Putting out electric car fires is more difficult because of the “thermal runaway” that occurs in batteries. Overheating in one cell can transfer heat to other cells, leading to a chain reaction, high temperatures and small explosions.
The fact that batteries are housed in durable enclosures prevents water and chemicals from reaching the burning cells. For this reason, even after the fire has been extinguished, the energy remaining in damaged cells can cause them to reignite hours or days later. Vehicles need to be monitored with thermal cameras and kept in an isolated area.
The burning of battery electrolytes can release toxic or flammable gases such as hydrogen fluoride, carbon monoxide, methane and hydrogen. Since vehicle designs and battery structures differ, it is important to determine the response method according to emergency response guides.
Why it matters
This picture shows that an incident involving an electric vehicle fire may not be over even after the visible flames have been extinguished. For response teams, this means that monitoring the vehicle afterward, moving it to a safe area and observing it with suitable equipment are as much a part of the process as extinguishing the fire. The possibility of toxic and flammable gases shows that people near the fire and those responding to it cannot act based solely on the risks of heat and flames. While different vehicle and battery designs show that the same method cannot be applied in every incident, they leave open questions about which response guide should be used and how long the risk of reignition should be monitored.