The International Convention for the Prevention of Pollution from Ships (MARPOL Agreement ) is a well-established primary international convention by the International Maritime Organization (IMO) to control ship-borne pollution, across the global maritime shipping sector covering accidental spills and operational waste like oil, sewage, garbage, and air emissions, through six technical Annexes that set strict rules for handling contaminants, with specialized requirements like oil record books, double hulls for tankers, and bans on plastic dumping, aiming for cleaner waters and preserved marine ecosystems.
Annex 6 is the IMO treaty preventing air pollution from ships, setting limits on Sulphur Oxides (SOx), Nitrogen Oxides (NOx), and Ozone Depleting Substances (ODS), while also addressing greenhouse gases (GHG) and volatile organic compounds (VOCs), with stringent standards in Emission Control Areas (ECAs) and focusing on fuel oil sulfur content, engine efficiency, and the release of pollutants from ship operations.
Historical Overview and Key Dates of MARPOL Annex 6.
- 1973: The original International Convention for the Prevention of Pollution from Ships (MARPOL) was adopted by the International Maritime Organization (IMO). It covered oil, chemicals, sewage, and garbage pollution, but did not initially include air pollution.
- 1978: A Protocol was adopted in response to numerous tanker accidents. This combined instrument (MARPOL 73/78) absorbed the parent convention and came into force in 1983.
- 1997: The 1997 Amendments to MARPOL were adopted, introducing Annex 6: Regulations for the Prevention of Air Pollution from Ships
- May 19, 2005: Annex 6 officially entered into force internationally after being ratified by countries representing a sufficient percentage of the world's merchant shipping tonnage.
- 2008: A major revision to the Annex was adopted, which introduced more stringent limits for sulphur oxide (SOx) and nitrogen oxide (NOx) emissions, including the global 0.50% sulphur limit confirmed for 2020
- 2011: A new chapter was added to Annex VI, making the Energy Efficiency Design Index (EEDI) and Ship Energy Efficiency Management Plan (SEEMP) mandatory to address greenhouse gas (GHG) emissions and improve energy efficiency
- 2018: The Initial IMO strategy on reduction of GHG emissions from ships was adopted, setting a path for future climate action in shipping.
- January 1, 2020: The global limit for sulphur content in ship fuel oil was reduced significantly to 0.50% m/m from the previous 3.5% m/m limit, a major cut in SOx emissions ("IMO 2020" sulphur limit).
- November 1, 2022: Further amendments took effect, introducing mandatory obligations for existing ships to calculate their attained Energy Efficiency Existing Ship Index (EEXI) and annual operational Carbon Intensity Indicator (CII) rating.
- August 1, 2025: Amendments requiring enhanced data collection and reporting on fuel oil consumption (IMO DCS) are planned to enter into force.
What are the awaited main actions in 2026?
In 2026, the primary developments awaited for MARPOL Annex 6 will be the entry into force of new Emission Control Areas (ECAs), Enhanced IMO DCS Data Collection, SEEMP Amendments and continued progress on the IMO's Net-Zero Framework.
- MARPOL Annex 6 Emission Control Areas (ECAs) are designated maritime zones with strict rules limiting ship emissions (Sulfur Oxides - SOx, Nitrogen Oxides - NOx, Particulate Matter - PM) to protect human health and the environment, requiring cleaner fuels or advanced abatement tech, with current ECAs such as the Baltic Sea, North Sea, North American coasts, and the Caribbean (US waters).
This regulation stands as an important step for the industry to prevent harmful emissions, offering guidance for safer shipping practices. These areas enforce lower fuel sulfur limits (0.10% vs. global 0.50%) and stricter NOx limits (Tier III), significantly reducing air pollution in coastal areas and mitigating its impacts on human health and the ecosystem.
New ECAs Entering into Force on March 1, 2026.
Amendments adopted by the International Maritime Organization (IMO) at MEPC 82 will formally designate the Canadian Arctic and the Norwegian Sea as new ECAs. While the amendments enter into force on March 1, 2026, the specific requirements phase in with different timelines:
- NOx Tier III Standards: The stricter Tier III NOx limits for marine diesel engines (over 130 kW) will become applicable in these areas from March 1, 2026, but only for ships that meet specific construction criteria related to their building contract, keel-laying, or delivery dates.
- SOx and Particulate Matter (PM) Standards: The requirement for ships to use fuel with a sulphur content not exceeding 0.10% m/m (mass by mass) will be enforced from March 1, 2027, which is 12 months after the amendments enter into force, providing a grace period for a smooth transition.
- A key event in 2026 will be the reconvening of the IMO Marine Environment Protection Committee's (MEPC) second extraordinary session in October. The session was adjourned in October 2025 due to a lack of consensus. Discussions will continue on the adoption of the comprehensive IMO Net-Zero Framework, which includes:
- A global fuel standard with a mandatory emissions intensity limit.
- A global greenhouse gas (GHG) emissions pricing mechanism.
- The potential formal designation of the North-East Atlantic Ocean as a new ECA for SOx, PM, and NOx.
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- Enhanced IMO DCS Data Collection
Existing ships (5,000 GT and above) that did not voluntarily start collecting enhanced data in January 2025 must begin collecting more granular fuel consumption and transport work data from January 1, 2026. This data collection is part of the IMO Ship Fuel Consumption Database (IMO DCS) to monitor operational carbon intensity.
The enhanced data includes reporting fuel consumption by specific consumer groups (e.g., main engine, auxiliary engines, boilers) and splitting the data into "underway" and "not underway" categories.
Amendments will ensure that all reported data in the IMO DCS is accessible to Parties to Annex 6 in a non-anonymized format, while an anonymized database will be made available to the public.
Ship owners and operators should ensure necessary equipment (like flow meters) and procedures are in place to meet the January 1, 2026, deadline for data collection
The enhanced data collection requires specific reporting of fuel consumption by consumer type and operational status:
- Fuel oil consumption per consumer type and fuel type (e.g., main engines, auxiliary engines).
- Fuel oil consumption while not underway per consumer type and fuel type.
- Onshore power supplied to the ship.
- Total transport work (cargo carried multiplied by distance travelled).
- Laden distance travelled (on a voluntary basis).
- Installation of innovative technologies.
The data collected throughout the 2026 calendar year will be submitted for verification no later than March 31, 2027, to receive the Statement of Compliance (SoC).
In 2026, the key actions regarding the MARPOL Annex 6 SEEMP Amendments will be the mandatory collection of enhanced, granular fuel oil consumption data by all existing ships for the entire calendar year and the implementation of updated SEEMP Parts II (Ship Energy Efficiency Management Plan) and III (for Carbon Intensity Indicator (CII) implementation plan) that must be on board the ship by January 1, 2026.
As mentioned earlier, In 2026, the main awaited action regarding the IMO's Net-Zero Framework under MARPOL Annex 6 is the resumed extraordinary session of the Marine Environment Protection Committee (MEPC) to vote on the formal adoption of the framework's legal text. The decision was delayed from October 2025 due to a lack of consensus among member states.
The primary action will be the reconvened MEPC extraordinary session, likely in October 2026, where members will again consider the adoption of draft amendments to MARPOL Annex 6. The framework includes two key, linked elements:
- A global fuel standard that requires ships to gradually reduce their annual greenhouse gas fuel intensity (GFI).
- A global GHG emissions pricing mechanism (or economic measure) where ships exceeding GFI thresholds must acquire "remedial units" to balance their emissions deficit.
- Leading up to the resumed session, IMO Member States will continue negotiations to build consensus on the framework.
Meanwhile, The Intersessional Working Group on the Reduction of GHG Emissions from Ships will continue developing the detailed guidelines for implementing the Net-Zero Framework, regardless of the delay in the legal framework's adoption.
Why the above-mentioned are Important to Know?
- Commercial Viability: These regulations directly impact operating costs through new fuel requirements, potential GHG pricing, and regulatory reporting obligations.
- Environmental Compliance: Failure to adapt to enhanced data collection or new ECA rules can lead to detentions, fines, and port restrictions.
- Strategic Planning: Ship-owners and operators need to carefully study the upcoming regulatory changes to plan for cleaner fuels, retrofits, and potential route adjustments to meet IMO’s de-carbonization targets.
- Global Standardization: The NZF aims to create a level playing field, but navigating the complex framework requires understanding upcoming deadlines and provisions.
- Future-Proofing Vessels: Decisions made now on technology and fuel sourcing will determine a ship's compliance and competitiveness in the coming years.
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