port).
• A signed statement in which you confirm that the fuel oil complies with MARPOLVI Regulations 14 and 18.3 and that all supply details are correct. The chief engineer or ship master must sign or stamp this declaration as proof of receipt.

As of 1 January 2026, the BDN must also include information on renewable fuels, such as the quantity, type, and source. From that date, the Besluit brandstoffen luchtverontreiniging (Fuels Air Pollution Decree) will implement the EU Renewable Energy Directive III and the FuelEU maritime regulation.

The port authority may also require extra information on the BDN, for example in the bunkering permit.

Optional BDN contents

ISO 13739 lists extra information that can be added to the BDN as good practice:

• Total duration of bunkering, or the end date and time.
• Name and ENI number of the bunker barge supplying the fuel oil.
• Details of how the fuel oil sample was taken.
• Stamp and signature of the surveyor or surveyors, if present.
• A unique number you use to identify specific supplies.

Ship master’s Letter of Protest (LoP) in case of irregularities

If there are any irregularities or cases of non-compliance with the above requirements, the ship master must report them immediately using a Letter of Protest (LoP). The ship master must send the LoP to your representative, who must countersign to confirm receipt. The ship master must send copies of the countersigned LoP to the ship’s flag state administration and the ILT as the port state authority.

You must review your operations based on each LoP.

Based on LoPs, the ILT may start investigations into fuel oil suppliers or bunker barge operations, notifying the parties involved. In case of non-compliance, the ILT will inform the IMO of the results of the investigation in GISIS.