Lithium Batteries: Thermal Runaway and Fire Response on Board
Fires linked to lithium-ion batteries are growing sharply in maritime transport: understanding the thermal runaway phenomenon and response techniques is essential, since conventional extinguishers do not stop it.
Operational Explanation
Thermal runaway is an uncontrolled self-heating phenomenon that can occur in a damaged, overcharged or overheated lithium-ion battery, with internal temperatures that can exceed 300°C, generating flammable gases and spreading rapidly to adjacent cells. Unlike a conventional fire, thermal runaway does not stop simply by cooling the external surface: the internal chemical reaction continues to feed itself.
The spread of containers carrying electric vehicles, Battery Energy Storage Systems (BESS) and battery-powered devices has made this risk one of the leading causes of fires on board container ships in recent years, often in combination with mis-declared or poorly secured cargo.
Amendment 43-26 update: the CCC Sub-Committee, at its 11th session, and the E&T 43 editorial and technical group agreed substantial changes to the carriage of vehicles, including those with conventional fuels, hybrids and lithium batteries: a new Special Provision SP980 and updates to provisions SP961 and SP962, designed to make the classification of battery-powered vehicles clearer and safer compared with the framework already introduced by Amendment 42-24. This level of detail adds to, without overlapping, the new general UN entries for battery-powered vehicles already introduced by the 2024 edition of the Code.
Regulatory Reference
The IMDG Code (Amendment 42-24) governs the classification of lithium batteries (Class 9) and introduces new entries for sodium-ion batteries and battery-powered vehicles; the updated EmS Guide provides specific emergency procedures for lithium battery fires. Amendment 43-26 (adopted at MSC 111, May 2026, voluntary application from 2027, mandatory from 2028): new SP980 and updates to SP961/SP962 for the carriage of battery-powered vehicles. There is not yet a single, binding IMO standard for extinguishing thermal runaway on board, but P&I and manufacturer guidance recommend specific approaches.
Scope of Application
All ships carrying containers with lithium batteries, electric vehicles or energy storage systems, with particular attention to firefighting crew training on the specific features of this type of ignition source compared with conventional fires.
Procedure / How to Complete It
- Check the correct classification and securing of units containing lithium batteries before loading, in accordance with the CTU Code.
- If early warning signs are detected (smoke, abnormal heat, acrid odour) from a container with batteries, isolate the area and immediately notify the Master.
- Apply the massive water-cooling strategy to contain propagation to adjacent cells, without expecting it to extinguish the internal chemical reaction.
- Avoid opening the affected container directly until it is certain that the thermal runaway reaction has burned itself out, due to the risk of reignition and the release of toxic gases.
- Document the event and conduct a post-emergency debrief to check the effectiveness of the response and update the SMS procedures accordingly.
Practical Example
Example: a container with a damaged Battery Energy Storage System (BESS) generates smoke and abnormal heat during transport; the crew applies continuous massive cooling with seawater to the outside of the container for hours, without attempting to open it directly, until the reaction has completely burned itself out.
Real Cases
Common Mistakes Mistake Library
| Mistake | Consequence | How to avoid it |
|---|---|---|
| Treating a lithium battery fire with the same techniques as a conventional fire | Ineffective extinguishing and risk of reignition after an apparent shutdown | Train the crew specifically on the prolonged massive-cooling strategy, not simple extinguishing |
| Premature opening of the affected container to check its internal condition | Exposure to toxic gases and risk of sudden reignition | Wait until it is certain the reaction has burned out before any opening, in accordance with the updated EmS procedures |
| Cargo securing not specifically checked for heavy units such as BESS | Cargo shift in heavy weather, with risk of structural ignition | Apply reinforced lashing checks for high-risk units such as batteries and storage systems |
PSC Observations
Operational Tips
- Include specific thermal runaway scenarios in periodic fire drills, explicitly distinguishing them from conventional fires.
- Do not rely on conventional portable extinguishers as a definitive measure against a lithium battery ignition inside a closed container.
- Check that crew training is up to date with the latest editions of the EmS Guide, which reflect the growing prevalence of this type of cargo.
Checklist
- Specific crew training on thermal runaway and differences from conventional fires
- Prolonged massive-cooling procedure defined in the SMS
- Reinforced lashing check for units containing batteries/BESS
- Updated EmS Guide available and used in periodic drills
- Post-emergency debrief procedure for lithium battery events