1. Purpose
This Newsletter is issued to inform PHRS Surveyors, Auditors, Head Office personnel and interested stakeholders of the main outcomes of the 84th session of the IMO Marine Environment Protection Committee, MEPC 84, held at IMO Headquarters in London from 27 April to 1 May 2026. MEPC 84 addressed several important environmental and regulatory matters, including greenhouse gas reduction measures, energy efficiency, ballast water management, air pollution prevention, marine plastic litter, underwater radiated noise, oil pollution prevention and protected sea areas.
2. IMO Net-Zero Framework and GHG Reduction Measures
MEPC 84 continued discussions on the IMO Net-Zero Framework and the development of mid-term greenhouse gas reduction measures. However, no final agreement was reached at this stage, as Member States continued to hold different views on the way forward, including whether the framework should be adopted with limited changes or further adjusted to reflect market readiness and fuel availability.
Discussions will continue through two intersessional working groups on GHG reduction before MEPC 85. MEPC 85 is tentatively scheduled for 30 November to 3 December 2026, while the resumed MEPC ES.2 is planned for 4 December 2026, subject to further discussion.
MEPC 84 also completed the terms of reference for the Fifth IMO GHG Study, which is expected to support the review of the IMO GHG Reduction Strategy in 2028.
3. Review of Short-Term GHG Measures — EEXI, CII and SEEMP
MEPC 84 continued the review of the IMO short-term GHG reduction measures, including EEXI, CII and SEEMP. The Committee adopted amendments to the EEDI calculation and survey/certification guidelines in order to better address dual-fuel ships. It was also clarified that, for the time being, the existing CII calculation methodology remains unchanged, using supply-based transport work as the basis for calculating attained annual operational CII.
Further discussions were held on strengthening SEEMP requirements, including the possible introduction of regular internal reviews, continuous improvement arrangements, clearer accountability, stronger audit arrangements and an Energy Efficiency Implementation Log. This work was not finalized and will continue at a future session.
Proposals related to a CII metric for adverse weather and a revised metric for cruise passenger ships were also discussed but were not agreed at this stage.
4. Ballast Water Management
MEPC 84 approved draft amendments to the Ballast Water Management Convention. The amendments place stronger emphasis on the actual performance, maintenance and operation of Ballast Water Management Systems, rather than only their installation and type approval.
In practice, shipowners and operators will need to demonstrate that BWMS are properly maintained, functioning effectively and achieving the D-2 discharge standard. Surveyors and Port State Control are expected to focus more closely on maintenance records, alarms, failures, corrective actions and crew familiarization.
The amendments also introduce requirements concerning updated and controlled Ballast Water Management Plans, BWMS maintenance records, reporting of failures, repair planning, and active substance controls. The amendments are expected to be adopted at MEPC 85, with an anticipated entry into force in May 2028. MEPC 84 also adopted MEPC.409(84) — 2026 Guidelines for Ballast Water Management and development of Ballast Water Management Plans (G4).
5. MARPOL Annex VI and Air Pollution Prevention
MEPC 84 adopted amendments to MARPOL Annex VI, including the designation of the North-East Atlantic as an Emission Control Area (ECA) for nitrogen oxides, sulphur oxides and particulate matter. The new ECA covers areas including Greenland, Iceland, the Faroe Islands, the western coasts of the United Kingdom and Ireland, and extends southwards towards Spain and Portugal.
For SOx requirements, ships operating in the area will be required to use fuel oil with sulphur content not exceeding 0.10% m/m from 1 September 2028. NOx Tier III requirements will apply to ships constructed according to the relevant dates specified in the adopted amendments.
Further amendments were also adopted to align MARPOL Annex VI with the NOx Technical Code regarding the use of multiple engine operational profiles for marine diesel engines.
6. IMO DCS, Fuel Consumption Data and Transparency
MEPC 84 considered developments related to the IMO Data Collection System. Amendments to MARPOL Annex VI will enhance access to fuel oil consumption data, including access by Administrations and Recognized Organizations to data for their ships, and wider access to anonymized data for analysis and transparency purposes. These amendments are expected to enter into force on 1 September 2027.
7. Methane, Nitrous Oxide and Emission Measurement Guidelines
MEPC 84 adopted new guidelines related to the measurement and monitoring of methane and nitrous oxide emissions from marine diesel engines. These include guidelines for test-bed and onboard measurements, engine load monitoring and continuous emission monitoring systems. The guidelines are intended to support more accurate and verifiable assessment of tank-to-wake emissions, particularly in the context of alternative fuels and future GHG frameworks.
8. Marine Plastic Litter from Ships
MEPC 84 adopted the 2026 Strategy and Action Plan to Address Marine Plastic Litter from Ships. The Committee also agreed that further work should continue on the development of a mandatory code for the maritime transport of plastic pellets in freight containers, together with possible amendments to MARPOL Annex III and/or SOLAS. Further work will also continue on fishing gear marking systems, voluntary reporting of lost or discharged fishing gear, and data collection on waste generated by ships during normal operations.
9. Underwater Radiated Noise
MEPC 84 continued its work on underwater radiated noise from ships, recognizing the potential impact of commercial shipping noise on marine life, particularly marine mammals. The Committee agreed in principle to extend the experience-building phase for the reduction of underwater radiated noise until 2028. It also approved MEPC.1/Circ.924, providing technical guidance on co-optimizing energy efficiency and underwater radiated noise at the design and retrofit stage.
10. Oil Pollution Prevention and Protected Areas
MEPC 84 approved the development of a new MARPOL Annex I regulation permitting the use of integrated bilge water treatment systems, together with supporting guidance. The Committee also agreed to the new Nasca Ridge, Peru, Particularly Sensitive Sea Area associated protective measure, and considered further proposals relating to an Arabian Sea PSSA and a Nasca Ridge MARPOL Special Area.
11. PHRS Follow-Up
PHRS will continue to monitor the outcome of MEPC 84 and any subsequent developments at MEPC 85 and related IMO working groups. The adopted and approved amendments, guidelines and future work items will be reviewed to identify any impact on PHRS Rules, procedures, survey instructions, checklists, forms, certification activities and training material.
Further guidance will be issued, as necessary, following publication of the relevant IMO resolutions, circulars and implementation instructions.