2026 FSRI Report Provides Evidence-Based Guidance for Electric Vehicle Fire Response

The Fire Safety Research Institute (FSRI), part of UL Research Institutes, has released a major 150-page report examining how electric vehicle fires develop and how effectively common firefighting strategies control them.

The multi-year research project involved 18 full-scale vehicle fire experiments using vehicles common to the North American market:

• Nine free-burn experiments involving six electric vehicles and three internal-combustion vehicles
• Nine electric-vehicle suppression experiments
• Testing of conventional hose streams, water additives, EV fire blankets and under-vehicle nozzles
• Analysis of heat release, fire growth, battery temperature, smoke, runoff, surface contamination and contaminated PPE

The report provides practical recommendations for fire departments, towing and recovery operators, salvage facilities and other agencies responsible for managing an EV throughout the incident lifecycle.

EVs Did Not Burn Hotter or Longer

One of the report’s most important findings is that EV and conventional vehicle fires were broadly similar in fire-growth rate, peak fire size, total energy release and duration.

In the unsuppressed experiments, every vehicle burned out in less than 90 minutes. Researchers found no evidence that the tested EVs consistently burned hotter or longer than comparable internal-combustion vehicles.

This is largely because the passenger compartment—including plastics, foam, upholstery and other combustible materials—represents a major part of the fuel load regardless of the vehicle’s power source.

The critical difference emerges when an EV’s high-voltage battery becomes involved. Battery involvement introduces thermal runaway, flame jetting, flammable-gas production, additional chemical contaminants and a prolonged risk of reignition.

Water Remains the Primary Firefighting Tool

FSRI recommends a conventional water-based handline attack as the first-choice strategy for an EV fire.

Researchers found that firefighters could extinguish the passenger-compartment fire in under one minute using less than approximately 760 litres—200 US gallons—of water. Rapid control of the cabin fire immediately reduced heat, smoke and chemical exposure and made it easier to determine whether the battery was involved.

The research does not support continuously applying large volumes of water to the outside of an enclosed battery pack. Vehicle construction generally prevented water from reaching and cooling the cells undergoing thermal runaway.

In the experiments, firefighters managed an involved battery by:

• Extinguishing the passenger-compartment fire
• Protecting nearby people, property and vehicles
• Preventing the cabin from reigniting
• Redirecting flames away from exposures when required
• Monitoring the battery while thermal runaway progressed to completion

Using disciplined water application, researchers resolved incidents in under 30 minutes with approximately 2,900 litres—760 US gallons—of water. All vehicle fires in the suppression experiments were managed with less than 7,500 litres.

The addition of the F-500 encapsulating agent did not produce a measurable improvement over water alone.

The report also warns firefighters not to open or pierce a battery enclosure.

Fire Blankets Introduced Additional Hazards

The experiments found that EV fire blankets could quickly control flames from the passenger compartment, but they could not stop thermal runaway inside the battery.

Battery cells continued to release flammable gases beneath the blanket. These gases could accumulate and ignite when oxygen was introduced, creating flash-fire, backdraft or deflagration hazards.

Researchers observed four deflagrations during two fire-blanket experiments. In one experiment, moving the blanket contributed to ignition of the accumulated gases. In another, operating an under-vehicle nozzle beneath the blanket produced a significant deflagration and flame release.

The report concludes that fire blankets may have limited uses, but they should not be the default method for controlling an EV fire. If deployed over an involved battery, the blanket should not be disturbed for at least one hour after the last visible smoke or flame.

FSRI advises against using a fire blanket on a burning EV indoors or in another confined environment where flammable gases could accumulate.

Chemical Exposure Remains a Serious Concern

Both EV and conventional vehicle fires produced hazardous smoke containing substances such as volatile organic compounds and polycyclic aromatic hydrocarbons.

EV fires involving the battery also produced elevated concentrations of battery-related metals and particulate fluoride. Researchers detected nickel, manganese, cobalt and lithium in post-fire contamination. Contaminants were identified in smoke, suppression runoff, surface residue and firefighting turnout gear.

The report notes that metal contamination may persist after the visible incident has ended and could become airborne again during cleanup, towing, dismantling or salvage operations.

FSRI recommends:

• Full structural PPE and SCBA for personnel operating near the vehicle
• Upwind and uphill positioning whenever possible
• Using hose-stream reach to reduce direct smoke exposure
• Avoiding contact with smoke, debris and contaminated runoff
• Continuing respiratory protection during inspection and overhaul
• Preliminary exposure reduction before disconnecting from SCBA
• Bagging contaminated gear at the scene
• Transporting contaminated gear outside the crew compartment
• Prompt showering and laundering of clothing
• Appropriate respiratory, skin and hand protection for second responders handling the vehicle and its debris

The report also cautions that battery off-gassing without visible flames may be mistaken for steam. SCBA should remain in use while emissions continue or when personnel are inspecting a damaged vehicle.

The Incident Does Not End With Extinguishment

FSRI emphasizes that movement of a damaged EV can disturb battery components, create a short circuit and initiate delayed reignition.

Before releasing the vehicle, responders should assess for:

• Smoke, vapour or continued off-gassing
• Hissing, clicking or popping sounds
• Hot spots or above-ambient battery temperatures
• Visible battery damage
• Signs of ongoing thermal runaway

Fire departments should consider escorting the tow truck to the storage facility with a suppression unit. At the tow or salvage yard, the report recommends maintaining at least five metres—16 feet—of separation between the damaged EV and other vehicles, structures or combustible materials.

This reinforces the need for coordinated procedures involving fire departments, towing companies, storage yards, salvage operators and insurers.

Five Central Operational Recommendations

FSRI’s principal recommendations to the fire service are:

1. Prioritize life safety. Identifying the vehicle’s power source must not delay occupant rescue, extrication or immediate fire control.
2. Attack the passenger-compartment fire quickly with water. This produces the fastest reduction in heat and chemical exposure.
3. Determine whether the battery is involved. Thermal runaway may be indicated by jetting flames, off-gassing, popping or hissing sounds and fire emerging from beneath the vehicle.
4. Do not waste large volumes of water on an inaccessible battery pack. If the battery cannot be controlled, protect exposures, prevent cabin reignition and monitor it while thermal runaway progresses.
5. Plan for transfer and recovery. Communicate the reignition risk, coordinate with the towing operator and use an appropriate quarantine area at the storage facility.

CESAT Perspective

This research provides strong evidence that standard firefighting equipment and familiar hose-stream tactics remain effective for controlling the main body of an EV fire. It also shows that battery involvement changes the incident’s hazards and extends responsibility beyond initial fire suppression.

An EV incident should be managed as a connected response-and-recovery operation involving firefighters, police, paramedics, towing personnel, storage facilities, salvage operators and environmental or waste services.

The findings also reinforce several important distinctions:

• The vehicle fire and battery fire are related but operationally different problems.
• Extinguishing visible flames does not necessarily mean thermal runaway has stopped.
• A fire blanket can conceal rather than eliminate battery hazards.
• Smoke, runoff, contaminated PPE and post-fire debris require exposure controls.
• Transportation and storage are part of the emergency-management process, not simply routine vehicle removal.

Members are encouraged to download and review the complete report, including the EV Fire Tactical Decision Aid and its step-by-step operational walkthrough contained in the appendices.

Report: Full-Scale Electric Vehicle Fire Experiments and Recommendations for Fire Incident Response
Authors: Adam M. Barowy, Nathaniel G. Sauer and Christian A. Vogt
Organization: Fire Safety Research Institute, UL Research Institutes
Publication date: August 4, 2026