- Full-scale tests highlight thermal runaway, toxic exposure and fire blanket risks for firefighters.
- Water remains the key suppression tool, while thermal runaway may continue.
- Toxic exposure and reignition risks persist, requiring PPE and SCBA throughout the incident.
The Fire Safety Research Institute (FSRI), part of UL Research Institutes, has published Full-Scale Electric Vehicle Fire Experiments and Recommendations for Fire Incident Response, based on 18 full-scale vehicle fire experiments.
The research compared EV fires with internal combustion engine vehicle fires and tested different suppression methods, including water, EV fire blankets and water combined with an additional suppression agent.
Nine vehicles were allowed to burn without suppression, while a further nine were used to assess suppression techniques. The EVs were fully charged before battery fires were initiated and allowed to develop for six minutes before suppression began, reflecting standard response times in North America.
The free-burn tests found that EV and conventional vehicle fires showed similar fire growth rates, peak fire sizes and overall fire durations. EVs released more total energy on average, which researchers attributed to their greater vehicle mass.
The research found that water can be used to suppress cabin fires, protect nearby exposures and control flaming associated with thermal runaway while the battery burns itself out.
None of the suppression techniques tested stopped thermal runaway once it had begun, while adding a suppression agent to water provided no greater effectiveness than water alone.
The report does not recommend attempting to directly extinguish or cool the battery, as vehicle construction prevents firefighters from effectively reaching the battery pack.
Researchers also warned that EV fire blankets can create an explosion hazard if flammable gases accumulate beneath the blanket or in confined environments. Blankets should not be repositioned once deployed and should not be used indoors or in confined spaces.
Firefighters should remain in full PPE and SCBA throughout the incident, including overhaul, because of persistent toxic exposure and reignition risks.
Researchers found elevated concentrations of metals and particulate fluoride in smoke, suppression runoff water and contaminated turnout gear associated with battery fires.
For Middle East fire services, the research offers an evidence-based reference point as they consider how existing vehicle-fire tactics can be applied to EV incidents. While the experiments were based on a North American response scenario, the central findings point to a pragmatic approach: familiar firefighting tools remain effective for controlling the immediate fire, but battery involvement demands particular attention to thermal runaway, toxic exposure, reignition and the limitations of certain suppression techniques.
