The ARA complex has emerged as the key sulfur risk area for VLSFO, according to Integr8 Fuels‘ Bunker Quality Trends report for the first half of 2025.

9.5% of the VLSFO samples tested had elevated sulfur levels of 0.51-0.53%, which is within the 95% tolerance band, the report shared by Integr8 highlighted.

1.7% of the samples had sulfur content above the tolerance band and off-spec.

By contrast, Singapore maintained a far stronger compliance profile, with only 1.4% of samples in the borderline range and 0.2% off spec, leaving ARA with an eight-fold higher probability of non-compliance.

“Interestingly, the risk distribution inside ARA remains uneven,” the report said.

“Core bunkering points such as Rotterdam and Antwerp show manageable off-spec rates of 1-2% yet still record almost one sample in ten sitting in the tolerance band.”

The report points to blending practices and possible cross-contamination from barges carrying both HSFO and VLSFO as contributing factors.