Electric Vehicle (EV) Fires: Best Practices and Response Strategies

Electric vehicles (EVs) present distinct challenges in fire safety, primarily due to their lithium-ion battery systems. While these batteries are highly efficient and powerful, they can pose significant risks when involved in a fire. Traditional firefighting techniques, which rely on disrupting one of the elements of the fire triangle (heat, fuel, or oxygen), are often ineffective and may even worsen the situation when applied to lithium-ion battery (LIB) fires.

Even after a LIB fire appears extinguished, the battery can remain in a state of thermal runaway, continuing to release flammable and potentially explosive vapours. This critical risk must be taken into account during all stages of EV fire response. The use of specialised equipment and a strategic, informed approach is essential to ensure both safety and effectiveness.

Below is a comprehensive guide to best practices for managing electric vehicle fire incidents.

1. Early Detection and Prevention

Off-Gassing Recognition

Early detection is paramount. If an EV emits a chemical odour, hissing sounds, or visible smoke, it may be off-gassing—a sign of potential thermal runaway. Identifying and acting on these early warning indicators can prevent a full-scale fire. The vapours released during this phase are highly flammable and may be explosive; this risk should be clearly considered to protect both people and property.

Preventive Measures

Battery Management Systems (BMS): A functioning BMS monitors battery health and can alert the driver to conditions that could lead to a thermal event.

Routine Maintenance: Regular inspection of battery systems and associated components helps identify and address potential issues before they escalate.

2. Immediate Actions During an Incident

Ensure Personal Safety

Evacuate the Area: Immediately remove occupants from the vehicle and establish a safety perimeter to protect bystanders.

Alert Authorities: Contact emergency services without delay. Inform them that the incident involves an electric vehicle to ensure an appropriate and timely response.

Initial Containment (If Safe to Do So)

Vehicle Fire Blanket: If the fire is in its early stages and it is safe to approach, trained personnel may deploy a fire blanket to smother flames and contain the spread. This can help control the situation until emergency responders arrive.

3. Fire Suppression Strategies

Use of Water

Battery Cooling: The most effective way to stop thermal runaway is through sustained cooling, typically with large volumes of water directed at the battery. This helps reduce the temperature and interrupt the runaway reaction.

Continuous Application: EV batteries can reignite. It’s critical to continue water application until thermal imaging confirms the battery is fully cooled. This process may take several hours, and post-extinguishment monitoring is essential.

Specialised Extinguishing Agents and Tools

FX Fluids: Fire extinguishing fluids can be useful for smaller fires involving flammable battery components, though they are not a replacement for water when dealing with full battery involvement.

Fire Blankets: Effective for containment and preventing fire spread to adjacent vehicles or structures. However, they do not provide the cooling needed to halt thermal runaway.

Underbody Spray Systems: Because EV batteries are located underneath the vehicle, targeted cooling from below is the most effective way to manage battery temperatures.

PPV (Positive Pressure Ventilation): Incident commanders should consider using PPV to disperse potentially explosive gases emitted during thermal runaway.

4. Handling Re-Ignition Risks

Monitoring After Suppression

Re-Ignition Potential: Lithium-ion batteries pose a high risk of re-ignition even after the initial fire is extinguished. Continuous monitoring is essential.

Thermal Imaging: Firefighters should use thermal imaging cameras to detect hotspots and monitor temperature trends in the battery compartment.

Post-Fire Transportation and Storage

Safe Quarantine: Move the vehicle to an isolated location, away from structures and ignition sources, where it can be observed for further thermal activity.

Specialised Containers: Damaged EVs may be placed in containment units or isolation pits to control and manage any secondary incidents.

5. Coordination with Emergency Services

Emergency Responder Preparedness

Training and Equipment: Fire services must receive specialised training in EV fire response and have access to tools such as thermal imaging cameras, fire blankets, and high-volume water supplies.

Clear Communication: Provide emergency responders with detailed information about the EV’s condition, visible signs of off-gassing or fire, and any actions already taken.

Pre-Incident Planning

Engage Local Fire Services: Establish communication and response plans with local fire departments to ensure familiarity with EV-specific risks.

Organisational Protocols: Fleet operators and businesses should develop EV fire response protocols, provide employee training, and ensure on-site access to appropriate firefighting tools.

6. Post-Incident Review and Learning

Incident Analysis

Debriefing: Conduct a thorough review after any EV fire incident, involving all relevant stakeholders to assess the response and identify areas for improvement.

Protocol Updates: Use lessons learned to revise internal safety procedures, emergency response protocols, and staff training programs.

Advancing Safety Measures

Industry Collaboration: Share findings with industry partners to improve collective knowledge and best practices.

Ongoing Innovation: Stay informed about emerging technologies in battery design, fire suppression, and thermal monitoring to reduce future risks.

Conclusion

Managing an electric vehicle fire requires a specialised, informed approach due to the unique behaviour of lithium-ion batteries. Early detection, appropriate containment and suppression techniques, ongoing monitoring, and coordination with emergency services are all critical to mitigating risk. As EV adoption grows, continued training, industry collaboration, and investment in new safety technologies will be vital to keeping people and property safe.