Fire hazards of electric vehicles
The unique fire hazards that EVs and hybrid vehicles present pose challenges particularly for first responders.
Electric vehicle fires can exceed 5,000 degrees Fahrenheit. Applying water or foam may cause a violent flare-up as the water molecules separate into explosive hydrogen and oxygen gases.
There are several common risks for first responders associated with electric vehicle fires:
- Electrical shock (up to 400 volts)
- Extremely high temperatures and thermal runaway
- Toxic fumes
- Lithium burns (respiratory and skin reactions)
- Toxic runoff
- Reignition up to 24 hours after initial extinguishment
Other dangers of EVs are thermal runaway and stranded energy, should a crash occur. A recent article in NFPA Journal details the narrative of a Tesla crash on a California highway and the immense challenges posed to first responders. In the article, the author describes the Tesla battery in particular:
“As in all Tesla models, the battery in the Model X is comprised of more than a dozen separate modules, each made up of hundreds of individual cells. All of these components are neatly packaged in a rectangular metallic case that runs the length of the chassis beneath the passenger cabin. Fully charged, the battery has a capacity of 75 kWh—roughly enough energy to power the average US home for more than two-and-a-half days, and more than enough to instantly kill anyone exposed to it. If punctured, breached, or otherwise damaged, heat can build rapidly inside the compromised battery cells and spread to surrounding cells in a cascade-like process called thermal runaway, which can lead to fire, arc flashing, off gassing, and sometimes explosions.”
This crash is an example of the unique challenges facing the vehicle industry and first responders. And a call for more research and training in handling EV incidents.