6-19 Hybrid/electric and electrical vehicle safety
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.
Although manufacturers build many 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
- familiarize firefighters with the hazards of hybrid or electric vehicles
- 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
These are some important safety considerations for hybrid or electric vehicles.
Hybrid and electric cars can experience multiple classes of fires:
- Class A — Ordinary combustibles (for example, wood, fabrics and some plastics)
- Class B — Flammable liquids (for example, fuel, oil and grease)
- Class C — Live electrical equipment (for example, wiring and batteries)
- Class D — Combustible metal (for example, magnesium)
Battery fires may initially show from under the vehicle.
Quiet operation of vehicle
The hybrid or electric vehicle may still be powered on even though there may be no engine noise. This poses a risk of the vehicle accidentally moving. Electric vehicles (EVs) move silently, never assume it is powered off and it won’t move.
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 (such as, 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 and 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
Consider the following when responding to a hybrid or electric vehicle incident:
- heightened situational awareness must be maintained while working on roads for extended periods of time
- park fire apparatus uphill and upwind
- high voltage systems need to be shut down before entering damaged hybrid or electric vehicles, or before starting extrication procedures
- wear full PPE 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
Removing a patient from the vehicle
Procedures for removing someone from a vehicle may vary depending on the vehicle type and design. Consider the following to work safely when removing someone from an electric vehicle after an incident.
Consider the following when preparing to remove someone from a vehicle after an incident:
- 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
Stabilizing and cutting the vehicle
Consider the following when stabilizing and cutting into an electrical vehicle:
- vehicle construction and weight distribution could change standard strategies for stabilization
- for rescue struts, 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
Consider the following to ensure safe 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
Lifting the vehicle
Consider the following when lifting an electric vehicle:
- 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 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
Read NFPA 921 Guide for Fire and Explosion Investigations for safety during post-response investigation, arson investigation and vehicle investigation.
As part of the Electric Vehicle Safety Training project, the National Fire Protection Association (NFPA) is working with vehicle manufacturers to help inform fire services and other first responders about hazards associated with electric vehicles. This information may be found in NFPA - Emergency Response Guides for Alternative Fuel Vehicles for specific vehicle types.