LR warns compliant marine fuels can still cause onboard problems

Lloyd’s Register says ship operators are facing a rising risk from marine fuels that pass routine ISO 8217 checks but still trigger operational issues after bunkering. The H1 2026 FOBAS report points to unstable blends, elevated shale oil content and recurring off-spec problems as fuel complexity grows.

Why it matters: - Ship operators can no longer rely only on pass-or-fail ISO 8217 testing to judge fuel risk. - Fuels that appear compliant can still disrupt filters, separators and fuel pumps once onboard. - The shift raises the risk of vessel downtime, maintenance issues and performance losses across the marine fuel supply chain.

What happened: - Lloyd’s Register said its latest Fuel Oil Bunker Analysis and Advisory Service report found growing operational problems with fuels that meet routine compliance limits. - The report covers the first half of 2026 and focuses on marine fuel quality trends seen by FOBAS. - In March and April, several vessels reported problems after bunkering fuel at a major bunkering hub. - Forensic analysis found elevated concentrations of Estonian shale oil in some of those fuels, with levels estimated at around 10% to 15% in some cases.

The details: - Off-specification fuels remained a persistent issue in H1 2026. - Some of the most disruptive cases involved fuels that passed routine testing but later showed poor stability, poor compatibility or non-conventional blend components. - Shale oil is recognized under ISO 8217 as an acceptable blend component. - FOBAS found that higher shale oil concentrations can be linked to fuel instability and operational problems. - The report said recurring issues included sulphur exceedances, excessive water content, sediment and stability problems, elevated catalytic fines, sodium contamination and low flash point distillate fuels. - Fuel quality variability stayed elevated through the first six months of 2026. - FOBAS said that suggests fuel quality problems are now a persistent feature of the marine fuel supply chain, not isolated events. - Biofuels, especially FAME blends, continued to grow without becoming a primary source of quality problems. - Where issues did appear in blended fuels, they were generally tied to the conventional VLSFO component rather than the FAME fraction. - Murray Kirkwood, Fuel Specialist Consultant at Lloyd’s Register, said the main challenge is no longer just identifying off-spec fuel. - Kirkwood said operators are increasingly dealing with fuels that meet required limits but still create operational difficulties after storage, handling and use onboard. - Kirkwood said the key distinction is shifting toward operationally resilient fuel versus operationally fragile fuel.

Between the lines: - The report points to a deeper problem in marine fuels: compliance alone may not reveal how a fuel will behave in real operating conditions. - As blending gets more complex, detailed composition analysis becomes more important for spotting risks early. - FOBAS is framing fuel management as a behavior and stability issue, not just a specification check.

What's next: - Shipowners and operators are likely to lean more heavily on proactive fuel management practices. - Greater focus on stability, compatibility and fuel composition will be needed to limit disruption. - FOBAS said combining routine monitoring with forensic analysis can help operators identify emerging fuel risks more effectively. - The FOBAS Fuel Insight: Fuel quality reports are available in LR’s FOBAS Fuel Insight report hub.