Last month, a House subcommittee hearing was held on examining the risk of the dangers of electric vehicles (EV) fires for first responders. Representative Jay Obernolte, R-California, said, “Electric Vehicle (EV) fires are fundamentally different from traditional internal combustion engine fires, and they present new dangers that our first responders need to be prepared for.”
The significant risk is when a Lithium-Ion battery experiences “thermal runaway.” A thermal runaway is a chain reaction within a battery cell that occurs between the anode and cathode when its separator is compromised. Once it begins, it can be very difficult to stop because the energy stored within the battery is released suddenly and can rapidly reach the temperature where a chemical reaction occurs (752 degrees°F/400 °C). This drives the temperature higher, causing further chemical reaction, cell venting of toxic gases, smoke, and fire.
Gaseous suppression and water systems are not effective to fight the EV fire. The current method of extinguishing these types of fires requires enormous amounts of water applied for hours up to days. Firefighters in Massachusetts, had to dump 22,000 gallons of water on a burning EV for two hours to put it out.
These fires are also at risk for reignition, hours or even days after later, and therefore require long term supervision. Firefighters in California had to create a makeshift pond to submerge a smoldering EV because it kept reigniting.
Besides the difficulties of extinguishing the fires, there are other unique risks. Dan Munsey, Fire Chief for San Bernardino County Fire Department in California, explained that EV fires give off “copious amounts of toxic chemical gases,” and current personal protective equipment (PPE) has not been designed to protect firefighters from these types of gases. Among those chemicals, Munsey said, is hydrogen fluorine which would equate to breathing acid, damaging lung tissue, and causing swelling and fluid accumulation in the lungs.
Added to the risks is the cost. PPE that firefighters wear costs $5,000-$10,000 per ensemble. One way firefighters can control the fire and prevent the gases from spreading is to cover them with blankets that cost $3,000-$5,000 each. In response to an EV fire in a home garage, in Denver, the fire department used one of these blankets to contain the smoke and gases, and then towed the vehicle to a tow yard, where they dug a pit, filled it with water, and immersed the vehicle in the pool. Even before the fire starts, the cost for training firefighters about EV fires is estimated at $2,500 for each firefighter.
Today, we have ~3.1 million EVs in operation and while EV fires are not common, experts in the auto industry estimate that there will be nearly 130 million EVs on America’s roads by 2030.
