VLSFO vs HSFO: What Every Vessel Operator in West Africa Needs to Know
Since the International Maritime Organization’s 2020 global sulfur cap came into force, the conversation around marine fuel has fundamentally shifted. VLSFO — Very Low Sulfur Fuel Oil — went from an emerging product to the dominant choice for vessels operating outside Emission Control Areas almost overnight. Yet despite its now-widespread adoption globally, questions around VLSFO quality, compatibility, and sourcing remain very much alive, particularly for operators in West Africa.
At Stratos Trading, VLSFO is central to what we do. We ventured into VLSFO trading in 2022 and have since consolidated significant export and bunker trade volumes in the product. We have seen firsthand how operators navigate the VLSFO versus HSFO decision, and we want to share what we know.
This article is for vessel operators, procurement managers, and shipping companies seeking clarity on the two fuel types, their regulatory status, and how to source VLSFO reliably in West African waters.
A Quick Primer: What Are VLSFO and HSFO?
Before getting into the comparison, it helps to establish what each product actually is.
HSFO — High Sulfur Fuel Oil — is the traditional heavy fuel oil that powered the global shipping industry for decades. It is a residual product, meaning it is what remains after lighter fractions have been extracted during the refining process. It is energy-dense, relatively cheap to produce, and historically very widely available. The catch is its sulfur content, which can reach up to 3.5% mass by mass.
VLSFO — Very Low Sulfur Fuel Oil — is a marine fuel blend engineered to comply with the IMO 2020 sulfur limit of 0.50% mass by mass. It is not a single standardised product in the way that something like MGO (Marine Gas Oil) is. VLSFO is blended to meet the sulfur cap, and its composition can vary significantly between suppliers and regions. This variability is one of the most important things vessel operators need to understand.
The Regulatory Picture: Why HSFO’s Role Has Fundamentally Changed
The IMO 2020 sulfur cap is the defining regulation here, and it is worth being precise about what it does and does not prohibit.
Burning HSFO without an approved exhaust gas cleaning system (commonly known as a scrubber) is now prohibited in international waters and ports for vessels subject to MARPOL Annex VI. Vessels fitted with scrubbers can still use HSFO, as the scrubber reduces sulfur oxide emissions to an equivalent or lower level than burning compliant low-sulfur fuel.
In practice, this means:
Vessels with scrubbers: HSFO remains a viable and cost-effective fuel choice. The economics of the scrubber payback calculation versus the VLSFO/HSFO price spread determine whether the investment makes sense.
Vessels without scrubbers: VLSFO (or MGO in Emission Control Areas) is the compliant choice. There is no legal option to burn HSFO in international waters without a scrubber.
For most operators in West Africa, where scrubber penetration is lower than in some other regions, VLSFO is the practical default. And that means the quality and reliability of VLSFO supply matters enormously.
The Key Differences Between VLSFO and HSFO
Understanding the practical differences between these two fuel types helps operators make better procurement and operational decisions.
Sulfur Content
This is the headline difference. HSFO typically contains between 2.5% and 3.5% sulfur. VLSFO contains a maximum of 0.50%. The environmental implication is significant: burning VLSFO produces substantially lower sulfur oxide emissions, reducing both regulatory risk and environmental impact.
Energy Density and Viscosity
HSFO is generally denser and more viscous than VLSFO, which affects how it is handled, stored, and burned. VLSFO blends can vary considerably in their viscosity, and this variability has been a source of operational challenges for some vessel operators, particularly around fuel system compatibility and cold flow properties.
Before switching to a new VLSFO blend, it is worth checking compatibility with your vessel’s fuel system and confirming the product specifications with your supplier.
Price
Historically, VLSFO has traded at a premium over HSFO due to the additional refining and blending costs required to reduce sulfur content. That premium fluctuates with crude oil prices and regional supply dynamics, but the general principle holds. For vessels without scrubbers, however, this is not a choice — it is a compliance requirement.
Availability and Quality Consistency
This is where West Africa presents specific challenges. VLSFO is now widely available in major global bunkering hubs, but in West African ports, quality and availability can vary significantly depending on the supplier’s sourcing network and storage infrastructure.
This is precisely why Stratos Trading has invested heavily in a diversified sourcing network spanning modular refineries, government-owned facilities, and the Dangote Refinery, along with dedicated storage at Greenmac Energy Terminal. Consistent supply requires consistent infrastructure.
VLSFO Quality: What Operators Need to Watch For
Because VLSFO is a blended product rather than a defined single product, quality monitoring is particularly important. Here are the key things to look out for.
Compatibility Issues
VLSFO blends can be incompatible with each other if mixed, which can lead to sludge formation in fuel tanks and filters. When changing suppliers or receiving a new blend, operators should conduct compatibility testing where possible and flush systems carefully.
Stability
Some VLSFO blends have shown stability issues, meaning the fuel can separate or form deposits over time. Checking the Total Sediment Potential (TSP) value of any fuel before it enters your system is good practice.
Cold Flow Properties
Depending on your trading route, the cold filter plugging point (CFPP) of VLSFO matters. Some blends can solidify or become difficult to pump in cooler temperatures. This is less of a concern for vessels operating in West Africa’s warm waters but is worth keeping in mind for vessels transitioning between regions.
Certificates of Quality and Quantity
We cannot stress this enough. Every VLSFO delivery should come with a Certificate of Quality confirming that the product meets the relevant ISO 8217 specification, and a Certificate of Quantity confirming the volume delivered. At Stratos Trading, these certificates accompany every single supply we make. If a supplier cannot provide them, do not take the fuel.
Why VLSFO Sourcing in West Africa Requires a Different Level of Due Diligence
The global VLSFO market is mature and well-supplied. The West African market is catching up, but it is not yet there in terms of uniformity of standards and supplier quality.
The region has a significant number of informal operators who may offer competitive pricing but lack the infrastructure, certification, and documentation to supply fuel that protects both your vessel and your compliance record.
When evaluating a VLSFO supplier in West Africa, the questions to ask include:
Are they NMDPRA-approved for bunker supply and trading operations?
Are they an IBIA member?
Do they hold ISO certifications covering quality, environmental, and occupational health management?
Do they have their own storage infrastructure and a dedicated fleet of supply barges?
Can they provide Certificates of Quality and Quantity on every delivery?
These are not bureaucratic questions. They are the practical tests that distinguish a supplier built for long-term, reliable partnerships from one that may let you down at a critical moment.
How Stratos Trading Approaches VLSFO Supply
When we entered the VLSFO market in 2022, we did so with a clear intention: to bring the same rigour and reliability to VLSFO trading in West Africa that international clients expect from global bunkering hubs.
Our sourcing network gives us access to product from multiple refinery sources, which means we can maintain supply even when individual refineries face outages or production constraints. Our 20,000MT+ storage capacity at Greenmac Energy Terminal allows us to hold segregated product grades and load vessels efficiently. And our fleet of five dedicated bunker barges gives us direct control over the delivery process.
Every VLSFO supply we make is backed by full documentation, ISO-certified quality management processes, and a team with the technical expertise to advise on product specifications, compatibility, and handling.
We have consolidated significant VLSFO export and bunker trade volumes since 2022, and we continue to grow that capability as demand in West Africa increases.
Conclusion
The choice between VLSFO and HSFO is, for most vessel operators in West Africa today, largely settled by regulation. Unless your vessel is equipped with a scrubber, VLSFO is your compliant fuel, and the quality of that fuel depends almost entirely on the quality of your supplier.
Understanding what VLSFO is, how it differs from HSFO, and what to look for in a supplier is not just technical knowledge — it is commercial and operational protection.
At Stratos Trading, we have built our VLSFO supply capability around exactly the standards that vessel operators in West Africa need. If you are looking for a reliable, certified, and well-documented VLSFO supply partner in the region, we would be glad to talk.
Reach out to us at tradefinance@stratostrading.net or visit stratostrading.net.