Responding to Electric Vehicle Fires Caused by Salt Water Flooding

With EV sales expected to increase drastically in the next few years, there are growing concerns in the firefighting community about how to deal with EV fires.

One area of concern is EVs that have been flooded by salt water. According to the NHTSA, residual salt within the battery or battery components can form conductive “bridges” that can lead to short circuit and self-heating of the battery, resulting in fires. The time frame in which a damaged battery can ignite has been observed to vary widely, from days to weeks.

For example, in the storm surge in Florida that accompanied Hurricane Ian in September 2022, many vehicles were submerged at least partially in salt water. In the following weeks, at least 12 EV fires were reported in Collier and Lee Counties. One on Sanibel Island burned 2 houses to the ground. (See also: Hurricane Isaias Shows Why Storm Fire Safety Matters)

Guidance for EVs flooded with salt water

The NHTSA emphasizes first identifying any flooded electric vehicles and then moving them at least 50 feet from any structures, other vehicles or combustibles.

NHTSA's 2014 guidance for first responders PDF and second responders PDF, developed in collaboration with the U.S. Fire Administration, National Fire Protection Association (NFPA) and others, was revised after the 2012 flooding from Hurricane Sandy submerged several hundred EVs in salt water, leading to several fires in Fisker EVs. The 2014 bulletins now incorporate response guidance related to hazards from flooded EVs.

Also, the International Association of Fire Chiefs (IAFC) has a webinar (available free of charge after registration) on response to EV battery fires associated with salt water submersion.

The potential problem extends beyond flooded EVs

In all occurrences, EV battery fires can be very time- and resource-intensive for responders. There are safety risks for responders related to the emission of toxic and flammable gases from damaged batteries, and the unpredictability of thermal runaway and re-ignition. Resources for dealing with EV fires include:

• NFPA training for responders on alternative fuel vehicles.
• Fire Department Response to Electrical Vehicle Fires from the IAFC. The bulletin includes guidance for responders pre-, during and post-incident.