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Electric, hybrid, and hydrogen vehicle safety in crashes and fires

Emergency numbers differ by country. This page uses 911, the number for the United States and Canada. Many other countries use 112, 999, or another number. Find the number for your country.

Alternative fuel vehicles (including battery electric vehicles / EVs, plug-in hybrids / PHEVs, and hydrogen fuel cell vehicles / FCEVs) feature unique high-voltage and compressed gas technologies that require specific safety protocols during crashes, fires, or flooding.

Do this now

  1. Turn off the vehicle ignition button or key immediately after a collision to isolate high-voltage contactor switches.
  2. Step away from the vehicle and move at least 30 meters (100 feet) upwind if you smell gas, see smoke, or hear high-pressure venting.
  3. Call 911 (or your local emergency number) immediately. Inform dispatchers specifically if an electric, hybrid, or hydrogen vehicle is involved.
  4. Never touch bright orange cables inside or underneath the vehicle. Orange insulation signifies high-voltage direct current (up to 800 volts).
  5. If an EV battery catches fire, evacuate the area immediately. Battery thermal runaway fires release toxic fluorine gases and require specialized firefighter response.

High-voltage battery thermal runaway and fires

Lithium-ion batteries in EVs and hybrids store massive amounts of energy. Damaged battery cells can enter thermal runaway (a self-sustaining chemical reaction that generates extreme heat and fire):

  • Toxic gas release: EV battery fires vent hazardous gases including hydrogen fluoride, carbon monoxide, and flammable vapours. Stay upwind.
  • Fire suppression: EV battery fires cannot be put out with standard ABC fire extinguishers. Firefighters require thousands of liters of continuous water to cool the battery pack.
  • Risk of delayed re-ignition: Damaged EV battery packs can re-ignite hours or days after a crash, even after being extinguished. Towing operators must store damaged EVs in open outdoor yards away from buildings.

Submerged electric and hybrid vehicles

If an EV or hybrid is submerged in floodwater or saltwater:

  • Isolate yourself from water contact: While high-voltage systems are designed to automatically isolate during submersion, treat flooded EVs with caution.
  • Saltwater corrosion risk: Saltwater accelerates electrical short circuits and increases thermal runaway risk after the vehicle is pulled out of the water.
  • Do not start a flooded EV: Never attempt to start or charge an electric or hybrid vehicle that has been flooded.

Hydrogen fuel cell vehicle (FCEV) emergencies

Hydrogen vehicles use compressed hydrogen gas stored at extreme pressure (up to 700 bar / 10,000 PSI) to power fuel cells:

  • Invisible hydrogen flames: Burning hydrogen gas burns with a nearly invisible flame in daylight. Use a piece of paper or broom pushed ahead of you if you suspect a hydrogen fire.
  • Pressure Relief Devices (TPRD): Hydrogen tanks are equipped with temperature-activated pressure relief valves that vent hydrogen gas automatically during a fire to prevent tank rupture. Listen for loud, high-pressure gas venting sounds.
  • Emergency shutoff: Turning off the vehicle power button automatically closes the internal solenoid valves, sealing hydrogen gas inside the carbon-fiber storage tanks.