MARPOL
The IMO convention preventing pollution from ships: oil, chemicals, sewage, garbage and air emissions, across six annexes.
- Category
- Regulation and Compliance
- Annexes
- six (I to VI)
- Annex VI sulphur cap
- 0.50% global
- Dictionary entry
- MARPOL
- Last reviewed
How it works
MARPOL, the International Convention for the Prevention of Pollution from Ships, is the principal global treaty on ship-source pollution. Its six annexes cover oil (I), noxious liquids (II), packaged harmful substances (III), sewage (IV), garbage (V) and air pollution (VI).
Annex VI is the one driving the energy-transition rules: it caps sulphur in marine fuel (a global limit, and tighter limits inside emission control areas), restricts NOx, and houses the EEDI, EEXI and CII framework.
Where it shows up on The Maritime
Also known as: MARPOL, marpol annex vi, marpol convention.
The short dictionary definition is at Dictionary entry: MARPOL. This page is the explainer.
Related terms
International Maritime Organization (IMO)
The United Nations agency that sets global rules for ship safety, security and pollution prevention.
Very Low Sulphur Fuel Oil (VLSFO)
Marine fuel blended to the global sulphur cap: the compliant fuel for most waters since the IMO sulphur rules took effect.
Scrubber
An exhaust gas cleaning system that removes sulphur oxides from a ship’s emissions, letting her burn cheaper high-sulphur fuel.
Carbon Intensity Indicator (CII)
An IMO operational measure of how much CO₂ a ship emits per unit of transport work, graded A to E each year.
Energy Efficiency Existing Ship Index (EEXI)
A one-time IMO design-efficiency standard that existing ships must meet, the in-service counterpart of the EEDI for new ships.
More regulation and compliance terms
A 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: .