Marine bunker trading, brokerage & supply coordination · Port of Singapore
Residual fuel · 0.50% sulphur
Very low sulphur fuel oil for vessels without scrubbers, sourced from MPA-licensed physical suppliers and specified to the ISO 8217 grade and edition you require.
VLSFO, very low sulphur fuel oil, is a residual marine fuel with a sulphur content of no more than 0.50% m/m. It became the main fuel for ocean-going ships without exhaust gas cleaning systems when the MARPOL Annex VI global sulphur limit fell from 3.50% to 0.50% on 1 January 2020.
VLSFO is not a single recipe. Refiners and blenders produce it from different combinations of low sulphur residues, hydrotreated streams, cracked components and distillates, so two VLSFO deliveries can differ noticeably in density, viscosity, pour point and aromatic content even when both meet the same ISO 8217 grade. That variability is the main reason procurement teams need to look beyond price when buying VLSFO.
In Singapore, VLSFO is the highest-volume bunker grade and is traded daily by many MPA-licensed suppliers. Most is sold at the RMG 380 grade, with lower viscosity grades such as RME 180 or RMD 80 available from some suppliers on request.
Specifications
VLSFO is bought against a residual grade in ISO 8217, typically RMG 380, with the sulphur limit set at the statutory 0.50% m/m. The viscosity grade describes the fuel’s maximum kinematic viscosity at 50°C. It says nothing about sulphur.
| Parameter (RMG 380) | Limit (ISO 8217:2017) |
|---|---|
| Kinematic viscosity at 50°C | max 380.0 mm²/s |
| Density at 15°C | max 991.0 kg/m³ |
| CCAI | max 870 |
| Sulphur | statutory limit: 0.50% m/m for VLSFO |
| Flash point | min 60.0°C |
| Total sediment, aged | max 0.10% m/m |
| Aluminium + silicon | max 60 mg/kg |
| Water | max 0.50% v/v |
| Pour point | max 30°C |
ISO 8217:2024 revised several residual fuel parameters and added bio-residual grades. If your charter party specifies the 2024 edition, state it in the enquiry so the supplier confirms against the correct table.
Vessel applications
Two-stroke main engines on container ships, bulk carriers and tankers operating outside emission control areas.
Medium-speed main and auxiliary engines designed for residual fuel, subject to the engine maker’s viscosity range.
Auxiliary boilers on vessels that burn residual fuel, where the burner system is suitable.
Scrubber-fitted vessels sometimes carry VLSFO for periods when the scrubber cannot be used.
Operational considerations
Because VLSFO blends vary, two compliant fuels can be incompatible when mixed. Asphaltenes can fall out of solution and form sludge that blocks filters and purifiers. Best practice is to load into empty or nearly empty tanks, avoid commingling with previous stock, and ask for a compatibility test if mixing cannot be avoided.
Some paraffinic VLSFOs have high pour points and wax appearance temperatures. Tank heating should be planned before loading, particularly when the vessel is heading to colder waters after Singapore.
Catalytic fines (aluminium and silicon) can come from cracked blend components. Effective purification, with separators set for the fuel’s density and viscosity, is essential.
The sulphur figure on the bunker delivery note is the supplier’s declaration. Under MARPOL Annex VI, verification uses the retained MARPOL sample, and the in-use and on-board samples taken from the vessel’s own system. Keep sample records in order in case of port State control checks.
Procurement & delivery
VLSFO is delivered by MPA-licensed bunker tankers at the anchorages or alongside, with quantity measured by mass flow meter under SS 648 and documented on an e-BDN. We confirm the delivery window with the supplier, give the agent the supplier details, and pass on ETA changes. VLSFO is often combined with LSMGO in a single stem.
Samples are drawn during delivery. Many owners send a sample for independent testing before using a new stem. We can arrange an independent bunker surveyor and laboratory testing against ISO 8217.
Use the bunker quotation form and select the VLSFO grade. Include vessel name, IMO number, ETA, delivery window, location and quantity in metric tons. See also VLSFO vs HSFO.
It is a very low sulphur fuel oil (sulphur at most 0.50%) at the 380 viscosity grade, meaning a maximum kinematic viscosity of 380 mm²/s at 50°C, usually ISO 8217 grade RMG 380. The 380 refers to viscosity, not sulphur.
VLSFO is the most widely traded grade in Singapore and is normally available from several licensed suppliers, but availability for a specific date, location and quantity is always confirmed per enquiry.
It is best avoided. VLSFOs from different sources can be incompatible. Load into separate tanks where possible, or obtain a compatibility test before mixing.
The fuel is delivered by an MPA-licensed bunker supplier. SingaporeBunker.com sources and coordinates the purchase, and the delivering supplier is named in the written offer.
Send the vessel, ETA, grade, specification edition and quantity. We will return offers from suitable MPA-licensed suppliers.