The shipping industry is facing a growing challenge as it transitions to a more complex fuel landscape. According to Lloyd's Register (LR), ship operators are encountering fuels that appear compliant under routine ISO 8217 testing but still present operational risks once onboard. This is a significant shift from the past, where the primary concern was identifying fuels that failed specification. Now, the focus has shifted to understanding the behavior of fuels that meet the required limits but still cause operational difficulties.
The Fuel Oil Bunker Analysis and Advisory Service (FOBAS) Fuel Quality Report for the first half of 2026 highlights a persistent issue with off-specification fuels. However, a concerning trend is emerging: some fuels that pass routine compliance testing show poor stability, compatibility, or contain non-conventional blend components that are only identified through more detailed investigative analysis.
Several incidents investigated by FOBAS illustrate this trend. In March and April, multiple vessels reported operational difficulties after bunkering fuel in a major hub. Forensic analysis revealed that many of the fuels contained elevated concentrations of Estonian shale oil, estimated at around 10-15%. While shale oil is recognized within ISO 8217 as an acceptable blend component, higher concentrations can lead to fuel instability and operational issues affecting filters, separators, and fuel pumps.
The report also underscores the ongoing challenge of fuel quality variability. Off-specification cases remained elevated throughout the first six months of 2026, suggesting that quality issues are no longer isolated events but a persistent feature of the marine fuel supply chain. The most common recurring issues included sulfur exceedances, excessive water content, sediment and stability problems, elevated catalytic fines, sodium contamination, and low flash point distillate fuels.
Interestingly, biofuels, especially FAME blends, are not the primary source of quality issues. When issues occurred in blended fuels, they were generally associated with the conventional VLSFO component rather than the FAME fraction. This finding highlights the importance of understanding the composition of fuels and their potential interactions.
The report emphasizes the need for ship operators to adopt a more proactive approach to fuel management. As marine fuels become more diverse and fuel quality risks harder to identify through routine compliance testing alone, operators must focus on fuel stability, compatibility, and understanding fuel composition. This will be critical to reducing operational disruption and maintaining vessel performance.
Murray Kirkwood, Fuel Specialist Consultant at Lloyd's Register, underscores the evolving nature of fuel quality risk. He states, 'The challenge is no longer simply identifying fuels that fail specification. Increasingly, operators are encountering fuels that meet the required limits but still create operational difficulties once stored, handled, and used onboard. As fuel blending becomes more complex, the distinction between operationally resilient and operationally fragile fuels is essential for shipowners and operators.'
FOBAS' long-standing view is that effective fuel management depends on understanding fuel behavior rather than relying solely on pass-or-fail specification testing. By combining routine fuel quality monitoring with forensic investigation of operational incidents, FOBAS provides shipowners with a clearer understanding of emerging fuel quality risks. This approach is crucial as the industry navigates the complexities of a more diverse and complex fuel landscape.
In conclusion, the shipping industry must adapt to the evolving challenges of fuel quality. While routine compliance testing remains important, a deeper understanding of fuel behavior and composition is essential to ensure operational resilience. As the industry transitions to a more complex fuel landscape, the distinction between operationally resilient and fragile fuels will be a critical factor in maintaining the performance and safety of vessels.
