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Bunker Fuel Quality

Gard offers recommendations to mitigate risk of catfines in marine fuel

Following reports by members and clients indicating a significant increase in catfines in both VLSFO and HSFO in major bunkering ports during August 2025, the P&I club outlines its recommendations.

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Following reports by Gard members and clients indicating a significant increase in catfines in both Very Low Sulphur Fuel Oil and High Sulphur Fuel Oil in major bunkering ports during August 2025, maritime protection and indemnity (P&I) club Gard offered key recommendations in this article, published on 9 September, to mitigate risk of catfines in marine fuel:

We refer to Veritas Petroleum Services’ (VPS) Circular ‘A Global Pandemic of High Catfines in Marine Fuel’ dated 4 September 2025. Between 11 August and 31 August 2025, VPS observed a high number of elevated catfine levels, ranging from 62-176 ppm, in fuel across the regions shown in the below illustration. This is a trend that mirrors Gard’s own experience.

Gard offers recommendations to mitigate risk of catfines in marine fuel

Understanding catfines

Catfines are microscopic, abrasive particles that pose a significant threat to a vessel’s engine. Short for catalytic fines, these particles are composed mainly of aluminum (Al) and silicon (Si). Along with viscosity and water, catfines are considered one of the three most critical properties to monitor in fuel quality at the engine inlet. To put their size into perspective, catfine particles range from 1 to 75 microns. A micron, or micrometer, is just 0.001 millimeters. In comparison, a human hair is about 50 to 70 microns thick, and a fine grain of sand is around 90 microns. Larger particles are more abrasive and can cause severe wear and damage to critical engine components such as cylinder liners, piston rings, and fuel injectors.

Catfines are extremely hard and abrasive. They can scratch or become embedded in the steel surfaces of marine engine components, particularly those that move against each other. When they enter an engine, they can lead to high wear rates and scuffing, resulting in costly damage to key parts. Factors like a vessel’s motion in rough seas can stir up previously settled material in fuel tanks.

Catfines in VLSFO

The problem with cat fines is compounded in VLSFO due to several factors. The fuel’s typically low viscosity can reduce the effectiveness of centrifugal separators, while its varied composition makes its behaviour unpredictable. If the fuel is not sufficiently heated, waxes can precipitate and clog purifiers and filters, further diminishing their ability to remove these abrasive particles. Adding to the complexity is the risk of re-dissolving cat fines from old tank sediments. Given these challenges, rigorous fuel management is critical.

Industry standards

The ISO 8217 standard sets a maximum limit for catfine levels in fuel. The 2010, 2012, 2017, and 2024 versions set a maximum limit of 60 mg/kg (or 60 ppm) for viscous fuel grades as delivered to the ship. This limit is a significant reduction from the 80 mg/kg limit listed in the 2005 standard. It is crucial to note that the ISO 8217 limit applies to the fuel as it is delivered, not as it enters the engine. 

For safe operation, most engine manufacturers recommend that catfine levels at the engine inlet be much lower — ideally below 15 ppm. To meet these requirements, vessels must rely on effective onboard fuel treatment systems. An overview of some of the major OEM requirements for fuel quality before the engine and for fuel cleaning systems can be found in Appendix I of CIMAC Guideline Design and operation of fuel cleaning systems for diesel engines (09, 2024 v2).

Key recommendations

Effective management of cat fines is crucial to prevent engine damage. While most owners and managers have established procedures, we reiterate some of the most important practices to mitigate the risk. 

Bunkering & Sampling

  • Source fuel carefully – Prioritize reputable suppliers when bunkering and avoid less-known local providers.
  • Define clear specifications – Ensure charter parties include detailed fuel specifications, latest ISO 8217 standard, recommended suppliers, and precise handling and sampling requirements.
  • Follow standard procedures – Adhere to industry-standard sampling practices, including taking samples from the ship’s manifold, using proper cubitainers, and ensuring all documentation (such as the Bunker Delivery Note) is correctly completed.
  • Analyze before use – Conduct a thorough sample analysis before using the new fuel.

Onboard Storage & Settling

  • Increase segregation – Maintain increased bunker segregation to avoid contamination.
  • Test for compatibility – If mixing is unavoidable, conduct compatibility testing and follow specified mixing ratios.
  • Allow for settling – Ensure the fuel has appropriate settling time in the tanks.
  • Drain tanks – Settling and service tanks should be drained a minimum of twice daily.
  • Clean tanks – Clean settling and service tanks whenever possible to remove sediment.

Purification

  • Choose the right purifier disc based on the fuel’s density.
  • Operate at the correct temperature as recommended by the fuel analysis report.
  • Consider using both purifiers (in parallel or in series) at appropriate feed rates to increase efficiency.
  • Maintain purification units with proper care and maintenance.

Monitoring & Prevention

  • Monitor fuel filters carefully for signs of clogging.
  • Be aware of sludge formation and filter clogging, particularly after heavy weather.
  • Conduct regular sample analysis of fuel from before and after the purifier to confirm the unit’s efficiency.
  • Perform periodic cylinder scrape-down analysis to check for abrasive wear.
  • VPS also recommends taking fuel system check samples to assess the fuel treatment efficiency at the engine inlet or as close to it. This data is critical for any subsequent assessment of increased engine wear.

We would like to thank Veritas Petroleum Services for the above information.

 

Photo credit: Shaah Shahidh on Unsplash and VPS
Published: 23 September, 2025

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Bunker Fuel Quality

VPS: Importance of fast turnaround times for bunker fuel analysis in today’s market

Thomas Schmidt stressed the growing importance of rapid bunker fuel analysis amid the evolving marine fuels landscape, highlighting how VPS is meeting demand with fast, reliable testing services.

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Thomas Schmidt, Customer Account Manager of marine fuels testing company VPS, on Monday (18 May) highlighted how the company’s rapid, high quality marine fuel quality testing service continue to support the global shipping fleet, through a global network of strategically positioned laboratories, on-line logistics service and over 45 years of experience:

In today’s rapidly evolving marine fuel landscape, fast turnaround times for bunker fuel analysis have never been more critical.

Stricter environmental regulations and wider use of alternative fuels has generated increasingly complex marine fuel types and chemistries. In combination with volatile global supply chains and ongoing geopolitical instability, the need for ship operators and technical managers to have rapid and reliable fuel quality intelligence is increasingly important to protect their vessels, crew, operations, and commercial interests.

Following the introduction of IMO 2020, followed by further global and regional environmental legislation geared towards IMO2030/50, there has been a continuous development of lower-sulphur and low-carbon marine fuels, resulting in fuel quality variability across the global bunker market. Different blend components, cutter stocks, additives and bio-components can result in highly variable fuel behaviour and operational compatibility challenges.

At the same time, geopolitical developments continue to reshape global energy and bunker supply chains. Traditional product flows and refinery sourcing routes are changing, creating additional uncertainty around bunker fuel composition and quality consistency. Notably in 2026, the off-specification rate of fuels to relevant ISO8217 standards increased to 8.5%, from 6.8% during 2025.

Against this backdrop, timely fuel quality testing by an accredited laboratory is essential and remains one of the most effective tools available to ship operators, as advised by all major P&I Clubs. This helps to mitigate operational and financial risk by validating against ISO8217 specifications and providing operational guidance to onboard crew for effective handing and use.

Importance of Speedy Results

Fast turnaround time is critical for several reasons:

  • To assess fuel quality before the fuel is fully consumed onboard. Current fuel off-specification levels are 8.5% i.e. one in every twelve fuels has at least one off-specification parameter.
  • To identify potentially problematic fuels at an early stage.
  • Support fuel segregation, purification, compatibility and handling decisions.
  • Preserve contractual and claim-related rights, including applicable notification and potential time-bar requirements.
  • To reduce the risk of machinery damage, operational interruptions, delays, off-hire situations and costly troubleshooting cases. The Swedish P&I Club stated the average cost of a single marine fuel-related issue is >$330K.

The total turnaround time of a bunker sample is driven by a number of processes beginning with fuel delivery to the vessel and involves multiple critical stages:

  1.   Ensuring the taking of a representative fuel sample, (via a VPS manual drip sampler fitted at the vessel manifold).
  2.   Transfer of the sample to the local agent.
  3.   Sample Transfer via Courier to the laboratory.
  4.   Sample registration and laboratory analysis according to ISO8217 and additional testing requirements.
  5.   Technical review, interpretation and operational advice.
  6.   Report test results and advisory comments.

 

In many cases, the transportation phase alone may consume several days before the sample even arrives at the laboratory. 

How VPS Ensures Faster Turnaround Times

VPS has developed a fully integrated global fuel testing and advisory infrastructure, which currently boasts 93% of samples are reported within one working day from receipt in the laboratory.

SampLogic – Accelerating Sample Logistics to speed up transfer of sample to Lab

The VPS SampLogic platform is an online logistics and tracking solution designed specifically for marine fuel sample transportation, which is free for VPS customers and can save at least one full day on sample transportation. VPS Samplogic

SampLogic enables:

  • Online booking of bunker sample collection.
  • Automated generation of shipping documentation.
  • Shipment tracking and milestone visibility.
  • Faster coordination between vessel, agent, courier and laboratory.
  • By reducing manual processes and improving shipment transparency, SampLogic helps minimise transportation delays and accelerates the overall testing process.

Strategic Global Laboratory Network

VPS operates a global network of wholly-owned, ISO17025 accredited, marine fuel testing laboratories strategically located across the world’s major bunkering hubs in order to support the needs of our shipping customers.

The laboratories positioning further reduces sample transfer times whilst also providing important operational resilience and redundancy. During periods of geopolitical disruption, natural disasters, strikes or unexpected regional events, samples can be redirected within the VPS laboratory network to maintain continuity and avoid delays.

Technical Advisory Support

Analytical results alone are not sufficient in terms of assessing fuel-related operational requirements, fuel management and handling, or environmental compliance. It is the expert and experienced interpretation and advisory guidance which is where the major added-value is delivered to vessels from any fuel testing service.

VPS technical advisors and marine engineers located across the global laboratory network support customers with:

  • Troubleshooting.
  • Fuel management recommendations.
  • Risk assessments.
  • Operational guidance.
  • Dispute and claims support.

Where urgent fuel quality concerns are identified, VPS technical teams proactively contact customers to support immediate operational decision-making, with samples and results able to be progressed at pace, with VPS having supported numerous vessels in providing urgent results in the same working day to meet operational needs.

24/7 Digital Access Through VeriSphere

Through the VPS VeriSphere digital ecosystem, customers have continuous access to:

  • Analytical reports
  • Fuel quality trends
  • Historical fuel data
  • Market intelligence
  • Digital fuel management tools
  • Operational insights

This provides technical managers and vessel operators with rapid access to critical information anytime and anywhere.

In addition, the unique VPS PortStats, MyFuels and MySeparators, on-line applications within Verisphere, can provide deeper insights into global and regional fuel quality and key procurement indicators, plus operational and purifier performance improvements.

Conclusion

In the current climate, bunker fuel analysis is no longer simply a compliance exercise – it is an essential operational and procurement risk management tool.

As marine fuels continue to evolve and global supply chains become increasingly dynamic and unpredictable, rapid and reliable fuel quality intelligence is critical to protecting vessels, machinery, operations and commercial performance.

Minimising the total turnaround time from bunker sampling through to technical advisory support is therefore essential. Through its integrated logistics systems, strategic laboratory network, technical expertise and digital solutions, VPS continues to support the industry with fast, resilient and operationally focused fuel quality services.

 

Photo credit: VPS
Published: 19 May, 2026

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ECA

VPS examines North-East Atlantic ECA on current bunker fuel mix and testing

Impact of this new ECA, will not only affect bunker fuel selection and testing, but it will also require a review of, voyage planning, bunker procurement and scrubber strategy, amongst others.

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Steve Bee, Group Marketing and Strategic Projects Director, and Emilian Buksak, Decarbonisation Advisor of marine fuels testing company VPS, on Wednesday (8 April) highlighted MEPC 84 approved a new emission control area (ECA) covering the North-East Atlantic Ocean, with agreements reached on adopted amendments to MARPOL Annex VI. 

The new ECA, which will become the world’s largest emission control area, will be implemented on 1st September 2027

In a recent article, VPS outlined how VPS testing, data, CEM systems and advisory services can support vessels in both their operational and compliance challenges associated with this new ECA:

The recent International Maritime Organisation’s (IMO), Maritime Environmental Protection Committee (MEPC) meeting in London, had its main focus on setting binding greenhouse gas emission reduction targets for the global shipping sector. In keeping with the Committee’s continuing drive to decarbonise shipping and reduce the pollutant emissions from the global fleet, one major outcome from the MEPC-84 meeting was the approval of a new emission control area (ECA) covering the North East Atlantic Ocean, with agreements reached on adopted amendments to MARPOL Annex VI.

This new ECA, which will become the world’s largest emission control area, will be implemented on 1st September 2027, with the ECA requirements taking effect on 1st September 2028. It will cover the territorial seas and exclusive economic zones of Greenland, Iceland, the Faroe Islands, Ireland, the United Kingdom, France, Spain and Portugal, extending up to 200 nautical miles from their baselines:

VPS examines North-East Atlantic ECA impact on current bunker fuel mix and testing

A key advantage of the new NE Atlantic ECA is that it will close the gap between the existing ECAs in the North and Baltic Sea, plus the Mediterranean, creating an almost continuous zone of reduced shipping emissions. It will also connect to the newly approved ECAs in the Canadian Arctic and Norwegian Sea, which are scheduled for implementation in 2026 and 2027 respectively. Together these ECAs will cover almost half of all Arctic coastal waters, improving air quality, by reducing SOx, NOx and Particulate Matter (PM), protecting  public health, and reducing the environmental impacts from shipping.

The sulphur limit for the marine fuels allowed to be burnt within this new ECA will reduce from the current 0.50% to 0.10%. This will force vessels to use either effective abatement technology (scrubbers), or alternatively burn marine distillates, ultra-low-sulphur fuels (ULSFOs), or biofuels with a sulphur content of less than 0.10%.

Without doubt this new ECA will cause a significant change to the current fuel mix, probably on an even greater scale than was witnessed with the introduction of the Mediterranean ECA back in May 2025.  The fuel mix in the Mediterranean Pre-ECA implementation was,  53% VLSFO, 28% HSFO, 16% MGO, 2% ULSFO and 1% Biofuels. But from the 1st May 2025, the fuel mix changed to, 30% VLSFO, 29% HSFO, 30% MGO, 8% ULSFO and 4% Biofuels.  

So, in terms of actual tonnage, the Mediterranean ECA witnessed a decrease in VLSFOs by 23%, whilst MGO usage increased by 107%. At the same time, ULSFO and biofuels supply increased 4-fold.

Regarding fuel quality within the Mediterranean post-ECA implementation, MGO off-specification rates increased to 4%. However, the most worrying off-specification rates were for ULSFOs which saw a 10-times increase from 2% to 20% from the start of the ECA, with the main off-specification parameters being pour point, sulphur, TSP, CCAI, water and viscosity.

Therefore, it is fair to assume we’ll witness a similar dramatic fuel mix change upon the implementation of the NE Atlantic ECA, with possibly similar fuel off-specification issues, highlighting the continuing need for proactive fuel testing to protect vessels, crew and the environment.

Whilst the focus on fuel quality is essential, the multi-pollutant nature of this new ECA, covering SOx, PM and NOx, also brings the role of continuous emissions monitoring increasingly to the fore. Therefore, a further consideration relating to the impact of this new ECA relates to vessel newbuilds and the stricter NOx Tier III requirements. For newbuilds subject to the stricter NOx Tier III requirements, compliance depends not only on engine certification at delivery, but on demonstrating that exhaust after-treatment systems, typically Selective Catalytic Reduction (SCR) or Exhaust Gas Recirculation (EGR), continue to perform as designed throughout the service life of the vessel.

For scrubber-equipped ships, real-time SO₂ measurement provides the operational evidence of equivalency that Port State Control inspections increasingly expect to see. Plus, for vessels operating under multiple overlapping regulatory regimes, including the new NE Atlantic ECA, EU MRV, EU ETS and FuelEU Maritime, continuous emissions monitoring via the VPS EMSYS CEM system delivers a single, verified source of emissions data that can be applied across all of them.

As noted by DNV in their MEPC 84 technical and regulatory update, the newly adopted IMO measurement guidelines can also be used for determining actual methane and nitrous oxide under the EU ETS and FuelEU Maritime, confirming the direct route from IMO-recognised measurement to EU compliance reporting.

At an operational level, the new ECA will introduce considerable complexity in the way fuel consumption is attributed across voyage segments, with VLSFOs burnt outside the zone and compliant fuels inside, all of which carry implications for consumption reporting, charterparty allocation and EU MRV alignment. VPS Maress can provide the underlying fuel and energy data into one auditable platform, helping crews manage the operational complexity that the new ECA introduces, including voyage segmentation, fuel changeover and emissions accounting, plus providing the consolidated data foundation that feeds existing EU MRV and IMO DCS reporting obligations. 

VPS PortStats via the VPS Verisphere eco-system, (VeriSphere | VPS), further supports bunker procurement planning with port-by-port intelligence on compliant fuel availability and price spreads. Such intelligence and insights, will prove particularly valuable in the months immediately following 1st September 2028, when the supply pressure on 0.10% sulphur fuels is likely to peak.

Regarding the more strategic decisions ahead, including Tier III engine selection for newbuilds, retrofit feasibility for existing tonnage, and charterparty clauses allocating the ECA fuel cost premium between owners and charterers, VPS Advisory Services can provide the integrated commercial and technical perspective needed to navigate this transition with confidence.

Therefore, its clear the impact of this new ECA, will not only affect the choice of fuel to be burnt onboard and its subsequent quality testing, but it will also require a review of, voyage planning, bunker procurement, scrubber strategy, engine certification, compliance documentation and charterparty exposure.

Related: DNV on IMO MEPC 84: Revisiting Net‑Zero Framework

 

Photo credit: VPS
Published: 14 May, 2026

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Bunker Fuel Quality

FOBAS: Estonian shale oil and stability issues found in marine fuels from Singapore

FOBAS released a bulletin stating that tests on several fuels from Singapore identified a chemical fingerprint consistent with Estonian shale oil, while vessels using these fuels reported operational issues.

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Lloyd’s Register Fuel Oil Bunkering Analysis and Advisory Service (FOBAS) on Thursday (7 May) released a bulletin stating that tests on several fuels from Singapore identified a chemical fingerprint consistent with Estonian shale oil, while vessels using these fuels reported operational issues:

In recent weeks FOBAS has tested a number of fuels from Singapore that under detailed chemical analysis with GCMS methods, showed a chemical fingerprint consistent with Estonian shale Oil. 

Shale oil and particularly Estonian shale oil is seen from time to time in fuel blends in certain ports, particularly in Singapore and ARA region. In some of these recent fuels, the estimated concentrations are high, potentially up to 25% of the blend. 

The routine analysis results of these fuels appear on-spec compared to ISO8217 RMG380 grade fuels including Total Sediment results not particularly high.

The vessels using these fuels recently tested with confirmed shale oil are reporting certain operational issues, including excessive sludging throughout the fuel system, blocking of filters and in one case fuel pump issues.

As detailed chemical analysis is not carried out routinely on all fuels, it is difficult to say how many fuels may also have shale oil in the blend. However, from looking at other fuels properties and other supplies from the same barges and suppliers, we can estimate many other vessels have bunkered fuels with varying levels of Shale oil. Not all these ships have yet given operational feedback.

In general, shale oil is often seen as mentioned in certain ports and in many cases, fuels used without problem. However, there is also a long history of fuel stability and sludge related problems related to Estonian shale oil so while it seems not every shale oil blended fuel necessarily will cause a problem there certainly seems an increased risk and in particular in fuels with very high levels of shale oil.

We would suggest requesting from a supplier if shale oil has been used in the fuel blend when bunkering. Also paying particular attention to the Total Sediment results and fuel performance particularly though the purifier. We would also suggest fuels are put into use as soon as possible to quickly identify any potential issues and avoid long term storage.

 

Photo credit: Hans Reniers on Unsplash
Published: 8 May, 2026

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