In the first part of this series, we explained why EV fires differ from fires involving internal combustion vehicles and why this topic has been receiving increasing attention. We also showed that fire blankets play an important role in the initial phase of response, particularly in the rapid stabilization of the situation.
With electric vehicles, however, the suppression of visible flames often does not mean that the incident has been fully resolved. On the contrary, once the first phase of the response is completed, additional challenges emerge that are not immediately visible but have a significant impact on the safety of subsequent actions.
Flames do not mean the fire is over
In conventional vehicle fires, the disappearance of flames is in most cases considered a clear indication that the incident is under control. With EV fires, this assumption often does not apply.
If a lithium-ion traction battery is damaged and thermal runaway is initiated, the process may continue even after flames have been suppressed externally. Chemical reactions and heat generation can persist inside the battery module, without immediate external signs.
From a response perspective, this means that an electric vehicle fire cannot be assessed solely based on the visibility of flames.
Persistent temperatures and the risk of re-ignition
One of the main challenges after flame suppression is persistently high temperatures within the battery. Battery modules are enclosed and structurally protected, which significantly limits natural heat dissipation.
Even after the situation appears stabilized:
the battery may remain extremely hot
heat can continue to propagate between cells
the risk of re-ignition may persist
Re-ignition can occur with a time delay, for example during vehicle relocation, changes in position, or handling after the initial response.
Toxic gases and secondary impacts of EV fires
Another risk that often becomes apparent only after flames are suppressed is the release of toxic and irritating gases. These gases may be emitted even in the absence of open flames and pose a particular risk in enclosed spaces.
In parking garages, industrial halls, or other enclosed facilities, an EV fire can therefore lead to:
restricted or closed access to the area
evacuation of occupants
the need for extended ventilation and environmental monitoring
In addition, operational and logistical consequences arise, as the vehicle may need to be monitored for an extended period and secured against further risk.
EV fires therefore cannot be treated as a single, short-term event that ends once flames are no longer visible. After the initial phase of the response, open questions remain regarding battery temperature, the risk of re-ignition, and the safety of further handling of the vehicle.
These factors highlight the need to approach EV fires in a systematic way, which will be the focus of the third part of this series.
