Interview William S. Lerner     

Amid active discussions by our authorities to implement preventive measures for EV accidents in relation to the Incheon (Cheongna) electric vehicle fire, I had a conversation with William S. Lerner, a U.S. EV infrastructure specialist and risk mitigation consultant, about safety measures for battery-related vehicles, vehicle information and identification, on-site fire response, and considerations for charging and infrastructure. As the cause and results of the late September incident emerged, we spoke again, and here is the report.

written by Sang Min Han _ han@autoelectronics.co.kr


William S. Lerner
He is an Electric Vehicle Infrastructure Specialist and Risk Mitigation Consultant, focusing on safety issues in the transportation sector, including fuel cell vehicles, hydrogen refueling stations, battery electric vehicles, electric vehicle charging, and fuel supply and infrastructure. Additionally, he is an independent inventor and a Fellow of the Royal Society of Arts(F.R.S.A.) in Manufactures and Commerce. He holds numerous U.S. patents and has additional filings in his portfolio aimed at expanding his work in the transportation and safety fields.

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EV Garage Fire in Korea, and Future Mitigation Strategies (autoelectronics.co.kr)






Hi William, welcome back. When we spoke last, it was just after the Korean EV High-Rise fire. Electric Vehicles, Safety and Risk Mitigation are your areas of expertise. Can you share what you’ve learned since the fire? Has it changed your perspective?
William       Thanks, it is great to have the opportunity to chat again. My perspective has not changed, I’ve been focusing on EV and infrastructure safety for more than a decade. 

We are seeing more and more significant fires related to electric vehicles and lithium-ion batteries and it is apparent that these are not isolated events. Fires are being reported around the world, in increasing numbers. As part of my work, I examine these events daily. Although they occur regularly, these events unfold in many ways. We used to think of a battery pack as multiple cells enclosed in a secure case that sat beneath the car but that may no longer be true. 








So, car batteries are configured differently today?  
William       Yes. Now, batteries are not always a collection of cells within a solid case. Some batteries may be designed so that the individual cells drop out of the bottom in an emergency. 
One vehicle manufacturer has encased the individual cells using a pack or module with open architecture. You can see the individual cells. The cells and modules in these cars can explode and shoot up and out of the vehicle. In a recent EV fire, three individual cells shot through the roof a vehicle reaching a height of fifty feet. This is not an isolated case- the UK fire service has documented cells shooting sixty-six feet during a e-bike fire. 

There are some cars with the battery placed within the cabin, under the rear seat for example. Each battery configuration presents unique challenges.
Because battery packs can be ejected and individual fuel cells can shoot and roll great distances, we cannot think of a burning EV as a single discrete unit. We must be prepared to suppress a fire that is at a distance from the vehicle itself. Each fire has the potential to become several fires. 
As a Safety and Risk Mitigation Consultant, my role is to identify risks and work with clients to implement strategies designed to decrease the number of events that jeopardize the infrastructure and cause personal injury, while protecting first responders and the public.



Let’s start with infrastructure. Can you talk about the cause and effect of the fire at Incheon?
William       We may never know what caused the specific injury or insult to this battery, but we do know that in most cases like this, one or more of the cells that comprise the lithium-ion battery can be damaged and following a chemical reaction it starts to burn, igniting the other cells or modules. There may be other defects in the battery pack, specific to some battery designs, that can provoke a similar reaction. 

A battery can be damaged in many ways. In the USA, there are six million car accidents annually. Every accident is a potentially damaged battery. This statistic does not consider the number of vehicles that hit the curb, run over a pothole or experience an unreported minor “fender bender”. Anytime an electric vehicle hits the curb or a speed bump, there is potential to damage the battery pack. 
These fires burn at incredibly high temperatures, causing devastating damage to the surrounding infrastructure. A gasoline powered vehicle burns at roughly 1500F, an EV fire typically burns at 4000- 5000F. This is hot enough to melt steel! 
A building’s normal defenses are destroyed in the face of this incredible heat. Sprinklers can fail and cease to function and steel infrastructure can be compromised. If you’ve ever seen a photograph of an electric vehicle after a fire, there is nearly nothing left- often just a pile of ashes.

In a parking structure, cars are close together and the fire easily jumps from one vehicle to the next, creating a path of destruction it its wake. Remember, an EV fire does not have to start with the EV. If a traditional gasoline car is parked near an EV, and the gasoline powered car catches fire, it can easily spread to the EV, setting off a new cascade of events. As we know, forty vehicles were incinerated and more than eight hundred were damaged at Incheon, resulting in more than six hundred insurance claims to date.
In the Luton airport fire, photos reveal that the fire burned in irregular patterns, leaving a pattern of damage that resembles Swiss cheese. Parts of floors are missing and this appears to be related to the location of EVs that were parked there.
To be clear, the concern is not limited to parking structures. Lithium-ion battery fires can happen anywhere. There have been several serious fires in shops selling e-bikes. Many of these are small shops with apartments above the store. In New York City, we have seen several fires that started when someone brought an e-bike into an apartment.

There are parking structures underground, on the street level and above offices, shopping malls and apartments. Each location presents specific challenges. Parking structures are incorporated into apartment buildings, shopping malls, airports, office towers and schools. There are even apartment buildings, in many cities around the world, where you can drive your car right into an elevator and park in your apartment.







It sounds like the most important thing is to extinguish a lithium-ion battery fire as quickly as possible.   
William       Unfortunately, it is not as simple as that. Fires caused by lithium-ion batteries are very difficult to extinguish. We never really talk about extinguishing these fires, we use the term “suppression”.  Many first responders believe that suppression requires incredible amounts of water. A recent fire involving an electric truck in California required 50,000 gallons of water to control the fire. This is enough water to fill a 20 x 50 foot swimming pool!

People have used fire suppression blankets, encapsulating agents, foam, misting, vehicle immersion tanks and chemical extinguishers to control these fires with varying degrees of success. There is no solution that is guaranteed to work. We are still searching for the answer. As a result, many firefighters use methods that are unproven or dubious. 

Once the fire is suppressed, it may only be temporary. Lithium-ion batteries spontaneously re-ignite for several weeks after the initial event. We cannot think of a battery as a single unit- each may be comprised of many thousands of cells. A fire can become a rolling wave of reignition involving the cells that were not part of the original event. New research suggests that water may aggravate the burning cells. Clearly, we do not understand the best methods of suppression.

These fires happen very quickly. In the video from the Incheon fire, you can see white smoke coming from the car, and in seconds, it is engulfed in flames. So, we are dealing with a rapid progression to a full blaze, with little or no warning and a fire that is difficult, if not impossible to control.



So, is it the rapid sequence of events and the high temperatures that cause so much damage to buildings and other infrastructure?
William       The short answer is yes. However, it is not so simple. As these fires burn, they off-gas toxic emissions commonly referred to as HF. The gases may also contain metallic particles, toxins, and other carcinogens. Breathing these fumes can damage lungs, bones, skin and eyes. The role of toxic gases in a particular event is determined by the space the vehicle occupies, ceiling height and the design of the ventilation system as well as the components of the battery emissions. As first responders douse the burning vehicle with water, the runoff can contain toxic substances if the individual cells split. This water will run into the streets, drainage systems and ultimately can work its way into the water supply if aquifers are affected. 
The intense heat associated with these fires (4000F-5000F) can destroy a building’s drainage system. When these systems fail, the toxic runoff can travel in unknown and unplanned directions, depositing forever chemicals around the site.
When a fire occurs in a parking structure located on the roof, the toxic runoff can run down into the offices, stores or apartments below. This toxic runoff can infiltrate the porous components of the infrastructure and may render the building impossible to repair.
After a fire, walls and ventilation fans are covered in soot. In cases such as these, the soot may also be contaminated with toxic and forever chemicals.







With the extensive damage that you are describing, it makes me wonder if a building that survives an EV fire can be remediated?
William       There is no easy answer but a building that is severely damaged may need to be demolished and rebuilt. Whether or not this happens will depend upon the degree of damage, the owner’s insurance, and the condition of the site. A building site that is contaminated with a host of “forever chemicals” may need many years and many millions of dollars worth of remediation. 

The costs are staggering. Razing and rebuilding, environmental remediation and monitoring, and the aftermath of personal injuries result in costs that easily reach into hundreds of millions of dollars annually.

After demolition, rebuilding and site remediation, the building is still vulnerable to the same type of EV fire in the future. In August 2024, in Queens, NY there was a fire at an e- bike shop which destroyed the building. The same shop burned because of an e-bike fire roughly one year ago. The retail space and apartments in the building were all destroyed. This is why it is so important to develop policies, procedures and guidelines as we move ahead.







This all sounds very frightening. Is there anything that we can do to make this better?
William       I don’t think we need to be frightened- we need to be prepared. When I work with clients, I try to be the calming voice in the room. In many ways, this reminds me of the beginning of the COVID pandemic. We knew there was a problem, and we tried everything possible to contain it. With time, we understood the reality of the situation and were able to address the root cause. It is similar with the EV situation today. We need a measured approach to understand the problems and address them.

Essentially, a battery is a device used to store energy. As we move forward, new methods of storage and new battery types will be developed, and they will almost certainly bring new problems and challenges. This is a story that is developing in real time and will require constant attention and monitoring.

Electric vehicles and lithium-ion batteries are part of our culture. It is my job to help develop policies, procedures and real-life strategies for enjoying their benefits while keeping the public, first responders, end-users and our infrastructure safe. There are several components to my work. 

Part One is understanding how to plan for new construction and adapt the existing infrastructure to maintain a safe environment. For example, new construction often plans for the deployment of vehicle charging stations because it is popular and seen as an “added value”. But deployed improperly, they will increase risk to the building and to the public. While surveying properties, I have seen clients place a number chargers side by side, increasing the risk of an EV fire spreading from one car to another. I have also seen a garage located under a large apartment complex with multiple charging stations. The ventilation system for this underground garage not only goes up to the building, it also vents to an outdoor courtyard that is heavily used by the tenants and their children.

Part Two is the providing the education necessary for First Responders to ensure that they manage these fires and remain safe. We must be sure that all first responders know the best approach to managing these events. Every first responder must understand the basic science behind these fires, and the potential for toxic fumes and runoff if they are to stay safe while they work to keep us safe.

Part Three is working with manufacturers and developers to create the best protective gear and equipment possible. Higher temperatures, toxic fumes, wetter environments all need to be considered when handling a lithium-ion event. Currently, first responders “turn-out” gear does not match the event. Their protective gear cannot withstand the temperatures and severe conditions produced by a EV fire. Remember that EV fires can be 3500F hotter than a gasoline fire. The face shields in use today can withstand temperatures up to approximately 400F and bunker gear is designed for temperatures up to roughly 1550F.








This is certainly a more complex issue than many people realize. We all have a lot to learn. Where do we go from here? 
William       That’s an excellent question and I wish there was a simple answer. There is no single approach to address all the potential problems. 

There has been a lot of focus, in Korea and other countries, on the battery’s “state of charge”. While it is true that many EV fires occur while a car is charging, many fires do not start this way. EV fires can occur when a car is charging, being driven or when parked. 
Similarly, people advocate for battery inspections. But an inspection will only tell us what is happening at a moment in time. Certainly, finding a damaged battery on an annual inspection will prevent a potential disaster, but a healthy battery can be damaged driving away from the inspection center.

There has been talk about the requirement for sprinklers wherever EV’s are parked. A steady and powerful supply of water may be important, but will the sprinkler system survive the extreme temperatures that occur with an EV fire? A persistent reporting error in many news articles that I’ve seen is the temperature of these fires. As I mentioned earlier, EV/ Lithium-Ion battery fires burn between 4000F and 5000F, not the 1000F that we often see mentioned.

Additionally, if the sprinklers are overhead, the effect on a burning battery pack located on the underside of a vehicle is limited.
One must consider the design of ventilation systems for indoor or underground parking structures. EV fires release a cocktail of toxic fumes. Although we commonly talk about Hydrogen Fluoride, the vapor contains other chemicals such as cyanide, formaldehyde and cobalt particles. We do not fully understand the forever chemicals and their effects. As this gas vents upward, outward and sideways, will it be carried into the building above or vented to the outside? When families returned to the apartment building in Incheon, after the recent EV fire, many residents suffered rashes, ocular and respiratory problems. 

Toxic runoff is a very real problem when managing the aftermath of an EV fire. Hydrogen fluoride and other chemicals can be absorbed in the ground and find their way to the water table and aquifers. In many cases, the cost of remediation of these toxic events is significantly more than the cost of physical damage to a building- even in a case where an entire building must be demolished and rebuilt.
How would we remediate a building that survives an EV fire? Toxic vapor and soot has coated the walls and lines the ventilation ducts. Black mold appears on the walls, as water and toxins are absorbed by the porous building materials. Restarting the ventilation systems may simply push the toxins further into the building. 

Speaking of toxic fumes, how are we preparing our first responders to handle these problems? They need education and adequate personal protection systems designed to ensure that they can suppress the fire, rescue victims, and preserve infrastructure without being injured or poisoned. Police are often the first to arrive and the last to leave the scene. Videos show that they are on site, without protection. We are putting our first responders in harm’s way when we do not provide adequate protection.

When homes, apartments, shopping malls, hospitals, airports, railway stations, parking structures and offices are rebuilt following a devastating event, it is important that they are designed with all of this in mind. Unless every project is approached thoughtfully and carefully, we may rebuild, only to face the same problems down the road.

All of this comes with a huge price tag. As these events become more common, what will happen to insurance premiums? How will a self-insured business realistically maintain a reserve large enough to manage these costs?

I could go on and on but I don’t want to leave you with the impression that this is a hopelessly dangerous situation. Building owners, construction companies, architects and engineers need to work with an expert in the field to troubleshoot and vet their designs and plans. There are certainly some common-sense basic rules that we should all follow but each building site will present unique challenges and even more unique solutions to these problems. 



Thank you again William. You’ve certainly given our readers a lot to think about. Please keep us updated as conditions in the field and best practices change to adapt.