IMO Marine Environment Protection Committee (MEPC 84) –Key Regulatory Outcomes

The 84th session of the IMO Marine Environment Protection Committee was held from 27 April to 1 May 2026, addressing key regulatory developments in marine environmental protection, air pollution prevention, energy efficiency, ballast water management, marine plastic litter and GHG reduction from ships.

Key outcomes included:

MARPOL Annex VI amendments adopted (expected enter into force date 1 September 2027)

The draft amendments to MARPOL Annex VI regarding to Clarification of entries in data reporting required by regulations 27 and 28, designation of the North-East Atlantic as an Emission Control Area for Nitrogen Oxides, Sulphur Oxides and Particulate Matter, accessibility to the IMO Ship Fuel Oil Consumption Database, and review clause of the short-term GHG reduction measure were adopted.

Further amendments to MARPOL Annex VI were adopted regarding the use of multiple engine operational profiles for marine diesel engines and clarification of engine test cycles.

Ballast Water Management Developments

The draft amendments to the BWM Convention were approved with a view to adopt at the next session.

2026 Guidelines for ballast water management and development of Ballast Water Management Plans (G4) was adopted.

The Committee approved the unified interpretation to regulation D-3 of the BWM Convention and decided to include in BWM.2/Circ.66.

Energy Efficiency and CII Framework Updates

EEDI framework updated: Dual-fuel engines using methanol and ethanol were included in EEDI calculations through adopted amendments to the EEDI calculation and certification guidelines.

CII and SEEMP guidelines amended: Amendments were adopted to the CII Guidelines (G1) and the 2024 SEEMP Guidelines to maintain consistency with enhanced IMO DCS reporting and carbon intensity calculations.

Methane (CH4) and Nitrous Oxide (N2O) measurement guidelines adopted: MEPC 84 adopted new guidelines for test-bed and onboard measurements of methane and nitrous oxide emissions, including Engine Load Monitoring (ELM) and Continuous Emission Monitoring Systems (CEMS). Their voluntary use was agreed.

Energy Efficiency & Underwater Radiated Noise

A draft MEPC circular providing guidance on the joint optimization of energy efficiency and underwater radiated noise during ship design and retrofit was approved.

GHG Reduction and IMO Net-Zero Framework

Progress continued on the IMO Net-Zero Framework, detailing both technical and economic mid-term measures. The Terms of Reference for the 5th IMO GHG Study were also finalized to provide a robust evidence base for future strategies.

Marine Plastic Litter

The 2026 Strategy and Action Plan to Address Marine Plastic Litter from Ships was adopted, reaffirming IMO’s target of zero plastic waste discharges to sea from ships by 2030.