Understanding your BDN parameters, ISO 8217 limits, and what happens when fuel is off-spec — a practical guide for fleet operators.
The Bunker Delivery Note is the official document provided at every fuel delivery. MARPOL Annex VI requires it to include: date, port, supplier, vessel details, fuel quantity, fuel type, density, viscosity, and sulfur content. The BDN must be retained onboard for 3 years and is subject to Port State Control inspection.
But the BDN only tells part of the story. The values printed on the BDN are typically from the supplier's own test report — not an independent analysis. This is why independent lab testing (FOBAS, VPS) is essential for quality assurance.
Aluminium and silicon catalyst particles from refinery cracking. The single most damaging fuel contaminant. At levels above 15 mg/kg (onboard limit after purification), cat fines cause accelerated wear on cylinder liners, piston rings, and fuel injection equipment. A single bad stem can cost $50,000-200,000 in engine damage.
Measured in kg/m³ at 15°C. Affects purifier separation efficiency. Above 991 kg/m³, conventional purifiers cannot effectively separate water and sediment from fuel. High density fuel requires slower purifier throughput or modern variable-frequency purifiers.
Resistance to flow, measured in cSt (centistokes) at 50°C. Determines heating requirements for proper injection atomization. Too high = poor atomization, incomplete combustion. Too low = insufficient lubrication of fuel pumps and injectors.
Calculated Carbon Aromaticity Index — indicates ignition quality. Derived from density and viscosity. Values above 870 indicate poor ignition characteristics, leading to incomplete combustion, after-burning, and thermal stress on engine components.
Regulated under IMO 2020 global sulfur cap. VLSFO must be ≤0.50%. HSFO (with scrubber) has no practical limit. Non-compliance results in Port State Control detention, fines up to $50,000+, and criminal prosecution in some jurisdictions.
Water contamination above 0.10% causes injector corrosion, microbial growth in tanks, and reduced heating value. At 0.50%+ (ISO limit), fuel is considered off-spec. Water is the most common adulteration method — easy to add, hard to detect without lab testing.
The supplier tests their own fuel before delivery. The BDN reports the supplier's results. Without independent verification, you're trusting the seller to grade their own product.
Independent labs (FOBAS by Lloyd's Register, VPS by Veritas) test fuel from your retained sample using calibrated equipment and standardized methods. Results typically available within 7-14 days.
TRIVOYA automates the comparison: when lab results are entered, the system compares against BDN values parameter by parameter. Deviations exceeding thresholds trigger automatic dispute creation with estimated claim value.
Cat fines (catalytic fines) are aluminium and silicon particles from refinery cracking catalysts. At levels above 15 mg/kg onboard, they act like sandpaper inside your engine — causing accelerated wear on cylinder liners, piston rings, and fuel injection equipment. A single bad stem with high cat fines can cost $50,000-200,000 in engine damage. This is why independent lab testing is essential — BDN values consistently underreport cat fines by 40-60%.
VLSFO (Very Low Sulfur Fuel Oil) has sulfur content ≤0.50% and is the default fuel under IMO 2020 global sulfur cap. HSFO (High Sulfur Fuel Oil) has higher sulfur content (typically 2.5-3.5%) and can only be used with an approved exhaust gas cleaning system (scrubber). VLSFO is typically $80-120/MT more expensive than HSFO, but vessels without scrubbers have no choice.
Best practice is to test every delivery through FOBAS or VPS. The cost is approximately $200-400 per sample — negligible compared to the potential engine damage from off-spec fuel. At minimum, test every delivery from unfamiliar suppliers or ports with known quality issues. TRIVOYA's supplier quality database helps identify which suppliers and ports require extra vigilance.
First, notify the chief engineer immediately to adjust purifier settings and fuel treatment. Second, retain all documentation — BDN, lab report, and fuel samples. Third, file a formal quality claim with the supplier within the timeframe specified in your bunker contract (typically 30 days). TRIVOYA automates this process — when lab results deviate beyond thresholds, a dispute case is auto-created with estimated claim value and all supporting evidence.
Conventional centrifugal purifiers cannot effectively separate water and sediment from fuel with density above 991 kg/m³ at 15°C. This means contaminants pass through to your engine. High-density fuel requires either slower purifier throughput (reducing available fuel supply rate) or modern variable-frequency purifiers. Fuel above 991 is technically off-spec under ISO 8217 for most grades.
30-day free pilot. We onboard your fleet, import your data, and deliver your first intelligence report.
Schedule a Demo →