ANNEX
Six Technical Annexes
Oil, noxious liquid substances in bulk, packaged harmful substances, sewage, garbage, air pollution, and energy efficiency.
MARPOL · International Convention for the Prevention of Pollution from Ships · Reay's Note
MARPOL Regulatory FrameworkSummary Notes
MARPOL is the international convention framework for preventing pollution from ships. Its scope covers oil pollution, noxious liquid substances in bulk, harmful substances in packaged form, sewage, garbage, air pollution, and greenhouse gas emissions. In practice, it is not merely a set of discharge limits, but a compliance system linking design, equipment, certificates, operations, records, and shore reception facilities.
Framework Overview
SYS
Four-Layer Regulatory Structure
Convention articles, Annex, Regulation, and Appendix / Guideline.
OPS
Compliance Is Not Just Equipment
Equipment, piping, certificates, record books, and actual operations must remain consistent.
PSC
High PSC Relevance
Oil Record Books, Garbage Record Books, BDNs, SEEMP, and related records are often key evidence.
Article FocusCore Idea
The point of MARPOL is not a single rule or a single item of equipment. It connects pollution sources, shipboard controls, operational records, shore reception, and authority verification into an auditable pollution prevention system.
01 | Structure
Read MARPOL from its legal framework to shipboard implementation.
MARPOL is formally built on the 1973 Convention and the 1978 Protocol, commonly referred to as MARPOL 73/78. The 1997 Protocol later added Annex VI. In practice, it is useful to read MARPOL in four layers: convention articles, technical annexes, chapter regulations, and appendices or guidelines.
１
Convention / Protocols
The convention and protocols define Party obligations, amendment procedures, entry-into-force arrangements, and the implementation framework.
２
Annex I–VI
The six pollution categories are the main practical entry points for survey, PSC, ship management, and company SMS verification.
３
Chapters / Regulations
The chapters and regulations within each Annex define requirements for surveys, certificates, discharge controls, equipment, and record books.
４
Appendices / Guidelines
Certificate forms, record book formats, IMO guidelines, and operational details determine how compliance is documented on board.
Convention CoreEstablishes the international minimum requirements for preventing pollution from ships.
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Technical AnnexesBreaks down equipment, discharge, recordkeeping, and response requirements by pollution category.
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Shipboard ImplementationTranslates requirements into certificates, equipment, piping, operations, records, and shore reception arrangements.
02 | Overview
The six Annexes correspond to six pollution sources.
The technical core of MARPOL is Annex I to Annex VI. Different ship types, cargoes, trading areas, and operating patterns trigger different Annex requirements. From a management perspective, first identify the pollution source, then trace it back to certificates, equipment, and records.
👇 Select a card below to jump to the relevant explanation section.
Annex I
Oil PollutionAnnex II
NLS in BulkNoxious Liquid Substances in Bulk
Annex III
Packaged HarmfulMarine Pollutants
Annex IV
SewageAnnex V
GarbageAnnex VI
Air + GHGAir Pollution & Energy Efficiency
Pollution-source oriented
Equipment and piping
Certificates and records
Shore reception facilities
PSC / RO / flag State verification
| Annex | Topic | Control Focus | Common Documents / Verification Points |
|---|---|---|---|
| Annex I | Oil Pollution | Controls machinery-space bilge water, tanker cargo areas, oil residues, oily water discharge, and oil pollution emergency response. | IOPP Certificate, Oil Record Book Part I/II, 15 ppm OWS, ODME, SOPEP, sludge tanks, and STS plan. |
| Annex II | Noxious Liquid Substances in Bulk | Controls bulk liquid cargo residues, tank washings, prewash, and discharge from chemical tankers. | NLS Certificate, Cargo Record Book, P&A Manual, and cargo categories X/Y/Z/OS. |
| Annex III | Harmful Substances in Packaged Form | Manages harmful substances carried in packaged form, identified as marine pollutants under the IMDG Code, or meeting Annex III criteria. | IMDG Code, dangerous goods declaration, labels, stowage plan, and document consistency. |
| Annex IV | Sewage | Controls shipboard sewage discharge, sewage treatment equipment, and sewage holding tanks. | ISPP Certificate, STP, comminuting/disinfecting system, and sewage holding tank. |
| Annex V | Garbage | Controls the discharge of shipboard garbage, plastics, food waste, cargo residues, incinerator ash, and related waste streams. | Garbage Management Plan, Garbage Record Book, placards, and HME cargo residues. |
| Annex VI | Air Pollution and Energy Efficiency | Controls SOx, NOx, PM, ODS, VOC, fuel oil quality, incinerators, EEDI, EEXI, CII, and SEEMP. | IAPP Certificate, IEE Certificate, BDN, fuel oil sampling, SEEMP, and CII rating. |
03 | Verification
The real risk often appears when documents, equipment, and operations do not match.
From a surveyor and PSC perspective, MARPOL compliance is not simply about whether equipment is installed. It is about whether the system is complete, records are reasonable, and discharge conditions match the trading area and operational context.
| Relevance | Annex | Typical Triggers | Ship Management / PSC Verification Focus |
|---|---|---|---|
| High | Annex I | Machinery-space oily water discharge, sludge handling, tanker tank washing, STS operations, and oil pollution incidents. | Whether the OWS operates properly, the 15 ppm alarm is effective, Oil Record Book entries match sludge/bilge quantities, and whether any bypass concern exists. |
| High | Annex II | Chemical tanker loading/discharging, tank washing, prewash, and NLS residue discharge. | Whether cargo categorization, the P&A Manual, prewash requirements, Cargo Record Book, and shore reception records are consistent. |
| Medium-High | Annex VI | Entering or leaving ECAs, fuel changeover, low-sulphur fuel, NOx controls, and energy efficiency ratings. | Whether BDNs, fuel oil sampling, sulphur content, IAPP/IEE, SEEMP, DCS, CII rating, and shipboard operations are consistent. |
| Medium | Annex V | Routine garbage handling, cargo residues, and HME determination for bulk carriers. | Garbage Record Book, Garbage Management Plan, placards, garbage categorization, and shore reception records. |
| Medium | Annex IV | Sewage discharge, STP failure, and use of sewage holding tanks. | ISPP, type approval of sewage treatment equipment, holding tank capacity, discharge valves, and operational records. |
| Medium | Annex III | Container ships, general cargo ships, and carriage of packaged dangerous goods or marine pollutants. | Whether dangerous goods declaration, labels, packaging, documents, stowage, and segregation comply with the IMDG Code. |
Practical reminder: Many MARPOL deficiencies are not caused by a complete absence of equipment, but by mismatches between certificate supplements, actual ship arrangement, piping routes, record book quantities, and real operations.
04 | Summary
Understand each Annex by asking what it controls, what is verified, and how it is implemented on board.
The following sections go through Annex I to Annex VI, preserving the chapter structure while translating it into language more useful for ship management and inspection.
Annex I｜Prevention of Pollution by Oil
Oil Pollution PreventionAnnex I is one of the core MARPOL annexes and among the most frequently verified on board. It covers machinery-space oily water, tanker cargo areas, oil residues, discharge controls, and oil pollution emergency response.
Chapter Breakdown
- Chapter 1:General provisions, definitions, application, exceptions, and equivalents.
- Chapter 2:Surveys and certification, corresponding to the IOPP Certificate.
- Chapter 3:Machinery spaces, covering bilge water, sludge/oil residues, OWS, 15 ppm alarm, and Oil Record Book Part I.
- Chapter 4:Tanker cargo areas, covering cargo tanks, slop tanks, ODME, COW, SBT, and Oil Record Book Part II.
- Chapter 5:Oil pollution emergency response, focusing on SOPEP, incident reporting, and shipboard response arrangements.
- Chapter 6:Shore reception facilities, requiring ports to receive sludge, oil residues, and oily water.
- Chapter 7:Special requirements for fixed or floating platforms.
- Chapter 8:Ship-to-ship transfer operations for oil tankers, linked to STS operation plans and operating requirements.
- Chapter 9:Restrictions on oil use and carriage in polar waters, including HFO-related requirements.
- Chapter 10:Verification of compliance, related to audits of Parties' implementation.
- Chapter 11:Polar Code provisions supplementing environmental requirements for polar-water operations.
Practical Focus
Verification usually looks beyond whether equipment is installed. It checks whether equipment, piping, tanks, certificates, Oil Record Books, and operational records are consistent.
Memory cue: Annex I = oily water, sludge/oil residues, tanker cargo areas, and SOPEP.
Annex II｜Noxious Liquid Substances in Bulk
Noxious Liquid Substances in BulkAnnex II mainly applies to chemical tankers or ships carrying noxious liquid substances in bulk. Its core logic is to classify cargoes by pollution hazard as Category X, Y, Z, or OS, and then determine prewash, discharge, and reception facility requirements.
Chapter Breakdown
- Chapter 1:General provisions, definitions, application, exceptions, and equivalents.
- Chapter 2:NLS categorization, establishing Category X / Y / Z / OS.
- Chapter 3:Surveys and certification, corresponding to the NLS Certificate.
- Chapter 4:Design, construction, arrangement, and equipment, including tanks, piping, pumps, stripping systems, and tank washing systems.
- Chapter 5:Discharge of NLS residues, regulating tank washings, residues, and discharge conditions.
- Chapter 6:PSC control, addressing port State verification of operational and discharge evidence.
- Chapter 7:Pollution emergency response, linked to SMPEP and incident response arrangements.
- Chapter 8:Shore reception facilities, ensuring ports can receive NLS residues and tank washings.
- Chapter 9:Verification of compliance, related to audits of Parties' implementation.
- Chapter 10:Polar Code provisions supplementing operational restrictions in polar waters.
Practical Focus
The focus is not simply whether discharge is allowed. It is whether cargo categorization, the P&A Manual, prewash, shore reception records, and Cargo Record Book form a consistent evidence chain.
Memory cue: Annex II = chemical cargo categorization plus tank washings / prewash management.
Annex III｜Harmful Substances in Packaged Form
Packaged harmful substancesAnnex III is used mainly together with the IMDG Code. It governs harmful substances carried in packaged form, identified as marine pollutants, or meeting the criteria in the Annex III appendix. The focus is packaging, marking, labelling, documentation, stowage, and quantity limitations.
Chapter Breakdown
- Chapter 1:General provisions covering packaging, marking, labelling, documentation, stowage, and quantity limitations.
- Chapter 2:Verification of compliance, related to Party implementation verification and audits.
- Appendix:Provides criteria for identifying harmful substances in packaged form.
Practical Focus
Unlike Annex I, Annex III does not primarily focus on extensive shipboard pollution prevention equipment. It focuses on the correctness of documentation, packaging, labelling, dangerous goods declaration, stowage, and segregation for harmful substances or marine pollutants.
Memory cue: Annex III = packaging, labels, declarations, stowage, and IMDG.
Annex IV｜Prevention of Pollution by Sewage from Ships
Ship SewageAnnex IV controls shipboard sewage, including sewage treatment equipment, holding tanks, discharge distance from land, navigation conditions, reception facilities, and certification requirements. It generally applies to ships of 400 GT and above engaged in international voyages, or ships certified to carry more than 15 persons.
Chapter Breakdown
- Chapter 1:General provisions defining sewage, applicable ships, and basic requirements.
- Chapter 2:Surveys and certification, corresponding to the ISPP Certificate.
- Chapter 3:Equipment and discharge controls covering STP, comminuting/disinfecting systems, sewage holding tanks, and distance-from-land/navigation conditions such as 3 nm and 12 nm.
- Chapter 4:Shore reception facilities requiring ports to provide sewage reception capacity.
- Chapter 5:PSC control, checking sewage equipment, certificates, and discharge arrangements.
- Chapter 6:Verification of compliance, related to audits of Parties' implementation.
- Chapter 7:Polar Code provisions supplementing sewage discharge restrictions in polar waters.
Practical Focus
Common inspection points include ISPP, sewage treatment plant nameplates, type approval, holding tank capacity, discharge valve position, distance-from-land conditions, and operational records.
Memory cue: Annex IV = STP, sewage holding tank, and discharge distance conditions.
Annex V｜Prevention of Pollution by Garbage from Ships
Ship GarbageAnnex V controls shipboard garbage. The basic principle is that the discharge of all garbage is prohibited unless expressly permitted by Annex V. Garbage includes food waste, domestic waste, operational waste, plastics, cargo residues, incinerator ash, cooking oil, fishing gear, animal carcasses, and more.
Chapter Breakdown
- Chapter 1:General provisions defining garbage, discharge conditions, prohibited items, placards, the Garbage Management Plan, and the Garbage Record Book.
- Chapter 2:Verification of compliance, covering Party implementation verification and audits.
- Chapter 3:Polar Code provisions adding garbage discharge restrictions in polar waters.
- Appendix I:Criteria for determining HME cargo residues.
- Appendix II:Garbage Record Book format.
Practical Focus
The easiest points to miss are garbage categorization and records, especially whether bulk carrier cargo residues are HME, which affects whether discharge is allowed or whether residues must be delivered to shore reception facilities.
Memory cue: Annex V = discharge is prohibited by default; exceptions must be expressly allowed.
Annex VI｜Prevention of Air Pollution from Ships
Air Pollution and Energy EfficiencyAnnex VI is currently the fastest-developing and most frequently updated Annex. It controls SOx, NOx, PM, ODS, VOC, shipboard incineration, fuel oil quality, and includes energy efficiency and carbon intensity requirements such as EEDI, SEEMP, EEXI, and CII in Chapter 4.
Chapter Breakdown
- Chapter 1:General provisions, definitions, application, exceptions, and equivalents.
- Chapter 2:Surveys, certification, and control methods, corresponding to IAPP, IEE, PSC, and fuel documentation verification.
- Chapter 3:Emission controls covering ODS, NOx, SOx / PM, VOC, shipboard incineration, and fuel oil quality.
- Chapter 4:Ship energy efficiency and carbon intensity rules covering EEDI, EEXI, SEEMP, IMO DCS, and CII rating.
- Chapter 5:Verification of compliance, related to Party implementation verification and IMO audits. The Net-Zero Framework remains a subsequent amendment topic under the draft revised Annex VI and should not be treated as a currently effective chapter.
Practical Focus
Annex VI is no longer only about exhaust emissions. It is a complete compliance system combining fuel oil sulphur content, NOx Tier, ECA requirements, BDNs, fuel sampling, IAPP, IEE, SEEMP, DCS, and CII.
Memory cue: Annex VI = air pollution, fuel oil, energy efficiency, and carbon intensity.
05 | Documents
Turning Annex requirements into document and equipment lists is the practical language of shipboard management.
On board, MARPOL ultimately appears as certificates, record books, equipment, plans, manuals, and shore reception records. The table below can be used as an initial checklist, but it does not replace flag State, Recognized Organization, or latest convention text requirements.
Certificates
Pollution Prevention Certificates
IOPP, NLS, ISPP, IAPP, IEE, and similar certificates are the first layer of evidence that a ship complies with the relevant Annex.
Record books
Operational Record Books
Oil Record Books, Cargo Record Books, Garbage Record Books, fuel changeover records, and similar records are among the most common materials used by PSC to trace operations.
Plans / Manuals
Plans and Manuals
SOPEP, SMPEP, P&A Manual, Garbage Management Plan, SEEMP, and similar documents translate rules into shipboard procedures.
| Annex | Main Certificates / Documents | Main Equipment / Systems | Verification Focus |
|---|---|---|---|
| Annex I | IOPP, Oil Record Book, SOPEP, STS Plan | OWS, 15 ppm alarm, ODME, sludge tank, standard discharge connection | Discharge records, sludge quantities, piping integrity, and bypass concerns. |
| Annex II | NLS Certificate, Cargo Record Book, P&A Manual, SMPEP | Stripping system, tank washing system, cargo piping / pumps | Cargo categorization, prewash, tank washing handling, and shore reception records. |
| Annex III | Dangerous goods declaration, IMDG documents, stowage plan | Packaging, labels, marks, and segregation arrangement | Whether documents, labels, packaging, and actual stowage are consistent. |
| Annex IV | ISPP Certificate, equipment data, operational records | STP, comminuting/disinfecting system, sewage holding tank | Equipment type approval, discharge valve control, holding tank capacity, and discharge conditions. |
| Annex V | Garbage Management Plan, Garbage Record Book, placards | Garbage categorization, storage, handling, and shore reception arrangements | Correct categorization, plastic discharge prohibition, HME determination, and reception facility records. |
| Annex VI | IAPP, IEE, BDN, SEEMP, DCS / CII data, NOx Technical File | Fuel oil system, main/auxiliary engine and boiler exhaust systems, incinerator, sampling points | Sulphur content, ECA fuel changeover, NOx Tier, fuel oil sampling, and CII rating. |
06 | Checklist
Read MARPOL like a surveyor: first check applicability, then consistency.
The following six steps can be used as a quick framework for ship management, internal audits, PSC preparation, or early-stage retrofit project screening.
01
Identify Ship Type and Trading Area First
Oil tankers, chemical tankers, container ships, bulk carriers, and passenger ships are subject to different Annexes and levels of verification.
02
Confirm Ship Certificates
Common certificates include IOPP, NLS, ISPP, IAPP, and IEE. Check certificate supplements and equipment lists as well.
03
Confirm Equipment Matches Certificates
Examples include OWS, ODME, STP, incinerator, fuel system, NOx-related equipment, and the Technical File.
04
Check Record Books for Reasonableness
Oil Record Book, Cargo Record Book, Garbage Record Book, BDNs, fuel changeover records, and CII / SEEMP data.
05
Check Special Areas and ECAs
Special Areas mainly appear under Annex I / II / IV / V. ECAs are Annex VI control areas for SOx, NOx, and PM. Both can change discharge or fuel requirements.
06
Confirm Shore Reception Records
Oil residues, garbage, sewage, and chemical residues often require shore reception facilities.
The Simplest Memory Map
Annex I
OilAnnex II
Bulk ChemicalAnnex III
Packaged GoodsAnnex IV
SewageAnnex V
GarbageAnnex VI
Air + GHG07 | Updates
Annex VI is currently the part that most needs continuous tracking.
MARPOL continues to evolve through IMO amendments and MEPC resolutions. The update notes below are current as of 2026-06-04. Practical application still depends on ship construction date, retrofit date, flag State requirements, and the latest convention text.
2022-11-01 / 2023-01-01
EEXI / CII Implementation Milestones
The relevant Annex VI amendments entered into force on 2022-11-01. From 2023-01-01, applicable ships began calculating EEXI and collecting data needed for annual operational CII and CII rating.
2025 · MEPC 83
Draft IMO Net-Zero Framework
MEPC 83 approved draft legal text intended for inclusion in the draft revised Annex VI. However, the subsequent adoption process has not been completed, so it should not be treated as currently effective requirements.
2026 · MEPC 84
Net-Zero Framework Deferred for Further Consideration
MEPC 84 agreed to establish an intersessional working group to build consensus on global measures. The second extraordinary session is expected to resume on 2026-12-04, subject to further IMO confirmation.
2026 · MEPC 84
North-East Atlantic ECA
MEPC 84 adopted the new North-East Atlantic ECA, expected to enter into force on 2027-09-01, with stricter NOx, SOx, and PM requirements applying from 2028.
Further confirmation required: For formal submissions, PSC preparation, fleet compliance assessment, or business decisions, always refer to the latest MARPOL text, IMO resolutions, flag State requirements, and Recognized Organization notices.