On April 29, FOBAS released a bulletin concerning fuel samples from vessels that reported issues with fuel injection equipment, specifically the malfunction of jerk-type fuel pumps, that bunkered fuel in Istanbul during March and April 2025.
As explained, the fuel samples were subjected to extended chemical analysis, revealing the presence of several chemical substances, including 4-Cumyl Phenol, Cyclohexane Diol, Resin acids, Acrylates, Dicyclopentadiene (DCPD), Indene, and trace amounts of Tetrachloroethylene. Some of these chemicals, particularly those used in resin and plastic manufacturing, can polymerize under heat and pressure, potentially causing problems in the fuel injection system.
Despite the fuels being on-spec based on routine analysis, the bulletin notes unusual parameters such as low viscosity (around 40cSt) and high acid numbers (1.50 – 2.50 mg KOH/g), which align with patterns observed in problem fuels from other regions in the past.
FOBAS suggests that vessels which bunkered in Istanbul in the last 2-3 months, particularly those with low viscosity (<50cSt), high acid numbers (>1.00 mg KOH/g), or high sediments, should be cautious and consider further testing. The issue may not be limited to just two vessels.
The bulletin also reminds suppliers that any fuel purchased in accordance with the ISO8217 standard must meet the general requirements outlined in Clause 5, which specifies that the fuel should be a homogeneous blend of hydrocarbons and free from harmful substances or chemical waste that could jeopardize ship safety or machinery performance.
