Answer
Current enforceable Chapter 5
Under the 2021 Revised MARPOL Annex VI, in force from 1 November 2022, Chapter 5 is:
“Verification of compliance with the provisions of this Annex”
It consists of:
Regulation 30 — Application
Parties shall use the provisions of the Code for Implementation, i.e. the IMO Instruments Implementation Code (III Code), when carrying out their obligations under Annex VI.
Regulation 31 — Verification of compliance
It requires every Party to be subject to periodic IMO audits to verify implementation and compliance with Annex VI.
The regulation covers:
- IMO Member State audits
- Secretary-General administration of the Audit Scheme
- State responsibility to facilitate audits
- corrective action to address audit findings.
“Under the presently applicable 2021 Revised MARPOL Annex VI, Chapter 5 is Verification of Compliance with the provisions of Annex VI. It contains Regulation 30 – Application, and Regulation 31 – Verification of Compliance, and links implementation of Annex VI with the III Code and IMO Member State Audit Scheme.”
Draft Chapter 5 is the IMO Net-Zero Framework.
That relates to the draft revised Annex VI developed for the IMO Net-Zero Framework. The proposed framework would insert a new Chapter 5 containing a marine fuel GHG-intensity standard and an economic/pricing mechanism, shifting verification provisions to Chapter 6.
However, the extraordinary MEPC session in October 2025 did not complete adoption, and IMO announced that net-zero shipping talks would resume in 2026.
Key Pillars of draft Chapter 5 (IMO Net-Zero Framework)
1. Goal-Based Marine Fuel Standard (Technical Element)
- Mandates a progressively tightening trajectory for the Well-to-Wake (WtW) GHG intensity of energy used on board (gCO2 eq/MJ).
- Covers the entire lifecycle of energy sources—from extraction and production through combustion—forcing a shift from conventional fossil fuels to biofuels, synthetic e-fuels, LNG with low methane slip, Methanol, and Ammonia.
2. Maritime GHG Emissions Pricing Mechanism (Economic Element)
- Establishes a global economic mechanism (GHG levy/financial contribution system) integrated directly into the framework.
- Feebate Structure: Ships using energy above the mandatory GHG intensity threshold pay a financial penalty per ton of emissions into an IMO fund. Vessels using zero- or near-zero GHG fuels receive rewards to offset the price gap between fossil and green fuels.
Comparison for MEO Class 1 Examinations
Feature | Chapter 4 (Energy Efficiency) | Chapter 5 (IMO Net-Zero Framework) |
|---|---|---|
Focus | Technical design & operational efficiency (how efficiently the vessel uses energy). | Fuel lifecycle GHG intensity & fuel switching (what type of energy the vessel burns). |
Primary Metrics | EEDI, EEXI, SEEMP, and CII (gCO2/dwt-nm). | Well-to-Wake GHG Intensity (gCO2 eq /MJ) and economic contributions. |
Boundary | Tank-to-Wake (TtW / shipboard combustion). | Well-to-Wake (WtW / full supply chain lifecycle). |
Compliance Target | Annual operational ratings (A through E). | Mandatory fuel standard target limits and economic levy compliance. |