By Mark D. Layfield, PE, LEED AP
As electric vehicles (EVs) usage continues to grow, so have concerns about fire safety, particularly due to the unique challenges posed by lithium-ion battery fires. While EVs are statistically much less likely to catch fire than internal combustion engines (such as gasoline or diesel-powered vehicles), the nature of battery fires introduces new risks that require updated safety protocols for both individuals and emergency responders.
Understanding the Risks
EV fires are often more intense and longer-lasting than traditional vehicle fires. This is primarily due to the phenomenon of thermal runaway, where a damaged or overheated lithium-ion battery cell triggers a chain reaction, releasing flammable gases and extreme heat. These fires can reignite hours or even days after being extinguished, posing ongoing hazards. In enclosed spaces like parking garages or residential garages, the accumulation of flammable gases from a battery fire can lead to explosions, especially if ventilation is inadequate. Additionally, fires involving EVs that have been compromised via collisions, flooding, etc. are particularly dangerous, as internal battery or wiring damage may not be immediately visible.
Insurance companies are increasingly focused on the fire risks associated with electric vehicles (EVs), particularly when it comes to protecting structures like homes, parking garages, and commercial buildings. This is because EV fires burn hotter than traditional vehicle fires, and are more difficult to extinguish, due to extreme temperatures, self-sustaining thermal reactions, and the possibility of reigniting. The result of these factors is a greater risk for property damage and human injury, including smoke inhalation.
Current Safety Recommendations
Although the National Fire Protection Association (NFPA) does not currently have a code or standard relating to EV fire safety, nor do insurance companies have standard guidelines, such documents are being developed. Until those documents are released, here are some current recommendations:
- The International Association of Fire Fighters (IAFF) strongly advises against using fire blankets on EV fires involving batteries. While blankets can smother flames by cutting off oxygen, they do not stop thermal runaway or the release of flammable gases. This can lead to gas buildup and potential explosions beneath the blanket.
- Water remains the most effective tool for cooling and suppressing EV fires. Although water alone may not fully extinguish an EV fire, it will help contain it. Insurers often require or strongly recommend the installation of advanced fire suppression systems in areas where EVs are charged or stored and up to 15’ beyond. Sprinkler systems should be checked and tested regularly to confirm that they are in correct working order, and systems should be rated for higher hazards than standard systems, including high-heat fires.
- Consider using thermal detection systems that can identify overheating batteries early.
- Provide dedicated fire zones with fire-resistant materials around EV charging areas. This may also include fire-resistant barriers between EV charging station areas or providing adequate physical separation between charging stations.
- Consider locating EV charging stations and possibly even EV parking spaces outdoors and/or away from structures.
- Use only certified, professionally installed EV charging stations.
- Provide adequate ventilation for indoor EV charging and parking areas to prevent gas buildup.
- Where installed in parking structures, locate EV charging and parking areas near entrance and exit points, where firefighters can more easily access them. Do not locate below grade or above grade where firefighter access would be difficult. Coordinate with your local fire authorities.
- Consider using thermal imaging cameras or sensors to monitor battery temperatures.
- Train staff and residents on emergency response protocols. Conduct regular risk assessments with certified fire safety professionals. Document all safety measures and maintenance records for EV infrastructure.
- Keep fire extinguishers and emergency shut-off switches near charging stations.
- Work with insurers to ensure all safety controls are recognized in underwriting. Due to the perceived risks, insurers may limit or exclude coverage for properties with EV charging stations unless safety measures are in place. Properties with inadequate fire protection may face increased premiums.
These recommendations reflect a growing consensus that while EVs are generally safe, their unique fire risks require proactive planning and investment in safety infrastructure. Collaborating with insurers and fire safety experts is essential to protect both people and property. Remember that codes and standards are always evolving, so stay on the lookout for the latest updates.
Image Credit: TVA EnergyRight
The choice of EV charging level depends on various factors, including daily driving habits, the type of EV owned, and the availability of charging infrastructure. For short daily commutes, Level 1 charging may be sufficient. For regular daily use and quicker charging times, Level 2 charging is more appropriate. For long trips and rapid refueling, Level 3 charging is the best option.
Mark is a Licensed Professional Engineer, a LEED Accredited Professional, and Partner at Reese Hackman.