Change Over Fuel (Fuel Oil Changeover ECA)
Separate fuels, already-compliant fuel or approved equivalents: plan ECA transitions and record relevant events.
Operational Explanation
Entering a SOx/PM ECA requires fuel within 0.10% m/m or an applicable approved equivalent method. An actual changeover is required only when separate fuels are used for compliance: a ship always using compliant fuel need not switch.
The Mediterranean 0.10% SOx/PM limit applies from 1 May 2025 (MEPC.361(79)). Plan entry compliance, not an obligatory switch regardless of the fuel already in use.
2026 update: two new ECAs were designated (Canadian Arctic and the Norwegian Sea, Resolution MEPC.392(82), from 1 March 2026), adding to North America, the US Caribbean, the Baltic, the North Sea and the Mediterranean. For the full regulatory picture, see the MARPOL Annex VI topic.
Regulatory Reference
MARPOL Annex VI, Regulation 14 (sulphur limits) and Regulation 4 (equivalent methods, e.g. scrubbers). Global sulphur cap 0.50% m/m since 2020; ECA limit 0.10% m/m.
The provision this page rests on is Regulation 14.6. In the revised Annex VI (res. MEPC.328(76)) it reads: “Those ships using separate fuel oils to comply with paragraph 4 of this regulation and entering or leaving an emission control area set forth in paragraph 3 of this regulation shall carry a written procedure showing how the fuel oil changeover is to be done, allowing sufficient time for the fuel oil service system to be fully flushed of all fuel oils exceeding the applicable sulphur content specified in paragraph 4 of this regulation prior to entry into an emission control area. The volume of low sulphur fuel oils in each tank as well as the date, time and position of the ship when any fuel oil changeover operation is completed prior to the entry into an emission control area or commenced after exit from such an area shall be recorded in such logbook or electronic record book as prescribed by the Administration”.
Regulation 14.6 requires a written procedure and records for ships using separate fuels. Compare tank volumes with times, positions and operating data: the declared volume alone does not demonstrate that the system has been fully flushed.
Regulation 14.7 exempts 14.4/14.6 requirements during the first twelve months after designation enters into force: Canadian Arctic and Norwegian Sea, 1 March 2026 → SOx/PM limits 1 March 2027. The NOx timetable is separate.
Where fuel is unavailable, 18.2 requires evidence of purchase attempts consistent with the voyage and alternative sourcing, plus notification to flag and the competent destination-port authority. The FONAR, model in MEPC.320(74), records voyage, suppliers, constraints, sourcing plans and FONARs in the previous twelve months; it does not automatically authorize non-compliance. The authority considers all circumstances, including the indication against undue deviation or delay; national implementation effects cannot be resolved simply by contrasting “should” and “shall”.
For future planning, IMO has adopted the North-East Atlantic ECA: entry into force is scheduled for 1 September 2027 and the SOx/PM requirement from 1 September 2028. IMO MEPC 84.
Scope of Application
Ships that, in order to comply with the ECA sulphur limit, use separate fuel oils: these are the ships Regulation 14.6 asks for a written changeover procedure and the related records. The compliance method has to be settled first: a ship running continuously on a single already-compliant fuel performs no changeover, and a ship covered by an equivalent arrangement approved under Regulation 4 — scrubber, alternative fuels — follows that, not this procedure.
Procedure / How to Complete It
- Establish the method and whether switching is needed: separate fuels, one compliant fuel or an approved equivalent. Identify all consumers and actual boundaries/dates.
- For separate fuels follow the written procedure and manuals: compatibility, temperature/viscosity, whole-system volumes, recirculation, mixing/flushing, pumps and filters. Do not use universal times or gradients.
- Complete flushing and system compliance before entry. Monitor the transition; follow the safe procedure and reassess the navigation plan if abnormalities occur instead of forcing the change.
- Record low-sulphur volumes in each tank, date, time and position on completion before entry and commencement after exit, if switching occurs. Use the Administration-prescribed record.
- For an approved equivalent check consumer coverage, operation, records and local EGCS restrictions. Leaving an ECA does not require abandoning cleaner fuel.
Practical Example
Training example for the North Sea ECA: its boundary includes the English Channel and approaches east of 5° W and north of 48°30′ N. The system must comply before crossing the boundary, not merely before reaching port.
03 AUG 2026: start 04:00 UTC, 49°20′ N 006°10′ W; completion 06:30 UTC, 49°28′ N 005°35′ W, still outside the area. Illustrative completion volumes: service tank 1, 12 m³; settling tank 1, 25 m³; storage tank 2P, 80 m³. The actual entry must include every relevant tank. The BDN and statutory sample document the batch where required; a commercial report alone does not prove that the entire mixed circuit is already compliant.
What Typically Goes Wrong
Common Mistakes Mistake Library
Avoid calculating one pipe instead of the system, omitting compatibility/viscosity checks, completing after the boundary, missing tank volumes, treating FONAR as permission, or converting two geographical transitions into two necessarily mandatory fuel changes.
What the PSCO Checks
Operational Tips
- Prepare margin and technical checks for all consumers.
- Use the prescribed record, with an SMS supporting form if appropriate.
- Separate SOx/PM and NOx dates; stricter company choices remain possible.
- Document unavailability and notify flag and destination.
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.
- Need for switching and compliance method established
- Compatibility, temperature/viscosity and recirculation checked against manuals
- All consumers compliant before entry; abnormalities monitored
- 14.6 events recorded with tank volumes, date/time/position
- BDN/samples retained where required; equivalence and local restrictions checked
FAQ
Related Topics
Last substantive revision of this page: 15 September 2026 · page fingerprint 71b7afcd4472