Bunker Fuel Quality

VPS: High bunker prices meet declining fuel quality

Of the current 29 Bunker Alerts issued by VPS from January to July 2026, the combination of abrasive issues due to elevated cat-fines, plus fuel stability issues, account for 72% of these alerts.

Published

23 minutes ago

August 25, 2026

Admin

Steve Bee, Group Marketing and Strategic Projects Director of marine fuels testing company VPS, on Monday (24 August) reviewed 2026 marine fossil fuel quality to date and the high number of issues being witnessed:

Marine fuel buyers entered 2026 facing a perfect storm, suffering some of the highest bunker prices ever experienced, paired with a sharp and concerning decline in fuel quality. Across the traditional marine fossil fuel supply chain, VPS has seen a marked rise in fuel quality issues, with the Middle East conflict playing a major role in driving both price volatility and quality deterioration. For ship owners/operators, the message is clear, today’s fuel market is not only more expensive, it is also becoming more complex and unpredictable, with a higher degree of operational risk.

This deterioration is already showing itself in the test data VPS have produced. Between January and July 2026, VPS issued 29 Bunker Alerts, more than the total issued across the whole of 2024 and already closing in on the 37 alerts recorded throughout all of 2025. In just seven months of 2026, the scale and frequency of these alerts underline a clear, accelerating rise in fuel quality problems across the industry. Of the current 29 Bunker Alerts issued so far, Jan-Jul 2026, the combination of abrasive issues due to elevated cat-fines, plus fuel stability issues, account for 72% of these alerts. The ports requiring cat-fines and/or stability-related bunker alerts were, ARA, Balboa, Busan, Callao, Hamburg, Houston, Las Palmas, Philadelphia, Piraeus, Rotterdam, San Roque, Singapore and Valencia.

What is of additional interest is that marine gas oil does not account for a single Bunker Alert so far in 2026. It is HSFO and VLSFO dominating the fuels requiring such warnings.

VPS: High bunker prices meet declining fuel quality

Looking at the rate of off-specifications across each of the main marine fossil fuel types, HSFO is currently running at 8.87% of samples tested, being off-specification for at least one ISO8217 test parameter, whilst VLSFO has 9.88% off-specification level, MGO has 9.03% and ULSFOs is at 19.58%. ISO 8217 provides specification requirements for marine fuel as delivered to the ship. From a commercial perspective the fuel is only required to meet the specification at the point of custody transfer, ie at the ship’s manifold. However, compliance at this point, is not a guarantee of assurance that the fuel can be used without operational difficulties throughout its onboard lifecycle. This includes, how the fuel is stored, treat and consumed in main engines, generator engines, boilers, or other machinery. The condition of the fuel which ultimately reaches the machinery, is also strongly influenced by onboard fuel management, including storage and settling temperatures, settling time, purification temperature and throughput, purifier configuration and desludging arrangements, filtration, maintenance of the correct injection viscosity and other operational factors.

This is why knowing the characteristics of the bunkered fuel is critical to managing it correctly onboard. Appropriate testing can identify characteristics which, although not necessarily resulting in an ISO 8217 specification failure, may warrant additional operational attention. VPS therefore evaluates bunker fuels not only against the applicable specification requirements, but also provides operational advice where analytical findings indicate that additional precautions may be appropriate during storage, treatment or consumption.

VPS testing and observations, based on over 45 years of marine fuel testing experience and expertise, strongly align with a recent Linkedin post by marine and energy consultants, Brookes Bell. Their post highlighted a growing concern within the industry, stating a P&I Club had reported that bunker-related claims are up 50% this year, with many of the fuels involved having technically passed ISO8217 standard specification testing.

The same post noted that some ISO8217-compliant fuels have still caused operational damage. This has left shipowners to manage complex evidentiary disputes after problems arose. Its key warning was clear: Standard compliance testing alone isn’t catching the problem. If “passing spec” is not necessarily the same as being “safe-to-burn”, then the critical question becomes, “What additional testing is needed to identify the real operational risks?”

VPS have recognised that for some time, the ISO8217 standard is not an all-encompassing set of tests providing the highest level of asset, crew and environmental protection. For this reason, VPS offer a range of additional tests, as well as our Additional Protection Service (APS) test bundles. For example in the case of avoiding damages from cat-fines, the Fuel System Check (FSC) service, can provide valuable information in regard to monitoring purifier efficiency and the removal of cat-fines, protecting the engine to a higher degree. Whereas, Separability Number testing, is a key compliment to the hot filtration stability tests of TSP, TSA and TSE in mitigating stability risks. Should additional cold-flow information be required, the VPS proprietary Wax Appearance Temperature (WAT) testing provides key storage and fuel transfer temperature information. Whilst the VPS chemical screening services can identify potentially harmful chemicals within a fuel before the fuel is burnt. Then more detailed Gas Chromatography Mass Spectrometry (GCMS) forensic analysis provides key information to potentially support the fuel claims process.

VPS account managers and technical specialists can help shipowners and operators determine which laboratory tests are most appropriate for their fleet, based on the fuel characteristics, vessel operations and potential risk exposure. This guidance can support the mitigation of risks linked to engine damage, SOLAS compliance, legislative requirements and wider operational reliability.

The VPS Technical Advisory Team reviews bunker analysis results together with the vessel operational observations to provide practical advice on fuel storage, handling, purification and overall fuel management. Where appropriate, additional laboratory tests, or test bundles, may be recommended to further evaluate the fuel and assist in identifying the cause of an operational issue, supporting more informed decision-making.

VPS continues to monitor regional and global fuel quality trends through its laboratory network and customer feedback. Information received from vessels experiencing similar operational issues is valuable in helping VPS identify emerging trends and provide timely technical guidance to the wider shipping industry.

Photo credit: VPS
Published: 25 August, 2026

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Bunker Alerts

Low flashpoint found in Indonesia bunker fuels, alerts Maritec-Naias

Firm tested eight bunker samples representing LSMDO and B40 fuel grade from vessels that took fuel oil /bunkered in Indonesia ports, which indicated flashpoints as low as 39.5°C.

Published

2 weeks ago

August 13, 2026

Admin

Bunker fuel testing and marine surveying business Maritec-Naias on Wednesday (12 August) issued an alert regarding bunker samples from vessels that took fuel oil/bunkered in Indonesia showing flashpoints as low as 39.5°C:

During the period of 21 July to 04 August 2026, Maritec-Naias tested eight bunker samples representing Low Sulfur Marine Distillate Oil (LSMDO) and B40 fuel grade from vessels that took fuel oil /bunkered in Indonesia ports, which indicated Flashpoints as low as 39.5°C.

All eight fuel samples tested were sourced from a single supplier.

Regulatory Implications:

Based on the results of the eight samples tested, the fuels do not comply with the minimum flashpoint requirement of 60 °C set by SOLAS and ISO 8217.

As per SOLAS requirements, the minimum flashpoint of any fuel carried in the tanks of a ship should be not less than 60 °C (with exception of fuel for lifeboats, which can be grade DMX with a flash point min of 43 °C).

ISO 4259 interpretation for tested flashpoint temperature is not taken into consideration here as the safety of onboard crew and vessel is of higher precedence.

Since 01 May 2024, it has been a MARPOL Annex VI requirement that the Bunker Delivery Note (BDN) includes either the actual flashpoint of a fuel as supplied or a declaration that its flashpoint has been determined as being at or above 70°C.

From 1 January 2026, SOLAS amendments clarified that the flashpoint requirement applies to fuels, which were specifically intended to have a flashpoint not less than 60°C as required under SOLAS II‑2/2.1.1 These amendments now align with MARPOL by requiring flashpoint details to be recorded on the BDN. Additionally, prior to bunkering, suppliers must provide the ship’s representative with a signed declaration confirming that the fuel meets the SOLAS flashpoint standard.

MARITEC-NAIAS RECOMMENDATIONS

When ordering fuels from Indonesia it is advised to insist on getting the actual flash point values from the supplier. If your vessel has bunkered a low flashpoint fuel it is prudent to observe/implement the precautions below:

Flame screens on tank vents should be maintained in good condition and there should be no sources of ignition in the vicinity of the vents. This will assist in safe natural ventilation of volatile components in the fuel.
No Smoking, no naked flame and no hot work must be allowed at any areas near to tank air vents.
Send additional tank(s) samples upon arrival in port to check the fuel properties and flash point results especially if there has been co-mingling of fuels in bunker tanks
If the vessel is out at sea, it may be possible to obtain dispensation from your Flag State Administration up to the next arrival port.
Put the supplier on notice promptly and notify your P&I club.

Photo credit: Shaah Shahidh on Unsplash
Published: 13 August, 2026

Bunker Alerts

Maritec-Naias: High levels of Phenolic compounds in China bunker fuels

Firm tested multiple fuel oil bunker samples from vessels that took fuel/bunkered in China ports from 7 June to 28 July, which indicated the presence of high levels of Phenolic compounds.

Published

2 weeks ago

August 12, 2026

Admin

Bunker fuel testing and marine surveying business Maritec-Naias on Friday (7 August) issued an alert regarding high levels of Phenolic compounds found after conducting testing on multiple fuel oil bunker samples from China ports:

During the period of 07 June to 28 July 2026 Maritec-Naias tested multiple fuel oil bunker samples from vessels that took fuel/bunkered in China ports, which indicated the presence of high levels Phenolic compounds.

Ten cases were found to have Phenolic compounds, and its derivatives, in the range of 5200 – 15750 PPM. Out of ten cases, the fuel samples tested were sourced as follows: four from Tianjin port, two from Qinhuangdao port, two from Rizhao port, one from Zhoushan port, and one from Shandong port.

The fuel samples containing Phenolic compounds in excess of 5000 PPM returned a marginally stable classification (P-value 1.00 to <1.30) under the SMS 1600 stability reserve test. Prolonged storage of these fuels carries the risk of reduced fuel stability and resulting operational issues. Operational issues like excessive sludge formation in purifiers, filter choking and fuel pump wear-and-tear have been observed and reported when similar levels of phenolic compounds were present in a vessel’s bunker fuel.

Phenolic compounds in the bunker fuel samples were precisely identified using Gas Chromatography-Mass Spectrometry (GC-MS) with both Direct Liquid Injection (DLI) and Solid Phase Extraction (SPE) methods, ensuring robust detection. The detected chemical compounds may have originated from the following sources:

1) liquid fuels derived from coal-tar
2) shale-derived oil

Regulatory Implications:

Due to the high levels of these chemical compounds the fuels render unacceptable under the section of general requirement in the standard ISO8217:2010 and MARPOL Annex VI regulation 18, irrespective of Table 2 compliance.

General requirements as per para 5 of ISO8217:2010 states below:

“5.2 The fuel shall be homogeneous blends of hydrocarbons derived from petroleum refining. This shall not preclude the incorporation of small amounts of additives intended to improve some aspects of fuel characteristics and performance. The fuels shall be free from inorganic acids and from used lubricating oils.

5.3 The fuel shall be free from any material that renders the fuel unacceptable for use in marine applications.

5.5 The fuel shall not contain any additive at the concentration used in the fuel, or any added substance or chemical waste that

a) jeopardizes the safety of ships or adversely affects the performance of the machinery; or
b) is harmful to personnel; or
c) contributes overall to additional air pollution.”

MARITEC-NAIAS RECOMMENDATIONS

Closely observe the vessel fuel system/s for signs of filter clogging and purifier sludging and additionally, increase vigilance on the centrifuges to monitor overloading.
Increase frequency of their de-sludging cycle depending on the accumulated sludge.
Possibly reduce the mean time between bowl cleaning of the purifier and fuel system filters.
Avoid blending with other fuels, in particular marine diesel and gas oil and also other fuel oil as such mixing may well increase the sediment problem.

Photo credit: Louis Reed from Unsplash
Published: 12 August, 2026

Bunker Fuel Quality

Bunker flash: High levels of chemical compounds found in Malaysia, alerts Maritec-Naias

During the period of 15 April to 15 July 2026, Maritec-Naias tested multiple fuel oil bunker samples from vessels that took fuel/bunkered in Malaysia ports.

Published

2 weeks ago

August 11, 2026

Admin

Bunker fuel testing and marine surveying business Maritec-Naias on Monday (10 August) issued an alert regarding high levels of chemical compounds found in multiple fuel oil bunker samples from vessels that have taken fuel/bunkered in Malaysia ports:

During the period of 15 April to 15 July 2026, Maritec-Naias tested multiple fuel oil bunker samples from vessels that took fuel/bunkered in Malaysia ports, which indicated the presence of high levels chemical compounds.

Five cases were found to have Phenolic compounds and Alkylresorcinols in the range of 1070 – 9994 PPM and three cases were found to have reactive hydrocarbons in the range of 4500 – 20000 PPM. Operational issues like excessive sludge formation in purifier and wear-and-tear of the fuel pump were reported.

Gas Chromatography-Mass Spectrometry (GC-MS) testing using the Solid Phase Extraction (SPE) method confirmed the presence of Alkylresorcinols in samples tested. In addition, GC-MS ASTM D7845 analysis identified a range of phenolic compounds and reactive hydrocarbons – including styrene and its derivatives, dicyclopentadiene, dihydro-dicyclopentadiene, and indene – providing comprehensive evidence of contamination.

The presence of Alkylresorcinols may originate from non-petroleum cutter stocks, such as Estonian shale oil, while the detected reactive hydrocarbons could stem from ethylene cracker by-products. In addition, the fuels appear to have been blended with low-quality marine fuels, a practice likely driven by sharply rising bunker prices amid the war in the Middle East.

Regulatory Implications:

Due to the high levels of these chemical compounds the fuel does not meet the general requirement and is considered as off-spec fuel as per clause 5 of ISO8217 and MARPOL Annex VI regulation 18, which states:

“The fuels shall be homogeneous blends of hydrocarbons derived from petroleum refining. This shall not preclude the incorporation of small amounts of additives intended to improve some aspects of performance. The fuels shall be free from inorganic acids and from used lubricating oils. The fuel should not include any added substance or chemical waste which,

a) jeopardizes the safety of ships or adversely affects the performance of the machinery; or
b) is harmful to personnel; or
c) contributes overall to additional air pollution.”

MARITEC-NAIAS RECOMMENDATIONS

Closely observe the vessel fuel system/s for signs of filter clogging and purifier sludging and additionally, increase vigilance on the centrifuges to monitor overloading.
Increase frequency of their de-sludging cycle depending on the accumulated sludge.
Possibly reduce the mean time between bowl cleaning of the purifier and fuel system filters.
Avoid blending with other fuels, in particular marine diesel and gas oil and also other fuel oil as such mixing may well increase the sediment problem.
Opt for Maritec-Naias’s highly cost-effective Marine Fuel Testing Programme (MFTP) PLUS testing for all residual bunker fuel. This package includes routine ISO 8217 Testing, targeted GC-MS screening for 38 high-risk compounds relevant to ship operations & P-value Stability Testing – providing crucial pre-burn protection against fouled purifiers, blocked injectors & engine failure.

Photo credit: Hans Reniers on Unsplash
Published: 11 August, 2026