Specialized EV Fire Tools Ineffective Against Thermal Runaway, Study Finds
Research from the UL Fire Safety Research Institute reveals that traditional water remains the only viable tool for controlling EV flames, despite its inability to stop internal chemical reactions.
A comprehensive study by the UL Research Institutes’ Fire Safety Research Institute (FSRI) has found that specialized tools designed to fight electric vehicle (EV) fires are largely ineffective compared to traditional water-based suppression. The findings suggest that current industry innovations fail to significantly outperform the use of massive quantities of water when managing lithium-ion battery fires.
The FSRI reached these conclusions after analyzing 18 experimental burns, which included 15 electric vehicles and three internal combustion engine vehicles. The research confirms that while water is the most effective tool for quenching visible flames and cooling the battery enclosure, it is powerless to stop the internal chemical process of thermal runaway once it has started. According to the report authors, applying copious amounts of water to the battery enclosure is wasteful and will not stop this internal reaction.
The Challenge of Thermal Runaway
As electric vehicles have captured a larger share of the automotive market, emergency responders have faced unique challenges stemming from lithium-ion battery chemistry. Unlike traditional gasoline fires, EV fires are driven by thermal runaway—an accelerating, self-heating chain reaction within the battery cells. This process makes EV fires significantly more difficult to extinguish than those in internal combustion engine vehicles, as the fire is fueled by the battery's own internal chemistry rather than an external fuel source.
To combat this, various industry solutions have been marketed to fire departments, including specialized chemical additives, submersion containers, and vehicle blankets. However, the FSRI study indicates these tools do not provide a meaningful advantage over water in controlling the scale of the incident.
Infrastructure and Resource Risks
These findings reveal a critical gap in emergency response capabilities as the global EV fleet grows. The reliance on water is problematic because of the extreme volumes required to manage large-scale battery fires. For example, a Tesla Semi fire in California required approximately 50,000 gallons of water to extinguish, illustrating the immense resource drain a single incident can impose on local services.
If specialized tools remain ineffective and traditional methods require such extreme volumes, urban firefighting infrastructure may be ill-equipped for the scale of potential EV incidents. This deficiency could lead to prolonged road closures, higher resource consumption, and increased risk to first responders.
Future Outlook
Moving forward, the industry must address the reality that current suppression tactics only manage the symptoms of a battery fire rather than the cause. While water remains the primary tool for cooling and visibility, the internal chemical process of thermal runaway remains an unsolved challenge for emergency services. Fire departments will likely need to re-evaluate their procurement of specialized equipment in favor of strategies that account for the extreme water requirements of large-scale EV fires.