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
