Which Rulebook Governs an EV Fire at Sea?

Four IMO instruments touch a vehicle-deck fire and none owns it. SOLAS II-2 sets the detection, ventilation and suppression the ship must carry. The IMDG Code classifies the vehicle, then exempts it on a ro-ro. The ISM Code makes the operator write the procedures. MARPOL sets what may go over the side and rarely reaches a fire. The losses happen in the gaps.

This matters because 'compliant' is only a meaningful word when it names the instrument. A port-state deficiency is written under one code, a class condition under another, a charterparty warranty under a third, and a P&I claim is argued across all of them. An owner specifying a detection retrofit, and an underwriter reading the submission that describes it, both need to know which rulebook a given sentence is answering — because a ship can satisfy SOLAS to the letter while the ISM-governed configuration of the same equipment leaves the deck unwatched. Every casualty anatomy on this site has that shape.

SOLAS: the ship

SOLAS governs what the ship must be fitted with and have certified — not how the crew runs it. Chapter II-2 is the fire chapter: Regulation 20 covers vehicle, special category and ro-ro spaces (permanent ventilation independent of other spaces, a fixed fire detection and alarm system, a fixed fire-extinguishing system), and Regulation 19 covers the carriage of dangerous goods. Two other SOLAS chapters are the hinges on which the rest of the map turns: Chapter VII makes the IMDG Code mandatory, and Chapter IX makes the ISM Code mandatory. The 2026 amendments in MSC.550(108) added weather-deck detection, water monitors, alarm-presentation and loading-mode provisions — for passenger ships built from 1 January 2026; a cargo ship such as a PCTC received one detection paragraph, 20.4.1.5.

What SOLAS does not do is reach the operating state of what it mandates. It requires the detection system; the FSS Code that sits under it lets smoke sections be disconnected during loading; neither says what the timer should be set to or which decks are patrolled meanwhile. It requires a drencher; it does not say whether the pump's valve control is in 'auto' on the night. Those are ISM questions, and the two instruments are read together far less often than they should be.

IMDG: the cargo — and the exemption

The IMDG Code is the rulebook that classifies an electric vehicle as dangerous goods and then, on a ro-ro, sets most of itself aside. Mandatory under SOLAS Chapter VII since 1 January 2004 and amended on a two-year cycle, it moved lithium-battery vehicles from the generic UN 3171 to UN 3556 in Amendment 42-24, mandatory from 1 January 2026. But Special Provision 961 relieves vehicles carried in flag-approved vehicle spaces of the Code's packing, marking, documentation and stowage requirements, which is why a ro-ro deck receives no chemistry, no state of charge and no damage history with the car. Amendment 43-26 begins to close that gap: new SP 980 requires consignors to assess a vehicle's safety condition before offering it, and the SP 961 exemption is tied to SOLAS II-2/20 approved spaces, so a car in a container stack loses it from 2028.

IMDG is also the only place MARPOL gets a foothold on a vehicle deck. MARPOL Annex III, on harmful substances carried in packaged form, is implemented through the IMDG Code's marine-pollutant provisions — so a declared pollutant in packaged form is a MARPOL matter, while a vehicle exempted under SP 961 is neither.

ISM: the procedures

The ISM Code is where SOLAS hardware becomes a practice, and it is the instrument most casualty reports end up citing. Mandatory since 1 July 1998 through SOLAS Chapter IX, it requires each company to run a documented safety management system, audited to a Document of Compliance ashore and a Safety Management Certificate aboard. Three of its sections carry the vehicle-deck fire problem. Section 8 (emergency preparedness) requires the company to 'identify potential emergency shipboard situations, and establish procedures to respond to them', with drills. Section 10.3 requires it to 'identify equipment and technical systems the sudden operational failure of which may result in hazardous situations' and to test stand-by arrangements that are not in continuous use. Section 9 requires non-conformities and hazardous occurrences to be reported, investigated and analysed.

Map those onto the record. The Lisco Gloria's drencher pump valve control in 'manual' is a Section 10.3 critical-equipment failure; the BSU's recommendation that crews report malfunctions immediately and that resolved defects be rechecked at ISM audit is Section 9. The loading-phase detection state — which sections are muted, for how long, what patrols the deck — is a Section 8 procedure or it is nothing. And the IMO interim guidelines in MSC.1/Circ.1615 and EMSA's guidance on alternative-fuel vehicles both ask a ro-pax operator to run its EV charging, state-of-charge and stowage policy as an ISM risk assessment rather than wait for a SOLAS rule. When a submission says 'compliant', the ISM question is the sharper one: show the procedure.

MARPOL: the one that mostly isn't there

MARPOL is the instrument people expect to govern a burning ship's runoff, and it largely does not. Its six annexes cover oil, noxious liquids in bulk, harmful substances in packaged form, sewage, garbage and air pollution. A vehicle-deck fire produces none of those as a regulated discharge: the firefighting water carrying battery electrolyte, metals and foam over the side is not one of MARPOL's regulated operational discharges, and the bunker fuel that escapes when a hull is breached becomes an Annex I event only in the sense that any spill is. What actually governs pollution from a casualty is coastal-state law at the scene and the liability conventions afterwards — the Bunkers Convention for fuel, the Nairobi Convention for the wreck. The BSU's observation on the Lisco Gloria that 'the marine environment was marginally impaired' is a casualty-investigation finding, not a MARPOL one. The 2026 restrictions on PFOS firefighting foam come from the Stockholm Convention and EU regulation, not from MARPOL either.

The others: STCW, the CSS Code, class and guidance

Around the four conventions sit the instruments that decide whether the hardware and procedures work on the night. STCW Table A-VI/3 sets the competence for officers who control firefighting: four competences — controlling operations, organising fire parties, inspecting and servicing detection and extinguishing systems, and investigating fire incidents — with refresher training every five years. The CSS Code's Annex 4 governs the securing of wheel-based cargo, which is the constraint any deck-mounted detection layer must respect without touching a lashing. Classification society notations go beyond SOLAS on request, and a charterer or underwriter can make them contractual. And a layer of guidance with no legal force but real market weight — MSC.1/Circ.1615, EMSA's AFV guidance, the VCSF guidelines, IUMI's EV best-practice paper — is what a ship is actually measured against once a claim is in dispute.

What it means for owners and underwriters

Ask compliance questions by instrument, not in general. To SOLAS: what is fitted and certified, and under which paragraph — a PCTC's answer for detection is 20.4.1.5 and the FSS Code, nothing more. To IMDG: what was declared, which on a ro-ro under SP 961 is usually nothing, so the ship's own screening is the only cargo knowledge it has. To ISM: show the Section 8 procedure for a vehicle-deck fire and the Section 10.3 critical-equipment list, and check that the drencher pump, its valve line-up and the detection system's loading configuration are on it.

To MARPOL: nothing on the fire itself — plan runoff and foam under local law and the liability conventions instead. To class and guidance: which notations are held and which voluntary standards the charterparty or the policy has made binding. A detection layer lives in two of these at once — as SOLAS equipment and as an ISM configuration — and the distance between 'we were compliant' and 'the drencher was in manual' is exactly the distance between those two.

Sources

• 1. IMO — SOLAS Chapter II-2 Regulations 19 and 20 (carriage of dangerous goods; protection of vehicle, special category and ro-ro spaces), as amended by Resolution MSC.550(108), adopted 23 May 2024, in force 1 January 2026; SOLAS Chapter VII (carriage of dangerous goods) and Chapter IX (management for the safe operation of ships).
• 2. IMO — 'Carriage of dangerous goods' (imo.org): the IMDG Code given mandatory status under SOLAS from 1 January 2004; amendments on a two-year cycle; the provisions of MARPOL Annex III 'also extended in the IMDG Code'.
• 3. IMO — IMDG Code Amendment 42-24 (Resolution MSC.556(108), mandatory 1 January 2026): UN 3556 for lithium-ion battery-powered vehicles; Special Provision 961 exemption for vehicles in flag-approved vehicle spaces; Amendment 43-26 (SP 980; SP 961 tied to SOLAS II-2/20 approved spaces).
• 4. IMO — 'ISM Code' (imo.org): adopted by Resolution A.741(18) in 1993; mandatory through SOLAS Chapter IX from 1 July 1998; and the International Safety Management Code, Sections 8 (emergency preparedness), 9 (reports and analysis of non-conformities, accidents and hazardous occurrences) and 10.3 (critical equipment and technical systems).
• 5. IMO — 'International Convention for the Prevention of Pollution from Ships (MARPOL)' (imo.org): Annexes I–VI and their scope; Annex III, harmful substances carried by sea in packaged form, in force 1 July 1992.
• 6. IMO — STCW Code, Table A-VI/3, specification of minimum standard of competence in advanced fire fighting (control of fire-fighting operations; organising and training fire parties; inspecting and servicing fire detection and extinguishing systems; investigating and reporting fire incidents); refresher training at intervals not exceeding five years.
• 7. IMO — Code of Safe Practice for Cargo Stowage and Securing (CSS Code), Resolution A.714(17), Annex 4: safe stowage and securing of wheel-based (rolling) cargoes.
• 8. IMO — MSC.1/Circ.1615, Interim guidelines for minimizing the incidence and consequences of fires in ro-ro spaces and special category spaces of new and existing ro-ro passenger ships; EMSA — Guidance on the carriage of alternative fuel vehicles in ro-ro spaces.
• 9. Bundesstelle für Seeunfalluntersuchung — Investigation Report 445/10, Lisco Gloria (2012): drencher pump valve control; recommendation on reporting malfunctions and rechecking at ISM audit; environmental finding.