ELECTRIC VEHICLE CHARGING
As Electric Vehicle (EV) sales continue to increase due to global climate and environment concerns, consequently the number of workplace EV charging points has also increased significantly due to: -
Employers looking to assist employees with the ability to charge vehicles whilst at work.
The number of electric fleet vehicles is increasing (cars, light commercial vehicles, HGVs, buses/coaches etc.).
Employers are trying to reduce their carbon footprint.
This risk guidance document focuses on property and liability hazards associated with the charging process of electric cars, light commercial vehicles, HGVs and buses/coaches only and provides general guidance on appropriate control measures to implement.
The following is out with the scope of this guidance document: -
The charging of forklift trucks.
Fire and life safety hazards, and appropriate controls, associated with lithium-ion batteries.
Introduction
Currently, all electric vehicles are powered by batteries with some form of lithium-ion chemistry, and if they catch fire, the consequences will be serious – potential thermal runaway of the battery cells, which is a highly exothermic reaction creating toxic, flammable and/or explosive chemical components. The charging process presents an opportunity for thermal runaway due to excessive currents or if the battery cells are damaged.
However, this is not the only hazard associated with EV charging (it is an electrical risk after all), and there are a number of factors that need to be considered prior to, and following, the installation of EV charging stations at your premises to minimise the potential of a loss event.
Design stage
When deciding on installing EV charging stations, the premises and physical location need to be considered.
It’s also important to focus on fire and electrical safety plus associated potential hazards, standards and legislative requirements. Fires involving lithium-ion batteries present new challenges to fire fighters as they can re-ignite after initially being extinguished. So thought needs to be given to the possibility of fire spread to the surrounding premises/area.
Relevant national legislative requirements need to be considered, such as: -
Electrical Regulations
Building Regulations
Fire Regulations
Disability Regulations
A fire risk assessment needs to be carried out that considers the control measures required when selecting and designing charging/parking areas.
Location
External
Where practical, all EV charging stations/parking bays should be located externally, and at least 10 metres from buildings, important infrastructure (i.e. transformers, plant, sprinkler tanks and fire pump room etc.) and external storage of combustible materials (i.e. waste storage areas, flammable liquid or gas storage, idle timber pallet storage area etc.). Vegetation should be no closer than 2 metres.
Where it is impossible or impracticable to meet the above spatial separation requirements, consider the following: -
A minimum of 1 hour fire resistance is recommended for exposing wall construction. Identify the fire rating of the exposing wall(s), and if necessary, increase the existing fire rating, install an external wall drencher system or protect it with an appropriate fire rated barrier.
Install appropriate fire rated barriers around the EV charging bays if within 10 metres of external storage of combustible materials or important infrastructure.
Internal
Internal EV charging stations are not recommended as it is extremely difficult for the fire brigade to ensure final extinguishment involving an EV within an enclosed space, plus the generation of toxic gases hinders fire-fighting activities.
However, where charging stations are to be located internally, the following should be followed: -
The charging/parking bays should be located as close as possible to the external exits, and preferably at ground level, to allow easy access for the fire brigade, and to assist with the removal of the vehicle(s).
The charging/parking area should be located within a fire compartment providing a minimum 60 minutes fire resistance. Where the construction of the building has been assessed as combustible, then the fire rating of the compartment should be increased to 120 minutes.
Basement level/underground charging/parking areas present additional complexities for firefighting therefore these compartments should achieve a minimum of 120 minutes fire resistance.
The generation of toxic gases is particularly problematic for firefighting activities in below ground/internal charging areas. In addition, hydrogen and oxygen gases are produced that can exacerbate a fire or create an explosive atmosphere, thus it is essential that adequate and appropriate ventilation (mechanical or natural) is provided.
Internal Electric Vehicle charging and parking areas should be equipped with automatic fire detection. The fire detectors should be installed close to the charging units/Electric Vehicles. Alarms should be automatically transferred to an approved and permanently attended alarm receiving centre.
Installation of sprinkler protection is recommended. The sprinkler system should be designed and installed in accordance with recognised global/national codes (LPC, CEN, VdS, FM etc.) by engineers having appropriate certification. If sprinkler protection is already installed, the level of protection should be reviewed with any remedial actions necessary being implemented before charging commences.
Automatic fire detection and sprinkler systems should be interfaced with the power supply for all vehicle chargers to isolate the power automatically in the event of activation.
Whether located externally or internally, charging stations/bays should not be installed in any location where flood or excessive surface water run-off and pooling is considered a risk.
Electrical Hazards
Overloading existing electrical installations can result in frequent interruptions, damage, injury and fire. A survey of the electrical capacity and demand of the site/premises must be completed to determine the number and type of charge points that can be installed. Once the load details are known, then the type and number of chargers can be calculated.
Electrical circuits intended to supply any EV charger must be fit for purpose and suitable for the electrical load. They should be designated for the use of chargers only, and not part of a ring main or used for other purposes.
Charging units should be installed in accordance with manufacturers guidance and national regulations and by a competent and regulated electrician.
Charging stations should be protected against impact with kerbs or impact barriers. At the same time, kerbs and impact barriers may help to maintain a clear distance of 1 m minimum between the charging station and the Electric Vehicle.
Where rapid charging points (known as Direct Current (DC) Fast Charge and Mode 4) are provided, they should be clearly signposted to differentiate them from conventional charging points, highlighting the hazards associated with Direct Current.
A residual current device (RCD) must be provided to automatically separate the charging station from the electrical power supply in case of a ground fault. It is recommended these are tested on a 6 monthly basis.
Emergency manual isolation of charging stations should be provided in a prominently sign posted and easily accessible location to allow safe shutdown of equipment in the event of a fault or failure of equipment. When choosing a location consider whether this will remain accessible if a vehicle is on fire.
In case of an electrical malfunction, the charging station should be automatically disconnected from the electrical supply.
Ensure the proposed cable is of sufficient length to reduce the stress. It is to be of sufficient length to reach any vehicle’s charging inlet no matter how it is parked i.e. reversed, nose in etc.
Appropriate signage with suitable and sufficient information and instructions on usage which mitigates risk of injury and property damage, emergency procedures (including emergency contact details) and general user safety etiquette e.g. prohibition of smoking (Terms of Use Agreement) should be provided.
All installation, maintenance and servicing activities should be carried out by suitably certified contractors.
Charging units should be maintained and serviced in accordance with manufacturer’s recommendations, unless the suggested service programme is superseded by local/national requirements. The exception to this being ‘Rapid’ or ‘Fast’ charge units which should be maintained and inspected on an annual basis. Planned maintenance and servicing should be accompanied by arrangements for reactive maintenance e.g. user reported unit damage.
It is important local site staff are provided with suitable training highlighting the increased hazards of DC equipment (if applicable), how to operate the equipment, requirements for day to day visual inspections, how to isolate the charging units and emergency procedures for shut down.
It is recommended charging units are visually inspected on a daily basis. If the charging unit, cables and connectors and/or associated infrastructure is mechanically damaged or electrically deficient, the charging unit should immediately be shut-off and be locked until appropriately repaired or replaced. Suitable warning signs should be provided.
Vehicle charging should be avoided when the site is unattended, for example overnight or at weekends.
Charging Bay Design & Operation
Provide adequate spacing and access for the fire brigade, in case of a fire. It is critical that the fire brigade have easy access to the vehicle as they need to gain direct access to the batteries.
When the charging cable is plugged into the EV, users should refrain from overtly stretching the cable and/or trailing the cable across pedestrian walkways or access points to minimise the risk of slips, trips and falls. The distance between the vehicle charging unit and the vehicle should be kept to a minimal and trailing cables covered using a safety protection mat/cover where necessary (the cable should be of sufficiently bright and different colour to the footpath so as to make it clear and obvious to users of the footpath).
It is important that the design of the electric vehicle charging units and associated parking areas comply with national/local disability laws. Is there sufficient space around the vehicle, access to the charging unity and height of the cables?
Environment – Appropriate safety measures for all user profiles should be considered. Considerations should be made on lighting, noise, ventilation, charging bay space, height of the charging unit and general housekeeping e.g. removal of combustible materials.
Other Considerations
Provide suitable and appropriate containment for contaminated extinguishment water run-off to protect the local environment.
Provide a safe “quarantine” area for any EV(s) that are suspected to have a damaged or faulty battery, and for EVs that have been involved in a fire. This should be at least 15 metres from any building or important infrastructure.
Provide a fire risk analysis and a pre-fire plan in close collaboration with the local fire department, to prepare for effective firefighting and a removal of fire-damaged EVs during or after a fire event.
