Marine fuel testing company VPS has reported widespread contamination of very-low-sulphur fuel oil (VLSFO) with elevated catalytic fines (cat fines) levels across six major bunkering locations between August 11-31, 2025.

The contamination, detected through VPS's fuel quality testing service, affected supplies in East Coast USA, Singapore, Rotterdam, Hamburg, Algeciras, and Port Louis, with cat fines levels — a combination of aluminium and silicon particles — ranging from 62ppm to 176ppm.

According to Steve Bee, Group Marketing & Strategic Projects Director at VPS, the issue prompted the release of seven VPS Bunker Alerts during the three-week period, with Bee himself referring to the sequence of events in recent weeks as a "global pandemic".

The East Coast USA experienced the highest contamination levels, with fuel from a single supplier in Boston and New York containing cat fines between 70ppm-176ppm. Singapore recorded levels of 67ppm-156ppm across four suppliers, while Algeciras saw contamination ranging from 61ppm-92ppm from two suppliers.

In European ports, Rotterdam had three suppliers delivering fuel with cat fines levels between 61-78ppm, and Hamburg recorded levels of 62ppm-66ppm from two suppliers. Port Louis reported the lowest contamination range at 63-65ppm across three suppliers.

VPS warns that elevated levels of these abrasive particles can cause accelerated wear to diesel engine components including piston rings, cylinder liners, and fuel pumps if not reduced to acceptable levels.

Cat fines are catalyst particles that can remain in marine fuel oil following the refining process and pose risks to engine performance when present in excessive quantities.

VPS says it is offering support to shipowners and operators affected by high cat fines contamination.