The 84th session of MEPC was held from April 27th to May 1st, 2026, at IMO Headquarters in London. The meeting highlights are as follows:
(1) Promoting Consensus on the “IMO net zero framework (NZF).”
MEPC 84 resumed discussions on the regulatory measures that were suspended during the Extraordinary Session in October 2025 (MEPC/ES.2) and established a dedicated working group to address related concerns. Moving forward, the Intersessional Working Group on Reduction of GHG Emissions from Ships (ISWG-GHG) will convene to continue drafting implementation guidelines that support the Net Zero Framework, while also considering options to reconvene an Extraordinary Session. It is anticipated that the ISWG-GHG will further develop relevant guidelines to support the execution of various elements within the proposed IMO Net Zero Framework.
(2) Refining the Life Cycle GHG Assessment (LCA) Framework and Launching the 5th GHG Study
Progress continues on developing the Life Cycle GHG Assessment (LCA) framework for marine fuels. Concurrently, planning has begun for the "Draft Terms of Reference for the 5th IMO GHG Study," which is scheduled to be launched later in 2026 and completed in 2028.
(3) Advancing the Regulatory Framework for Onboard Carbon Capture and Storage (OCCS)
①. Establishment of Three Core Principles:
(I) Incorporate CO₂ permanent mineralization technologies;
(II) Onboard emissions are to be verified by the Administration (The responsible entity for issuing certificates after the offloading of CO₂ on board the vessel remains to be discussed);
(III) Consider OCCS at the "ship level" within the Greenhouse Gas Fuel Intensity (GFI) guidelines.
②. Outstanding Issues for Future Resolution:
Further work is required to define the system boundaries under the Life Cycle Assessment (LCA) framework and to clarify the legal compliance of discharging CO₂ into the ocean under conventions such as the London Protocol.
③. Next Steps:
The Correspondence Group has been reconstituted to continue drafting guidelines for calculation, verification, and certification, with a report expected to be submitted to MEPC 86 (October 2027).
The draft amendments to MARPOL Annex I, which include the introduction of a new Regulation 12B to permit the controlled dewatering of oily bilge water by forced evaporation, have been approved in principle. Additionally, the draft guidelines for Integrated Bilge Water Treatment Systems (IBTS) on oily waste handling and machinery space operations have received approval in principle. However, these remain subject to final approval at MEPC 85 in conjunction with the formal adoption of the amendments to MARPOL Annex I.
MEPC 84 considered and adopted the draft amendments to MARPOL Annex VI, which encompass the following elements:
(1) New designation of the North-East Atlantic Ocean area as an Emission Control Area (ECA) for Nitrogen Oxides (NOx), sulphur oxides (SOx), and particulate matter (PM).
(2) Clarification of the data reporting entries required under Regulation 27 and Regulation 28, relating to the information to be submitted to the IMO Ship Fuel Oil Consumption Database (Regulation 27) in Appendix IX, and enhancing the public accessibility of the IMO Data Collection System (IMO DCS). The IMO DCS requires ships to record and report their fuel oil consumption, and the relevant data is utilized to calculate the ship's operational Carbon Intensity Indicator (CII).
(3) Revisions to the definitions and the format of Appendix I "International Air Pollution Prevention Certificate" (IAPP Certificate) related to the use of multiple engine operational profiles for marine diesel engines, including clarifications on engine test cycles.
These amendments will enter into force on 1st September 2027, with the 0.10% sulphur limit taking effect 12 months later. The requirement for NOx Tier III engine certification will apply to ships for which the building contract is placed on or after 1st January 2027; or in the absence of a building contract, ships the keels of which are laid or which are at a similar stage of construction on or after 1st July 2027; or ships delivered on or after 1st January 2031.
MEPC 84 considered the outcomes of the 13th session of the Sub-Committee on Pollution Prevention and Response (PPR 13) regarding matters relating to Exhaust Gas Cleaning Systems (EGCS), NOx emissions, and Black Carbon.
(1) NOx Technical Code
MEPC 84 finalized and approved draft amendments to the NOx Technical Code to address the certification of engines operating on non-carbon fuels and fuel mixtures. These amendments establish a clear regulatory framework for certifying NOx emissions from gas-fueled engines.
Furthermore, MEPC 84 approved amendments regarding the use of multiple engine operational profiles and the clarification of engine test cycles. These amendments will apply to new engine groups and engine series certified on or after 1st January 2028.
(2) Volatile Organic Compounds (VOCs)
As a measure to reduce volatile organic compound (VOC) emissions, MEPC 84 approved draft amendments to Regulation 15 of MARPOL Annex VI, requiring crude oil tankers to be fitted with pressure-vacuum valves (P/V valves) with a minimum opening pressure of 0.20 bar. These amendments are subject to adoption at MEPC 85 in November 2026, and this requirement will apply only to crude oil tankers constructed on or after the date of entry into force of the amendments.
(1) Amendments to the BWM Convention and the conclusion of the Experience-Building Phase (EBP)
Based on the EBP review, the Committee approved several draft amendments to the Convention. These draft amendments are expected to be formally adopted at MEPC 85 (November 2026) and to enter into force in the spring of 2028. At that time, the EBP and its associated non-penalization measures will officially terminate.
(2) Strengthening Ballast Water Management Plans (Revision of Guidelines G4)
MEPC 84 also adopted the revised Guidelines for ballast water management and development of Ballast Water Management Plans (Guidelines G4), which consolidate existing IMO circulars and guidelines. The revised Guidelines G4 introduce a mandatory requirement for a ship's Ballast Water Management Plan (BWMP) to incorporate and record the following matters (the implementation of which will be linked to the entry into force of the aforementioned Convention amendments):
①. Contingency measures (BWM.2/Circ.62);
②. Management of Challenging Water Quality (CWQ) conditions (Resolution MEPC.387(81));
③. Temporary storage of treated sewage and/or greywater in ballast water tanks, where applicable (BWM.2/Circ.82); and
④. Maintenance procedures, maintenance schedules, and references to the Ballast Water Management System operational manuals.
The requirements for Ballast Water Management Plans have been strengthened by introducing relevant mandatory specifications into Section B of the BWM Convention. The application of the revised guidelines will be linked to the entry into force of the amended BWM Convention text, the date of which will be determined upon adoption of the amendments at MEPC 85.
Furthermore, the MEPC advanced its work to finalize draft amendments to the mandatory Ballast Water Management Systems Code (BWMS Code) and furthered the revision and development of guidelines associated with the BWM Convention, including high-performance testing incorporating more stringent test water conditions and durability testing requirements. A correspondence group was re-established to finalize amendments to the type approval under the BWMS Code for consideration at the next session of the MEPC in November 2026, and to continue the revision of existing guidelines and development of new ones, with a view to reporting to MEPC 86 in October 2027.
MEPC 84 initiated Phase II of the IMO's review of short-term GHG reduction measures, scheduled for completion by 2028. These measures, adopted in 2021 and entered into force in 2022, comprise the Energy Efficiency Existing Ship Index (EEXI), the enhanced Ship Energy Efficiency Management Plan (SEEMP), and the Carbon Intensity Indicator (CII) rating mechanism.
There was broad support within the Committee to strengthen the SEEMP framework to ensure continuous improvement in ship carbon intensity. The proposed elements include internal reviews, implementation logs, and enhanced auditing requirements, which will be further discussed and finalized at MEPC 86 in October 2027.
In addition, the Committee adopted amendments to the guidelines on the method of calculation and survey/certification of the Energy Efficiency Design Index (EEDI) to clarify the definition of the primary fuel for dual-fuel engines using two liquid fuels, specifically methanol and ethanol. The amendments further specify that the determination of engine power and specific fuel consumption should be based on the Maximum Continuous Rating (MCR) certified in accordance with the NOx Technical Code 2008.
References:
1. American Bureau of Shipping (ABS), News Brief: MEPC 84. https://ww2.eagle.org/en/rules-and-resources/regulatory-updates/regulatory-news/MEPC84.html
2. Bureau Veritas (BV), Marine Environment Protection Committee 84th session (MEPC 84) Summary Report. https://marine-offshore.bureauveritas.com/newsroom/marine-environment-protection-committee-84th-session-mepc-84-summary-report
3. Class NK, Preliminary Report of IMO MEPC 84. https://www.classnk.or.jp/hp/pdf/info_service/imo_and_iacs/MEPC84_sumE.pdf
4. Det Norske Veritas (DNV), Key outcomes of MEPC 84 – Focus on IMO’s Net‑Zero Framework. https://www.dnv.com/news/2026/imo-mepc-84-revisiting-the-net-zero-framework/
5. European Parliament, On the path towards decarbonization of maritime transport: Key issues at stake at the IMO MEPC 84. https://www.europarl.europa.eu/RegData/etudes/BRIE/2026/780423/ECTI_BRI(2026)780423_EN.pdf
6. InterManager, Summary report on IMO Marine Environment Protection Committee (MEPC 84). https://www.intermanager.org/2026/05/re-summary-report-on-imo-marine-environment-protection-committee-mepc-84-27-april-1-may-2026-169151/
7. International Maritime Organization (IMO), PREVIEW: Marine Environment Protection Committee (MEPC 84), 27 April to 1 May 2026. https://www.imo.org/en/mediacentre/meetingsummaries/pages/preview-mepc-84.aspx
8. Lloyd’s Register (LR), MEPC 84 Summary Report. https://www.lr.org/en/knowledge/regulatory-updates/imo-meetings-and-future-legislation/mepc-84-summary-report/
9. 中國船級社(CSS)，〈國際海事組織海上環境保護委員會第84屆會議(MEPC 84)要點快報〉。https://www.ccs.org.cn/ccswz/IMOMeetingDetail?columnid=201900002000000037&articleId=202605070380520615