Underground Garage EV Firefighting Strategies: A Critical Analysis
As urban landscapes evolve and parking infrastructure becomes increasingly complex, the integration of electric vehicles (EVs) into underground garages presents both technological advancement and unforeseen safety challenges. With the rapid proliferation of new energy vehicles—particularly battery-powered electric cars—the risk of high-intensity, hard-to-suppress fires in enclosed environments has surged. A recent study published in Fire Rescue 2024.01 by Fu Qiu, a technical officer at the Zhuzhou City Fire and Rescue Brigade in Hunan Province, offers a comprehensive examination of firefighting strategies tailored specifically for electric vehicle (EV) fires in subterranean parking facilities. The research underscores the urgent need for updated protocols, advanced suppression technologies, and integrated emergency response frameworks to address the unique hazards posed by lithium-ion battery combustion in confined spaces.
The transition toward sustainable transportation has placed electric vehicles at the forefront of automotive innovation. Governments worldwide are incentivizing EV adoption, with China leading global deployment through aggressive policy support and infrastructure expansion. However, as EV ownership grows, so does the frequency of battery-related fire incidents. Unlike conventional internal combustion engine vehicles, which primarily burn fuel and lubricants, EVs contain high-energy-density lithium-ion battery packs that pose distinct fire dynamics. When these batteries fail—due to thermal runaway, physical damage, or electrical faults—they can ignite with extreme intensity, release toxic fumes, and reignite even after initial suppression. These characteristics are exacerbated in underground garages, where ventilation is limited, escape routes are constrained, and structural containment can amplify heat and smoke accumulation.
Fu Qiu’s study identifies two primary causes of EV fires: battery aging and physical damage. Battery degradation over time leads to increased internal resistance, reduced energy efficiency, and diminished thermal stability. As cells age, their ability to manage charge and discharge cycles weakens, making them more susceptible to overcharging, short circuits, and localized overheating. This degradation process compromises the integrity of critical components such as separators and electrolytes, increasing the likelihood of internal short circuits. Once triggered, such failures can initiate thermal runaway—a self-sustaining chain reaction in which one overheated cell rapidly heats adjacent cells, culminating in violent combustion or explosion.
Physical damage, meanwhile, remains a persistent threat in underground parking environments. Despite advancements in battery enclosure design, impacts from collisions, uneven flooring, or debris can compromise protective casings. Even minor deformations may lead to internal short circuits, especially if insulation layers are breached. Additionally, environmental stressors such as humidity, temperature fluctuations, and water intrusion—common in poorly maintained underground structures—can accelerate corrosion and electrical leakage. Earthquakes, flooding, or equipment malfunctions may further disrupt electrical systems, potentially igniting adjacent wiring or control units. These factors collectively heighten the probability of fire initiation, particularly when vehicles are charging, a period during which electrical loads are highest and monitoring may be insufficient.
One of the most alarming aspects of EV fires, as highlighted in the study, is their high propensity for re-ignition. Traditional vehicle fires typically subside once fuel sources are depleted and flames extinguished. In contrast, lithium-ion batteries can continue to generate heat and combustible gases long after visible flames are suppressed. This phenomenon, known as “reignition,” occurs because residual energy within damaged battery cells can reignite under certain conditions, especially if cooling is inadequate or if oxygen is reintroduced prematurely. Fu Qiu emphasizes that the design of EV power systems often prevents immediate power disconnection during a fire, allowing ongoing energy discharge that sustains combustion. Moreover, the extensive use of lightweight composite materials in modern EVs—while beneficial for efficiency—tends to be highly flammable and difficult to extinguish once ignited.
The risk profile of EV fires in underground settings is further elevated by the inherent limitations of such environments. Enclosed spaces restrict airflow, impeding natural smoke dispersion and creating hazardous conditions for occupants and responders alike. High concentrations of carbon monoxide, hydrogen fluoride, and other toxic byproducts generated during lithium-ion battery combustion can incapacitate individuals within minutes. Visibility drops rapidly, evacuation becomes disoriented, and rescue operations face significant delays. Furthermore, the structural integrity of underground garages may not be designed to withstand prolonged exposure to extreme temperatures, raising concerns about collapse risks during extended firefighting efforts.
Given these complexities, Fu Qiu advocates for a multi-layered approach to fire management that begins well before an incident occurs. Central to this strategy is comprehensive risk assessment. Fire prevention must start with a detailed analysis of garage layout, ventilation efficiency, fire suppression systems, and vehicle distribution patterns. Factors such as proximity of charging stations, availability of emergency exits, and placement of fire barriers should inform operational planning. The study stresses the importance of evaluating not only structural elements but also human factors—such as pedestrian traffic density and public awareness of emergency procedures. By identifying vulnerabilities in advance, facility managers and fire departments can implement targeted mitigation measures, including enhanced monitoring systems, improved signage, and regular drills.
A critical component of pre-incident preparedness is the integration of intelligent detection technologies. Modern underground garages should be equipped with multi-sensor fire alarm systems capable of detecting early signs of thermal anomalies, gas emissions, and electrical faults. Infrared cameras, smoke detectors with chemical analyzers, and battery management system (BMS) telemetry can provide real-time data on vehicle health and environmental conditions. When coupled with automated alert mechanisms, these systems enable rapid notification of both on-site personnel and emergency services, significantly reducing response times. The study recommends that all EV charging zones be monitored continuously, with alarms linked directly to local fire command centers.
Once a fire is detected, immediate on-site intervention is essential. The first phase of response centers on scene control and life safety. According to Fu Qiu, the initial actions must prioritize human evacuation. Alarm systems should activate instantly, broadcasting clear instructions in multiple languages if necessary. Personnel must guide occupants along designated escape routes, ensuring that panic does not lead to stampedes or blockages. Simultaneously, efforts must be made to clear access paths for emergency vehicles. Obstructed driveways or collapsed barriers can delay fire apparatus arrival, costing precious minutes in fire suppression and rescue operations.
Equally important is the isolation of the affected zone. Ventilation systems should be shut down promptly to prevent smoke from spreading to unaffected areas. Fire-rated doors and dampers must close automatically to compartmentalize the blaze. For electric vehicles, it is imperative to cut off power supply to charging stations and disable onboard systems remotely if possible. This reduces the risk of electrical arcing and limits the energy feeding the fire. Establishing secure perimeters around the incident site protects bystanders and allows firefighters to operate without interference.
When fire suppression begins, traditional methods require adaptation. Standard firefighting tactics involving direct water application may not be effective—and in some cases, counterproductive—when dealing with lithium-ion battery fires. Water can conduct electricity, posing electrocution risks, and may react violently with certain battery chemistilities, generating flammable gases. Instead, Fu Qiu recommends a combination of cooling, containment, and inerting techniques. High-volume water spray, applied from a safe distance, can help cool the exterior of the vehicle and adjacent structures, preventing thermal propagation to nearby cars. However, direct jet streams should be avoided, particularly toward battery packs, to minimize the chance of electrolyte leakage or explosive reactions.
An innovative method proposed in the study involves the use of undercarriage cooling kits and high-expansion foam barriers. By deploying specialized blankets or enclosures beneath the burning EV, responders can suppress vapor release and insulate the battery from oxygen. High-multiplicity foam blankets the vehicle’s lower section, creating a sealed environment that limits combustion while facilitating gradual cooling. This technique has shown promise in pilot tests, significantly reducing smoke emission and delaying reignition. In scenarios where no lives are at immediate risk, the application of liquid nitrogen is also considered viable. Injected into the fire zone, cryogenic nitrogen rapidly lowers ambient temperature and displaces oxygen, effectively smothering flames in an oxygen-deprived environment. While logistically challenging due to storage and delivery requirements, this method offers a non-conductive, residue-free alternative to conventional agents.
Ventilation and smoke extraction play a pivotal role in underground firefighting. Due to the confined nature of subterranean spaces, toxic gases accumulate quickly, endangering both evacuees and responders. Mechanical smoke exhaust systems must be activated early to channel fumes upward and out of the structure. Positive pressure ventilation fans can assist in clearing escape routes, while negative pressure units remove contaminated air from the core fire area. Coordination between fire crews and building engineers is crucial to ensure that HVAC systems do not inadvertently recirculate smoke. Portable ventilation equipment should be staged at entry points for rapid deployment.
For large-scale incidents, interoperability among emergency agencies becomes essential. Underground garage fires involving multiple EVs demand coordinated responses from fire, medical, hazardous materials, and police units. Fu Qiu stresses the establishment of an on-site command post equipped with real-time communication networks, thermal imaging feeds, and situational awareness dashboards. This centralized hub enables strategic decision-making, resource allocation, and inter-agency coordination. Mutual aid agreements with neighboring jurisdictions can bolster manpower and equipment reserves, particularly when extended operations are anticipated.
Post-fire investigation and accountability form another cornerstone of Fu Qiu’s framework. After suppression, a systematic forensic process must be initiated to determine the root cause of the incident. This includes securing the scene, collecting physical evidence such as charred battery modules, wiring fragments, and charging equipment, and preserving digital logs from vehicle BMS and garage surveillance systems. Eyewitness accounts, maintenance records, and environmental data should be compiled for analysis. Independent experts in battery technology, electrical engineering, and fire dynamics should be engaged to conduct technical evaluations, ensuring objectivity and scientific rigor.
Liability assessment follows this investigative phase. Depending on findings, responsibility may lie with vehicle manufacturers (for defective components), property managers (for inadequate maintenance or safety protocols), or individual owners (for improper charging practices). Legal frameworks must be applied to determine negligence, compliance with safety standards, and potential regulatory violations. A formal report should document the sequence of events, causal factors, responsible parties, and recommended corrective actions. Transparency in this process fosters public trust and drives systemic improvements in safety practices.
Ultimately, Fu Qiu’s research calls for a paradigm shift in how society approaches EV fire safety in enclosed environments. It is no longer sufficient to rely on legacy firefighting doctrines developed for gasoline-powered vehicles. The unique behavior of lithium-ion batteries demands specialized training, updated equipment, and revised operational guidelines. Fire departments must invest in EV-specific education programs, incorporating hands-on drills with decommissioned vehicles and simulated fire scenarios. Collaboration with automakers, battery producers, and urban planners is essential to align safety standards across industries.
Moreover, urban development policies should mandate fire-resistant construction materials, dedicated EV parking zones with enhanced suppression systems, and mandatory emergency drills for garage operators. Public awareness campaigns can educate EV owners about safe charging habits, warning signs of battery failure, and proper emergency responses. Technological innovations such as smart battery diagnostics, automatic fire suppression modules integrated into EVs, and AI-driven anomaly detection systems hold promise for future prevention.
In conclusion, the increasing prevalence of electric vehicles in underground parking facilities necessitates a reevaluation of fire safety protocols. Fu Qiu’s analysis provides a robust foundation for developing science-based, operationally sound strategies to combat EV fires in confined spaces. By combining proactive risk assessment, advanced suppression techniques, interagency coordination, and thorough post-incident review, cities can better protect lives, property, and public confidence in the transition to clean mobility. As the automotive industry accelerates toward electrification, fire safety must keep pace—not as an afterthought, but as a core element of sustainable urban design.
Fu Qiu, Zhuzhou City Fire and Rescue Brigade, Fire Rescue 2024.01