An article from "Motortrend". July 17, 2023 by Scott Evans
https://www.motortrend.com/features/you-are-wrong-about-ev-fires/
"Gas- and diesel-powered vehicles catch fire way more often than EVs, but you wouldn’t know that from the headlines.
There's a car fire roughly every five minutes in America. The vast majority of them never make the news. But if a Tesla or a Chevy Bolt catches fire? It's probably on the front page nationwide and going viral online. If the sensational headlines and social media videos are to be believed, EVs are flaming deathtraps that could spontaneously combust at any minute.
EVs are new and different, and their fires pose some different challenges for first responders, so some coverage makes sense; we ourselves cover unusual or noteworthy instances. But if electric vehicles are no more likely to catch fire than any other car on the road, the headline frequency can be misleading. In fact, the data says they account for a tiny fraction of all car fires.
According to National Fire Incident Reporting System data collected by the U.S. Fire Administration and analyzed by the National Fire Protection Association (NFPA) , an average of 117,370 passenger vehicles caught fire every year between 2013 and 2017 (the most recent data available). That works out to 321 car fires per day, or a car fire every five minutes. How many of those car fires are EVs?
The fact is, no one knows for sure. No American government agency we're aware of breaks out car fires by drivetrain, nor do they granularly break out car fires by vehicle age. There is no database that tells you how many EVs catch fire each year or what percentage of EVs catch fire. Similarly, no database tells you how many cars running on gas or diesel catch on fire. The NFPA analysis even goes out of its way to mention the lack of data on EVs and makes no claims about the frequency or likelihood of EV fires.
The Swedish authorities, however, are keeping track. The Myndigheten för Samhällsskydd och Beredskap (MSB, or Authority for Social Protection and Preparedness) recently released the first report of its kind specifically tracking EV fires in Sweden and comparing them to combustion-powered vehicle fires and the results are clear: EVs are much less likely to catch fire.
Per the MSB, just 29 EVs and 52 hybrids caught fire in Sweden between 2018 and 2022. On average, 16 vehicles powered by batteries (EVs and hybrids combined) catch fire there each year. On average, 3,400 passenger vehicles catch fire each year in Sweden, meaning EVs account for 0.4 percent of all passenger vehicle fires there annually. Hybrids account for 1.5 percent, for a combined total of 1.9 percent of all passenger vehicle fires.
Put another way, gas- and diesel-powered cars account for 98.1 percent of all passenger vehicle fires in Sweden each year on average.
Combustion-Powered Vehicles Are 29 Times More Likely To Catch Fire
According to MSB data, there are nearly 611,000 EVs and hybrids in Sweden as of 2022. With an average of 16 EV and hybrid fires per year, there's a 1 in 38,000 chance of fire. There are a total of roughly 4.4 million gas- and diesel-powered passenger vehicles in Sweden, with an average of 3,384 fires per year, for a 1 in 1,300 chance of fire. That means gas- and diesel-powered passenger vehicles are 29 times more likely to catch fire than EVs and hybrids.
The Problem Isn’t Getting Worse
With more and more EVs, hybrids, and plug-in hybrids (PHEVs) being sold every year, it's reasonable to wonder whether that rate of fires in those cars will increase. The MSB study found that after a rise in fires from 2019 to 2020, the rate is basically unchanged over the past 3 years with 20 EV and hybrid fires in 2020, 24 fires in 2021, and 23 fires in 2022. In that same time period, the MSB reports the number of EVs in Sweden has more than doubled to nearly 611,000. Prior to 2020, fewer EVs and hybrids caught fire with 8 in 2018 and 6 in 2019.
Not All EVs Are Made The Same
Note these numbers include all hybrids, plug-in hybrids, and EVs and not just ones using lithium-ion batteries. Up until 2021, the vast majority of hybrids used nickel-metal hydride batteries, which don't burn the same way lithium-ion batteries do.
The MSB also notes that not all of the fires included in its numbers involved the battery pack. In some cases, other parts of the vehicle burned but the fire was put out before it reached the batteries.
We should also point out there are some EVs and hybrids sold in Sweden that are not sold in the U.S. and some that are sold here that aren't sold in Sweden, so the fire risk may differ slightly in our two countries.
Electrical Problems Aren’t the Leading Cause of Car Fires
Not having an engine and its accompanying mechanical systems might actually reduce the risk of a vehicle fire. According to the NFPA, the leading cause of vehicle fires is mechanical failure or malfunction, accounting for 45 percent of all such fires. Electrical problems are a distant second, accounting for 23 percent of the total. Not having gasoline, hot exhaust, and controlled explosions on board significantly reduces the possible ways for a fire to start.
Age Matters More
In fact, the analysis shows older cars are far and away the most likely to catch fire and the risk of fire increases the older a car gets. A total of 77 percent of all car fires that occurred in 2017 involved vehicles made in 2007 or earlier, so those at least 10 years old or older. The original Tesla Roadster didn't come out until 2008, and only 2,500 of those were built. The first mass-market EV, the Nissan Leaf, wasn't released until 2010. Only the earliest modern EVs, of which very few were sold, are 10 years old today. The NFPA report cites worn-out parts and deferred maintenance as the likely cause of increased fire danger for older cars.
EV Fires Are Harder To Put Out
It's true that car fires involving vehicles with lithium-ion batteries must be handled differently than other car fires both because of the risk of high-voltage electrical shock and the way lithium-ion batteries burn. When extremely overheated, lithium-ion batteries experience what's called thermal runaway, a chemical process that isn't as easily extinguished as a gasoline fire in part because it doesn't require oxygen. They also carry a higher likelihood of reigniting after the fire is believed to be extinguished.
Because of this, it can take far more water to put out a fire with a lithium-ion battery than a typical car fire. Automakers who have supplied guidelines to the NFPA generally suggest 3,000 gallons of water or more to put out an EV fire.
In the meantime, many fire departments are issuing much simpler guidance: If an EV battery is on fire and there's minimal risk of the fire spreading to other vehicles, structures, or the environment, just let it burn itself out. The International Association of Fire Chiefs recommends "consideration and tactics [that] may be categorized in offensive or defensive mode. This may be based on exposures and the extent of fire which may include actions to let the vehicle burn." The city of Phoenix, Arizona, suggests in its official handbook "once life safety has been addressed, fire companies should determine if they should suppress the fire or simply allow the vehicle to burn … once the batteries have gone into thermal runaway, we understand that the vehicle is most likely a total loss. Control efforts must consider life safety, property conservation, exposure protection, environmental protection, and firefighter safety."
Numerous organizations, including various levels of government and nonprofits, are working to train fire departments on best practices for extinguishing EV fires, and research is being done into better techniques and improved fire-suppressing chemicals. Most departments are already familiar with procedures for avoiding electrical shocks, as hybrids have been on the road for more than 20 years now. Manufacturers continue to denote high-voltage componentry and wiring with orange coloring and prominent labeling.
The firefighting procedures also extend to how burned EVs are handled once the fire is out. Because thermal runaway is a chemical chain reaction, damaged lithium-ion batteries remain at risk of reigniting for far longer than gasoline or diesel. Once an EV fire is put out, the remains will need to be transported to a holding yard prepared to handle a reignition. These yards typically follow additional procedures, such as keeping burned EVs farther away from other flammable objects and monitoring the remains for reignition.
Do the Math
The simple fact is we've had gas- and diesel-powered vehicles for more than 120 years, and they've been catching fire since day one. We're used to it. We've accepted it as a fact of life and we've done our best to make them safer while devising better ways to put them out. EVs seem new and different, but EVs have existed for nearly as long—they just haven't been this popular in a century. EV sales are now growing so fast they'll be just as unremarkable as every other car on the road sooner rather than later. So, too, will be EV fires."
All kidding aside the carnage, cost, and resources used to put out an EV fire usually tops a similar size gas or diesel powered vehicle fire, and I bet it causes a lot more pollution too. As far as getting accurate statistics, good luck with that too.
