Why 6 flooded EVs burst into flames after Hurricane Ian

By Andres Picon | 10/21/2022 06:21 AM EDT

Lithium-ion batteries can burn for hours after igniting with the help of conductive salt water. The fires threaten to cloud the image of EVs as the Biden administration is trying to replace millions of gas-powered cars with electric ones.

A Tesla Model S that suffered a battery fire amid flooding sits in a pool of water after firefighters in Naples, Fla., extinguished the flames.

A Tesla Model S that suffered a battery fire amid flooding sits in a pool of water after firefighters in Naples, Fla., extinguished the flames. North Collier Fire Control & Rescue District in Naples, FL

In the days after Hurricane Ian made landfall in Florida, firefighters near Naples put out six blazes in electric vehicles that had been submerged in seawater.

It was a first. The North Collier Fire Control & Rescue District had never before dealt with an EV fire. The hurricane’s storm surge flooded thousands of vehicles with salt water, and the surprising fires added a challenge to a fire department that was already overwhelmed by search and rescue operations in the wake of the deadly storm.

The fires also put a political target on electric vehicles.

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The flooded cars’ lithium-ion batteries were loaded with energy when highly conductive salt water poured over them. They burned for “hours and hours” and required “thousands upon thousands” of gallons of water to extinguish — a far more intensive process than what a typical gas car fire would require, said Heather Mazurkiewicz, a fire department spokesperson. At least one EV reignited after flames were put out, destroying two houses that had survived the storm, officials said.

The blazes quickly drew the attention of state officials. Jimmy Patronis, Florida’s state fire marshal and chief financial officer, took to social media last week and sent letters to the National Highway Traffic Safety Administration (NHTSA) and EV manufacturers with pointed questions about vehicle fires. In a letter to Elon Musk, CEO of Tesla Inc., Patronis lamented the potential of EVs to “spontaneously combust” and described the recent fires as “surreal, and frankly scary.”

Sen. Rick Scott (R-Fla.), a member of the Commerce, Science and Transportation Committee, sent letters of his own to EV manufacturers and Transportation Secretary Pete Buttigieg, that accused automakers of putting consumers under the “potentially life-threatening misimpression” that EVs work after saltwater submersion.

“This emerging threat has forced local fire departments to divert resources away from hurricane recovery to control and contain these dangerous fires,” Scott wrote to Buttigieg. “As increasing numbers of EVs come to market nationwide, this threat demands action by the U.S. Department of Transportation to develop guidance to properly caution consumers about this risk posed by EVs submerged in saltwater.”

The fires threaten to cloud the image of EVs at a time when manufacturers, environmentalists and the Biden administration are striving to replace millions of gas-powered cars with zero-emitting ones to meet the nation’s ambitious climate goals. Sales records of EVs are being broken with every passing quarter, but some industry groups are worried that negative attention from the fires could compound existing skepticism around electric cars, such as range anxiety, relatively high sticker prices and grid capacity issues.

Electric vehicle makers and supporters are pushing back on the narrative that EVs are less safe or more likely to combust than other types of cars. The accusations from Scott and Patronis appear to have been politically motivated or misleading, some supporters said.

“We are absolutely concerned about any safety issues regarding electric vehicles, it’s just that they must be put in context,” said Marc Geller, spokesperson for the Electric Vehicle Association.

He and other EV advocates pointed to a report from AutoInsuranceEZ published this year. Researchers with the car insurance quote provider examined data from the National Transportation Safety Board (NTSB) and the Bureau of Transportation Statistics and found that there are roughly 25 fires for every 100,000 EVs sold, and 1,530 gas car fires for every 100,000 internal combustion vehicles that are sold.

“One Tesla fire gets more news than 10,000 gasoline car fires, whether it’s because people are super interested in Tesla or because people are still fighting the battle to suggest that electric cars are not ready for prime time or not good,” Geller said, adding that they “are kind of confessing their own ignorance about electric cars.”

Joe Britton, executive director of the Zero Emission Transportation Association, a trade group whose members include EV manufacturers, said Scott’s assertion that EVs are less safe than gas cars after a flood is misleading.

Lead-acid batteries, found in both electric and gas vehicles, can catch fire after saltwater submersion just like EVs’ lithium-ion batteries, though the energy density and risk of reignition is much smaller, said Vilas Pol, a Purdue University professor of chemical engineering.

Gasoline and other flammable fluids in an internal combustion car pose their own fire risks and can pollute the environment after a crash or flood, Geller said.

EPA has a webpage dedicated to debunking “electric vehicle myths,” including the notion that EVs are less safe than gas cars. All vehicles, electric or otherwise, must meet the same federal safety standards, and EV battery packs are required to meet separate testing standards, according to the webpage.

“For Sen. Scott, it’s timely, it’s topical, it’s a good way to kind of slip a new narrative in and take some potshots,” said Britton, the trade group official. “But ultimately, at the end of the day, many people will realize that this is a strikingly low percentage of [electric] vehicles” catching fire.

“There’s obviously entrenched fossil fuel interests that want to keep us tied to a carbon intensive transportation system and feel threatened by the deployment and a transition to clean, zero-emission vehicles,” Britton said.

Scott will be up for reelection in 2024. Patronis, a Republican, is running for reelection as state CFO in November. He did not respond to requests for comment.

Clare Lattanze, Scott’s press secretary, said in a statement that the senator’s “priority is the safety of Floridians and our first responders,” and that his “call for action to develop safety protocols and properly caution consumers about the risk posed by EVs submerged in floodwaters is a commonsense step that should be welcomed by all — especially EV manufacturers.”

Managing EV fire risk

Lithium-ion batteries have a “significant amount of energy density,” and the lithium inside “has a tendency to burn until it completely burns off,” said Pol. When salt water causes a short circuit by linking the battery’s positive and negative terminals, the resulting fire can last hours and even reignite after it’s extinguished.

The NTSB issued a set of safety recommendations last year following an agency investigation into four EV lithium-ion battery fires after high-speed crashes. The recommendations include improved standards, additional research into fires and improving emergency response guidance from EV manufacturers.

In June, eight manufacturers including Honda Motor Co., Hyundai Motor Co. and Volkswagen AG improved their emergency response guidelines in response to the NTSB recommendations. Other manufacturers, including Tesla, Ford Motor Co., General Motors Co., Toyota Motor Corp. and Stellantis NV, were “making progress on the steps identified in the recommendation,” according to the agency.

Jeannine Ginivan, senior director for public policy communications at GM, said the automaker received the letter from Scott and “will respond as appropriate.” GM’s electric vehicles are designed and tested to withstand extreme temperatures and water intrusion, she said. Several other automakers did not respond to requests for comment.

“EVs and gas engine vehicles have many commonalities but also some differences that require evolving practices in the first responder community,” Ginivan said in a statement. “GM is committed to working with these heroes across the country through grassroots, hands-on training exercises.”

The North Collier Fire Control & Rescue District in Florida responded to a Facebook comment from a user accusing the fire department of unfairly bashing EVs by pointing out the fire risks following Hurricane Ian.

“We aren’t saying anything about the safety of the vehicles under normal operating conditions,” the department wrote. “We just aren’t operating under normal conditions and vehicles are reacting differently. While there may be more gas-powered fires than EV/hybrid, the resources to extinguish … either type are vastly different.”

A Department of Transportation spokesperson said the department will follow up with Scott directly and that DOT and NHTSA have been working with Florida officials to provide safety guidance related to flooded electric and gas vehicles.

In a letter to Patronis, NHTSA said it has released two reports on the immersion of EVs and batteries in salt water, and provided funding to the National Fire Protection Association to develop and promote first responder EV training.

EV fires ‘starting to be a concern’

The spotlight on recent EV fires raised questions about their use in areas that will likely see more hurricanes and flooding as a result of climate change.

At least two of the vehicles that burned after Hurricane Ian were Teslas, which have been recalled more than any other type of EV for a range of issues. Other EV manufacturers, including GM and Hyundai, have issued recalls in recent years due to problems with their lithium-ion batteries.

“That’s starting to be a concern, and that’s something I think the industry should address,” Vanessa Ton, senior manager of research and market intelligence at Cox Automotive, said in an interview last month.

Pol, the Purdue engineering professor, said he would be hesitant to purchase an electric vehicle. “I am aware of how much energy [an EV’s lithium-ion battery] can store,” he said, “and that could go wrong one way or another.”

Still, Americans purchased more than 200,000 electric vehicles in the third quarter of this year — a new record, according to Cox Automotive. Tesla dominated those sales, amounting to about two-thirds of market share.

Automakers are taking advantage of innovations that can reduce EV fire risk, including improvements in sensors that can detect issues with the battery, Pol said.

Despite the fires, EV advocates remain confident in the technology and optimistic about the transition to electric transportation.

“The trajectory is clear,” said Geller of the Electric Vehicle Association. “None of this will interrupt the year-over-year increase in sales of electric cars in a period where already, year over year, there are fewer gasoline cars.”

“I think we’ve got to deal with it,” he said of the rare battery issues, “but this is not a big deal.”