Fire hazards of electric vehicles in semi-enclosed and enclosed environments: A review

Abstract

Electric vehicle (EV) adoption has been growing continuously; however, fire hazards remain a significant challenge, especially in semi-enclosed and fully enclosed environments such as underground parking lots and tunnels. The objective of this literature review is to understand EV fire behavior in semi-enclosed and enclosed environments. Eighteen studies published between 2015 and 2025 were reviewed to examine fire behavior, thermal runaway, heat release rate (HRR), smoke dispersion, and toxic gas emissions. The review also considers health hazards, fire suppression methods, and ventilation strategies. EV fire behavior differs significantly from internal combustion engine vehicles (ICEVs), with maximum HRR reaching 6–10 MW within minutes and up to 52 MW in electric buses. Hydrogen fluoride (HF) concentrations can reach up to 488 ppm, exceeding the acute exposure guideline AEGL-2 by a factor of 40, which drastically reduces tenability time by up to 47%, especially in areas with limited ventilation. Fire suppression for EVs requires significantly more resources-around 6,000 liters of water or chemical agents compared to ICEV fires and poses a risk of re-ignition. The findings of this literature review can serve as a guideline for further studies involving experiments or simulations of electric vehicle fires in semi-enclosed and enclosed spaces. It can also be used to support legislation and establish safety standards related to EV fire incidents in parking structures, to align with government policies promoting electric vehicle adoption and accommodate future growth in EV usage.