INTRODUCTION
Fuel supply in maritime trade is an essential service for a vessel to continue its voyage, yet it is one of the areas most frequently giving rise to disputes in practice. Claims that fuel does not meet quality criteria can lead to operational failures, delays, and additional costs on board, as well as raising questions about which party is liable and what evidence is required to prove liability.
This article will evaluate the most common types of bunker disputes in Türkiye and internationally, as well as the impact of contract drafting and evidence management on the outcome of the dispute. Furthermore, the practical implications of the reference to the ISO 8217:2017 standard and the role of dispute resolution methods, including arbitration, in such disputes will be evaluated within an application-oriented framework.
A. TYPICAL APPEARANCE OF BUNKER DISPUTES AND THE FUNCTION OF ISO 8217:2017
Bunker disputes are primarily grouped under two headings in practice: (i) claims of underdelivery of fuel quantity and (ii) claims of unsuitability (“off-spec”) of fuel quality. In quantity disputes, inconsistencies between the measurement method and the records on which the measurement is based (measurement data, barge measurements, ship tank measurements, and delivery documents) are decisive. Quality disputes, on the other hand, are mostly shaped by claims that the delivered fuel caused malfunction, loss of performance, filtration problems, or unexpected maintenance and cleanup needs during its use on the vessel. In both types of disputes, the decisive factor is the scope of the parties’ contractual obligations as defined by technical criteria and the evidentiary framework in which the claims are presented.
One of the most common technical references in quality discussions is the ISO 8217:2017 standard. ISO 8217 is a standard published by the International Organization for Standardization (“ISO”) concerning the classification of marine fuels and the determination of minimum technical criteria for specific parameters. In practice, reference to ISO 8217 creates a common technical language and benchmark for the parties in the “conformity” assessment, but it does not establish a liability regime on its own. In other words, ISO 8217 does not constitute a regulation that automatically gives rise to liability for damages or determines fault; rather, it functions as a reference framework that concretizes the technical content of the quality commitment agreed upon in the contract.
Therefore, the practical effect of ISO 8217 should often be evaluated in conjunction with the structure of the contract. Unless the parties go beyond merely referring to ISO 8217 in the contract and clearly regulate the scope of the reference and the method of application (e.g., the fuel class/grade to be delivered, the test methods to be applied, which sample will be used as a basis, notification and objection periods and procedures), the claim of “compliance with ISO 8217 conformity” claim may not be sufficient on its own for resolving the dispute. This is because in bunker disputes, the debate often focuses on determining the sample used for analysis, the representativeness of the sample, and the reliability of the chain of custody for the sample, rather than the laboratory result itself. Therefore, while ISO 8217 establishes the technical framework, the key factor determining the legal course of the dispute is how this framework is implemented in the contractual process and evidence management.
B. EVIDENCE PROCESS IN BUNKER DISPUTES
In bunker disputes, the burden of proof largely rests on technical records created at the time of delivery and verifiable later. Therefore, in order to successfully assert or refute a claim of “unsuitable fuel” it is crucial that the delivery process is documented in accordance with the procedure and that the evidence is preserved. In practice, a significant portion of disputes are locked in on the issue of which sample and which report should be used to assess suitability, rather than whether the fuel is suitable.
In this context, the first critical point is the sampling process. How the sample is taken, how it is preserved, whether sealing/labeling procedures are performed, and whether the sample is delivered between the parties directly affects the reliability of subsequent analyses. Particularly in the event of a dispute, failure to clearly define the sample to be accepted as the “reference sample” in the contract may lead to the parties relying on different samples and conflicting laboratory results. Therefore, the representativeness of the sample and the establishment of an unbroken chain of custody for the sample are important in proving the claim and overcoming the other party’s objections.
A secondary point is the Bunker Delivery Note (“BDN”), which is the primary document for delivery, and the accompanying delivery documents. The BDN is the main reference document in practice for recording elements such as the type/grade of fuel, quantity, place, and time of delivery. However, it should be noted that the BDN alone does not create a conclusive presumption of “conformity.” In particular, quality objections are often based on sample analyses and operational findings on board the vessel, independent of the data contained in the BDN. Therefore, it is important to evaluate the BDN together with measurement records, meter outputs, barge/vessel measurement reports, minutes taken during delivery, and survey reports, if any, in order to manage the dispute in a proper manner.
The third point is the laboratory analysis and reporting process. Laboratory reports serve as the basis for the “conformity” assessment in terms of the parameters specified in ISO 8217. However, the report’s evidential value is directly affected by which sample the report relates to, what the analysis method is, and which tolerance approach will be used to evaluate the report. In practice, if the parties use different laboratories or have analyses performed on different samples, multiple and conflicting reports may arise for the same delivery. This situation shifts the basis of the dispute from a technical discussion to a discussion of evidence, ultimately bringing to the fore whether the procedures stipulated in the contract have been followed and the reliability of the evidence.
Therefore, in bunker disputes, it is essential to conduct rapid and disciplined evidence management from the moment of delivery. The key factors determining the course of the dispute are the complete implementation of the sampling and sealing process during delivery, the consistent preservation of BDN and measurement records, the timely submission of written reservations in the event of a possible objection, and the preservation of samples in a manner ready for the analysis process. Indeed, in practice, it has been observed that claims that could be considered justified due to deficiencies in sample and document management, regardless of technical parameters, cannot be proven; conversely, claims supported by a strong set of evidence can be resolved much more quickly and predictably.
C. RESOLUTION OF BUNKER DISPUTES
As explained in detail above, reference to ISO 8217:2017 in bunker disputes should not be considered a protective provision in itself. What is decisive in practice is whether the reference to ISO 8217 is supported by a contractual procedure. In this context, clearly specifying the class of fuel to be delivered in the contract, clarifying matters such as where and how the sample will be taken, which sample will be accepted as a reference, the number of samples, and storage conditions, as well as regulating which laboratory and which test methods will be used for analysis in the event of a dispute and who will cover the analysis costs, makes the “conformity” discussion manageable. Similarly, clearly defining objection and notification periods, determining how reserve records will be communicated, and deciding what information and documents will support an objection prevents procedural objections that may arise later.
On the other hand, considering that fuel supply often involves multiple contractual relationships, disputes may also diverge in terms of the parties involved and who is liable. Therefore, establishing a clear framework in the contract regarding representation, the party responsible for payment, to whom delivery is made, and the chain of recourse will be of critical importance, especially in scenarios where quality claims are directed at different parties based on the results arising on board the vessel.
In terms of dispute resolution, arbitration clauses are frequently found in contracts. Indeed, arbitration options are provided for dispute resolution in standard bunker terms widely used in international practice (e.g., BIMCO Bunker Terms), and arbitration is often included in the contract as the default resolution method. Arbitration may be preferred by the parties due to the evaluation of technical evidence and specialized application experience; furthermore, elements such as confidentiality and procedural flexibility may contribute to the management of the dispute. However, the selection of arbitration does not diminish the importance of evidence and procedural management. On the contrary, in arbitration proceedings, the factors that influence the outcome are the samples, BDN, and measurement records created from the moment of delivery and whether they are operated in accordance with the procedure stipulated in the contract. Therefore, regardless of the dispute resolution method, the predictable design of the contract structure and evidence set from the outset constitutes the fundamental element of effective risk management in bunker disputes.
D. CONCLUSION
The ISO 8217:2017 standard is of central importance in establishing the technical basis for the “conformity” assessment in bunker disputes. Indeed, quality claims are often substantiated based on the parameters set out in ISO 8217, and the proof of the dispute is shaped by the samples taken at the time of delivery and the related laboratory analyses. Therefore, the reference to ISO 8217 creates a common technical language between the parties in practice and determines the criteria on which the dispute will be discussed. However, it should not be overlooked that the standard does not establish a liability regime on its own; the legal consequences depend on how the reference to ISO 8217 is structured in the contract, together with elements such as sampling, analysis method, notification, and objection periods.
Furthermore, arbitration often emerges as the primary resolution platform in bunker disputes in international practice. The fundamental reason for this is that these disputes involve dimensions requiring expertise, such as technical evidence assessment, multi-party supply chains, and the implementation of contractual procedures. In this context, effective risk management is possible through the proper integration of ISO 8217 into the contractual structure and the establishment of a complete set of evidence, consisting of samples, BDN, measurement records, and analysis reports, from the moment of delivery, in a manner that can be presented in a potential arbitration proceeding. When this approach is adopted, it will be possible to both reduce risks and resolve disputes arising from bunker disagreements in a more predictable and effective manner.
