Very Low Sulphur Fuel OilVLSFO
Marine fuel with no more than 0.50% sulphur, the compliant fuel for most waters under the IMO 2020 sulphur cap.
Very Low Sulphur Fuel Oil (VLSFO) is a residual marine fuel blended to meet the 0.50% global sulphur limit that took effect under MARPOL Annex VI in January 2020 (often called "IMO 2020"). Inside Emission Control Areas the limit is tighter still at 0.10%.
Ships either burn compliant fuels like VLSFO and marine gas oil or keep burning high-sulphur fuel oil with an exhaust scrubber. The price spread between VLSFO and high-sulphur fuel determines the economics of fitting a scrubber.
On The Maritime
Also known as: VLSFO, very low sulphur fuel oil, IMO 2020 fuel.
Related terms
Scrubber
An exhaust gas cleaning system that removes sulphur oxides from a ship’s emissions, letting her burn cheaper high-sulphur fuel.
Bunkers
The fuel a ship burns — and, by extension, the act of taking on that fuel (bunkering). Usually the single largest voyage cost.
MARPOL
The IMO convention preventing pollution from ships — oil, chemicals, sewage, garbage and air emissions across six annexes.
International Maritime OrganizationIMO
The United Nations agency that sets global rules for ship safety, security and pollution prevention.
Plain-English reference definition — our own explanation of a standard shipping concept, not a licensed source or legal advice. See the full glossary or the broader maritime dictionary.
Last reviewed: June 2026.