Background

Hybrid or electric vehicles are powered by a combination of internal combustion and electric motors. The electric motors are powered by high voltage battery packs.

Concerns and hazards

Although manufacturers build a number of safety features and devices into their vehicles to prevent accidental shock to the driver, the hybrid or electric vehicle’s high voltage system can pose a shock hazard to firefighters in an emergency situation.

Actions for employers

Employers must:

  • familiarize firefighters with the hazards of hybrid or electric vehicles

Employers should:

  • train firefighters on the means provided by manufacturers to shut down high voltage vehicles
  • develop a policy or standard response guideline for electric/hybrid vehicle incidents

Safety considerations

These are some important safety considerations for hybrid or electric vehicles.

Fires

Hybrid and electric vehicles can experience multiple classes of fires:

  • Class A — ordinary combustibles (such as wood, fabrics, some plastics)
  • Class B — flammable liquids (such as fuel, oil, grease)
  • Class C — live electrical equipment (such as wiring, batteries)
  • Class D — combustible metal (such as magnesium)

Battery fires may initially show from under the vehicle.

Quiet operation of vehicle

The hybrid or electric vehicle may still be powered on when there is no engine noise, posing a risk of accidental movement. These vehicles move silently. Never assume the vehicle is powered off or that it will not move.

Pre-incident planning

Consider the following, during pre-incident planning:

  • there could be a combined fire, extrication and hazmat incident
  • develop guidelines for when crews should have limited interaction and allow the vehicle to burn (defensive tactics)
  • increased time may be required to manage and control electric vehicle fires
  • during call taking, have dispatch assess whether an electric vehicle is involved and whether it is near a structure (home, garage, parking garage)
  • markings to indicate hybrid or electric vehicles vary
  • the location of high voltage cables varies — there may be high voltage cables in the cut zones

Incident actions

Consider the following when responding to a hybrid or electric vehicle incident:

  • heightened situation awareness must be maintained while working on roads for extended periods of time
  • park fire apparatus uphill and upwind
  • wear full personal protective equipment with SCBA with face-piece
  • use a thermal imaging camera to assess electric vehicle hazards, such as:
    • the extent of the fire
    • if it is a compartment fire
    • if the fire includes the electric components of the vehicle
  • secure the electric vehicle, where possible, by:
    • putting the vehicle in park
    • turning the vehicle off
    • chocking the wheels

The best method for managing or controlling a battery fire is with large quantities of water. Secure a large, continuous and sustainable water supply from one or more hydrants.

Secondary ignition risk

The heat from the fire may have damaged additional cells, which may require additional suppression activities. Batteries should always be treated as energized.

Following initial suppression activities, monitor for:

  • heat from the battery
  • possible secondary ignition

Have sufficient fire personnel and apparatus on scene for an extended operation.

Safety during overhaul

Consider the following to work safely during overhaul:

  • do not make contact with any high voltage components
  • a high voltage cable may run under the vehicle chassis, posing a shock hazard when cutting into, lifting or stabilizing hybrid or electric vehicles — the high voltage cable should not be cut, disconnected or handled due to the shock hazard
  • high voltage systems need to be shut down before entering damaged hybrid or electric vehicles
  • there may be residual power in other batteries or other energy sources

Patient extrication

Extrication procedures may vary depending on the vehicle type and design. Consider the following to work safely during patient extrication from an electric vehicle.

Preparations may include:

  • charge a hose line and staff it with a firefighter in full PPE ready to fight fire, as there is a significant risk of a delayed fire
  • shut down high voltage systems before starting extrication procedures

Considerations for vehicle stabilization and cutting include:

  • vehicle construction and weight distribution could change standard strategies for stabilization
  • for rescue structs, do not use any holes that may have been caused by the crash and do not pierce, puncture or create any purchase point in the battery case — this could cause an electrocution and/or fire hazard
  • the battery compartment forms part of the structure — consider this when determining how to extricate
  • remove trim to verify what is being cut before the cut is made
  • do not cut any high-voltage cabling

Considerations for air quality:

  • harmful/flammable gasses may be released from batteries and may cause eye, nose or throat irritation — wear full SCBA
  • using a vent fan may be appropriate to blow fresh air into the passenger compartment of the vehicle

Consider the follow for lifting electric vehicles:

  • electric vehicles should be lifted at the rocker panel
  • be certain to complete any lifts over a large surface area

After an incident

Thermal events with the battery system could continue for some time after the initial incident. To keep workers safe, consider the following:

  • batteries should always be treated as energized and pose an ongoing risk
  • have the fire apparatus escort the vehicle to the recovery location, if possible
  • inform fire investigators of the hazards of the electric vehicle

Applicable regulations and acts

To learn more about the applicable regulations and acts you can read:

  • Occupational Health and Safety Act
    • clause 25(2)(a) for providing information and instruction to a worker
    • clause 25(2)(d) for making workers aware of hazards
    • clause 25(2)(h) for taking every precaution reasonable in the circumstances to protect workers

Related

Firefighter’s Cancer Prevention Checklist — use this self-audit tool to learn how to protect fire personnel from exposure to contaminants that may cause cancer or other occupational illnesses.

NFPA 921 Guide for Fire and Explosion Investigations — learn about safety during post-response investigation and arson investigation.

Emergency Response Guides for Alternative Fuel Vehicles — fire services and other first responders can find information about electric vehicle hazards.

Tesla First Responder Information — first responders can find information about how to safely handle Tesla products in case of emergencies or fires.