Electric vehicle charging in parking garages presents new hazards

You have probably been asked to provide electric vehicle (EV) charging stations on your campus. The rising popularity of EVs is creating demand for employers to provide charging stations, and while it is true that we don’t typically fill the tanks of our fossil fuel-burning colleagues while they are at work, the pressure to provide EV charging stations remains. If you are considering installing charging stations in your parking garage, you should understand the risks associated with that decision.

Fires in parking garages aren’t a new problem, but the introduction of EVs does pose a new risk. Currently, only around 1% of cars on the road are electric, and we do not have enough data to fully understand the potential risks that EVs can create in our daily environment. Studies show that the risk of fire is about the same between EVs and internal combustion engine (ICE) vehicles, but there is research comparing total EV and ICE fires in various locations, e.g., on the road, parked, charging or in an accident. Another study reports that over a third of all EV fires happen while connected to energized alternating current or direct current charging stations, or within 1 hour of being disconnected, indicating that there may be a greater risk of a fire during EV charging. 

So, what, we have a fire and we put it out; that is what our suppression systems exist for, right? Well, that is another subject under investigation at the moment. The modern car contains a lot of plastic, and, in fact, it’s not uncommon to find high-density polyethylene gas tanks in modern ICE vehicles. The Fire Protection Research Foundation (FPRF) has begun looking into this issue and has a report on modern vehicle hazards in parking garages. The additional risk of an EV charging fire to a parking garage full of plastic burning vehicles, melting fuel tanks and increased fire loads is a new challenge that needs further research. 

To add to the complexity, an EV fire is extremely difficult to put out. The recommendation to firefighters to deal with EV fires is to apply very large amounts of water (literally thousands of gallons!) directly to the outside of the battery pack, potentially for up to 24 hours. This typically requires lifting the vehicle onto one side to flood water onto the battery pack. While that may be feasible for an EV fire on the street, it is difficult to do within a parking garage. 

In addition, an EV battery fire burns intensely over a long period and is likely to spread the fire to nearby cars. The EV fire also burns extremely hot at the ground level, potentially eroding through a concrete floor, now making vehicles on lower ramps susceptible to the spreading fire as well.  

If possible, hold off on installing charging stations within parking garages. Instead, place them in the parking lot, perhaps under a basic cover structure. Reach out to your responding fire department, and talk to them about the possibility of an EV fire in your parking garage and how they would handle it. Additional information for fighting EV fires can be found in the FPRF report Emergency Response to Incident Involving Electric Vehicle Battery Hazards.