Incinerator Operations
What can be incinerated on board, where it's prohibited, and how to keep track of the ash produced.
Operational Explanation
On-board incineration reduces the volume of solid waste and sludge, but is subject to precise restrictions on what may be incinerated, where, and how the resulting ash must be managed.
There is no MARPOL ban on incinerating in port
Regulation 16 of Annex VI, in the version of resolution MEPC.328(76), limits incineration by substance (16.2 and 16.3) and by equipment (16.1: “Except as provided in paragraph 4 of this regulation, shipboard incineration shall be allowed only in a shipboard incinerator”). The only geographical limit is 16.4, and it has to be read whole: “Shipboard incineration of sewage sludge and sludge oil generated during normal operation of a ship may also take place in the main or auxiliary power plant or boilers, but in those cases, shall not take place inside ports, harbours or estuaries”.
The grammatical subject is incineration in the main or auxiliary power plant or boilers, and the phrase “in those cases” ties the prohibition to that hypothesis alone. 16.4 is a derogation from 16.1: it allows sludge and sludge oil to be burned outside the incinerator, and in exchange imposes the port limit. Anyone using the approved incinerator is untouched by that sentence.
This does not mean the incinerator may be lit anywhere. It means that the prohibition, where it exists, has another source: it is national, sub-national or port-level. Two documented examples. California prohibits onboard incineration within three miles of its coast (17 CCR §93119): “no cruise ship or oceangoing ship owner or operator … shall conduct onboard incineration within three miles of the California coast, except when required to be operated under the direction or supervision of the United States Coast Guard”. The Port of Rotterdam by-laws are blunter still (Port By-Laws 2020, art. 4.1): “It is prohibited … to use a waste incinerator on board a vessel in the port”. The practical difference is this: the confirmation to ask the bridge for is not “are we in port?” but “which jurisdiction are we in, and what do its rules say?”.
Regulatory Reference
MARPOL Annex VI, Regulation 16. Prohibited from incineration: cargo residues subject to Annex I/II/III and contaminated packing materials, PCBs, waste containing more than traces of heavy metals, refined petroleum products containing halogen compounds, sewage sludge and sludge oil not generated on board, exhaust gas cleaning residues. PVC has its own regime (Reg. 16.3): prohibited except in incinerators holding an IMO Type Approval Certificate. Sludge and sludge oil generated during normal operations may be incinerated in the main or auxiliary power plant or boilers, but not inside ports, harbours and estuaries (Reg. 16.4).
The temperatures are the operational part of the Regulation, and they sit in two different places. Regulation 16.9 holds the operating thresholds, and they distinguish the two types of unit: in continuous-feed incinerators “waste shall not be fed into the unit when the combustion chamber gas outlet temperature is below 850°C” — a prohibition on feeding, not merely a reference value; in batch-loaded ones the unit must be designed so that the gas outlet temperature reaches 600 °C within five minutes of start-up and thereafter stabilises at not less than 850 °C. The same 16.9 requires the temperature to be monitored at all times the unit is in operation.
The 850-1,200 °C range often quoted is not in Regulation 16: it is in Appendix IV to Annex VI, among the operating limits the unit must meet for its type approval, together with oxygen in the combustion chamber between 6 and 12%, carbon monoxide in flue gas at a maximum average of 200 mg/MJ, a maximum average soot number of Bacharach 3 or Ringelman 1, and unburned components in ash residues at no more than 10% by weight. The same values appear in the standard specification, resolution MEPC.244(66).
Two documentary duties complete the picture: Regulation 16.7 requires the unit to carry the manufacturer's operating manual, retained with the unit, specifying how to operate within the Appendix IV limits; and 16.8 requires the personnel operating it to be trained to apply that manual. The IMO type approval certificate records, among other things, the average flue gas outlet temperature: it is the document against which the figures measured on board are checked.
Scope of Application
Every ship fitted with an incinerator approved under MEPC.244(66) or an equivalent standard.
Procedure / How to Complete It
- Verify that the waste to be incinerated does not fall into a prohibited category.
- Check the jurisdiction the ship is in and the rules that apply there before start-up. MARPOL does not prohibit the use of the approved incinerator in port; the prohibitions are national, sub-national or port-level, and they change from call to call. The MARPOL prohibition in 16.4 covers the other thing: burning sludge and sludge oil in the main or auxiliary power plant or boilers, which is not done inside ports, harbours or estuaries.
- Record the operation where the material requires, not in a single register: incineration of waste subject to Annex V goes in the Garbage Record Book, with the particulars required by the applicable format; burning of oil residues (sludge) goes in the Oil Record Book Part I, code C and the applicable item. Other operational logs are kept only where the approved manual, the SMS, the flag or a local rule requires them.
- Handle incinerator ashes as a category of garbage and record in the Garbage Record Book the operations the applicable format provides for — in particular landings ashore and the relevant incinerations. The GRB records operations, not quantities generated.
- Periodically check the combustion temperature and maintenance per the manufacturer's specification.
Practical Example
The Garbage Record Book form — Appendix II of Annex V, res. MEPC.201(62), now superseded by the form of res. MEPC.277(70) — asks for the estimated amount in cubic metres, not in kilograms; and for a delivery to a reception facility the position column carries the port or facility, not a position under way, which belongs to discharge-to-sea or incineration entries.
The correct entry separates two distinct operations, each on its own row. The incineration: date and time, two positions of the ship — at the start and at the stop of incineration, category of waste burned, estimated amount in m³ in the Incineration column, signature. The landing of the resulting ash: date, port or facility — “Trieste, facility X” — category “Incinerator ashes”, estimated amount in m³ in the To Reception Facility or Ship column, signature, and the facility's receipt kept with the book.
On which form, though. Until now this page anchored the Garbage Record Book form to res. MEPC.201(62), in force since 1 January 2013. The two-part form does not come from there: it comes from res. MEPC.277(70), in force since 1 March 2018. Part I applies to all ships and covers categories A to I; Part II applies only to ships carrying solid bulk cargoes, with J Cargo residues (non-HME) and K Cargo residues (HME).
And it is not merely a date. The two resolutions assign different letters to the same categories. In the single form of MEPC.201(62), cargo residues were G, animal carcasses H, fishing gear I. In Part I of MEPC.277(70), F is operational wastes, G animal carcasses, H fishing gear and I e-waste. Anyone following a page anchored to the older resolution records cargo residues under G, when G today is animal carcasses: the wrong citation does not stay on paper, it produces a wrong entry. Incinerator ashes are category E — Incinerator ashes of Part I, in both versions.
On the date format: the Appendix II form prescribes none, and we say so because we expected otherwise. The practical advice stands, though: use an unambiguous one. “21.07.2026” reads unambiguously only because 21 cannot be a month, whereas “07.06.2026” read by an inspector used to month-first order becomes a different date.
What Typically Goes Wrong
Common Mistakes Mistake Library
| Mistake | Consequence | How to avoid it |
|---|---|---|
| Incineration in port treated as an Annex VI violation | People look in MARPOL for a prohibition that is not there and lose sight of what actually matters: the port's or coastal State's own rules, which vary from call to call and are the source of the actual penalties | Bridge-engine room coordination before every start-up, asking the right question: not “are we in port?” but “which local rules apply here?” |
| Incineration of prohibited waste (e.g. PVC) | Serious violation, environmental damage | Crew training on prohibited categories |
| Ash not recorded in the Garbage Record Book | Inconsistency between waste produced and disposed of | Systematic recording of ash as a dedicated category |
What the PSCO Checks
Operational Tips
- Set an internal procedure requiring bridge confirmation before start-up — not on the question “are we in port?”, but on the jurisdiction and the applicable local rules. Keep a list of the regular calls with each one's incineration rule on board: it is the only way to answer in time.
- Train the crew on the waste categories prohibited from incineration.
- For sludge oil use the Oil Record Book, not the Garbage Record Book as a substitute register: the documentary route must stay consistent with the material incinerated.
Preparation checklist
Educational checklist. This summary supports learning and preparation only. It does not replace the vessel’s approved procedures, manuals, statutory documents, company SMS, or applicable official requirements. Completing it demonstrates neither compliance nor readiness for an inspection: it shows that a list has been read, not that the ship is in order. Always verify the current documents carried on board.
- Local rules of the call verified before start-up (MARPOL sets no general in-port prohibition: the prohibitions are national or port-level)
- If burning sludge or sludge oil in the main or auxiliary power plant or boilers: ship outside ports, harbours and estuaries (Reg. 16.4)
- Waste verified as not prohibited
- Combustion temperature and parameters within range
- Ash recorded in the Garbage Record Book
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Last substantive revision of this page: 28 August 2026 · page fingerprint 47cc97c4dd11