Guidance

Recovery operators: working with electric vehicles

Updated 4 December 2023

Introduction

There has been a rapid increase in the number of vehicles with an electric powertrain on public roads, which use high voltage (HV) systems incorporating high energy batteries and this trend will continue. For the motor vehicle industry, HV systems are defined as those operating at voltages of 60 volts DC and up to 1500 volts DC.

These systems pose different hazards from those associated with an internal combustion engine and these hazards need to be considered when working with such vehicles. 

The information in this guidance provides a reference for professionals involved in the roadside recovery of all types of electric vehicles (EVs), to better understand the hazards associated with these vehicles and the expectations on themselves and others. This guidance is not exhaustive, is not intended to be a training document and should not be used as an alternative for undertaking suitable training.  

Electric vehicles

There are many different types of vehicles incorporating electrified powertrains, including:

• battery electric vehicles (BEV)
• hybrid electric vehicles (HEV)
• plug-in hybrid electric vehicles (PHEV)
• mild hybrid electric vehicles (MHEV)
• range extended electric vehicles (REEV)
• fuel cell electric vehicles (FCEV)

The term ‘EV’ may be used to describe any of these vehicle types.

All EVs use a battery for energy storage. The battery, along with an electric motor, can be used to propel the vehicle either by itself or in conjunction with an internal combustion engine. Several different battery types can be found within different EVs, and while they may be manufactured differently, they do share some common hazards.

Vehicles with large energy requirements, such as BEVs, PHEVs and REEVs usually incorporate a lithium-ion (Li-ion) battery. Newer HEVs are also increasingly using Li-ion batteries. There are 6 main types of Li-ion battery used in automotive applications, which use slightly different materials, but the hazards presented are the same. The batteries in these vehicles pose a higher risk to recovery operations than for other EVs, due to their physical size and mass, and the amount of energy they contain.

HEVs tend to use smaller batteries, with a lower capacity. Often these batteries are of nickel metal hydride (NiMH) chemistry, which is more stable than Li-ion and therefore poses a reduced risk.

MHEVs frequently use a 48V system which is not designated as HV. Like the higher voltage systems, there is an electric shock risk associated with the 48V system but, with a much lower risk of electrocution. While many MHEVs use NiMH batteries, a good number also use a Li-ion batteries.

It should be noted that as there is no easy way for a vehicle recovery operator to check the battery type, the same precautions should be taken when recovering any EV.

In addition to batteries, FCEVs use hydrogen stored at high pressure and a fuel cell stack to generate electricity. Additional safety training and the use of high-sensitivity gas detectors to determine the occurrence of gas leakage will be required for these types of vehicles. The number of FCEVs that are registered remain low but could become more common in larger vehicles such as heavy goods vehicles (HGVs) and buses.

This guidance:

• helps recognise if an EV is in a condition that could pose a hazard
• provides a high-level view of the topics that need to be taken into consideration when recovering EVs

It does not replace the need for suitable training and should be read in conjunction with:

• NHSS 17/17B
• PAS 43 - Safe working of vehicle breakdown, recovery and removal operations
• the Institute of Vehicle Recovery (IVR) EV/Hybrid Protocol
• the SURVIVE Group best practice guidelines for safe vehicle recovery operations

This guidance does not consider the hazards posed by conventional powertrains (petrol or diesel) which may also be present in the case of an HEV. Nor does this guidance consider the hazards posed by the high-pressure hydrogen systems found in FCEVs.

Training

Both first and second responders should receive suitable safety training on the dangers posed by EVs, in addition to that for normal vehicle recovery operations. Training is offered by many independent organisations, and each may cover different aspects of dealing with EVs and in different levels of detail. The information in this guidance may serve as guidance to understand which aspects of EV recovery should be covered by training for recovery operators only.

For recovery operators working with EVs it is recommended that training covers an understanding of EVs, their operation and awareness of the dangers they may pose when working with and around them. Training should also cover how to mitigate against hazards that may exist around a damaged EV. These hazards include chemical, electric shock, explosion and fire hazards.

In all circumstances, it is important that recovery professionals recognise the limits of their knowledge and experience. Recovery operators should not attempt to work on a vehicle that is in an unsafe condition and if the hazards posed go beyond any training received on their role.

Safety equipment

Most EV recoveries can be undertaken in the usual manner using conventional procedures and protective equipment.

In some cases, use of specialist personal protective equipment (PPE) and respiratory protective equipment (RPE) may be necessary to protect against the specific chemical, fire and electric shock hazards that may exist for EVs. Whilst an outline of relevant PPE and RPE is provided in this guidance, its use should be covered in relevant training. Vehicle recovery operators may or may not need to employ some, or all, of the PPE and RPE mentioned in Table 1 depending on the specific recovery scenario encountered.  All PPE should be certified to appropriate standards to ensure suitability. Table 1 in this guidance gives recommendations for this.

PPE, such as electrical safety gauntlets, over-gloves and HV safety hooks are available for interaction with the HV systems, although their use may be more suited to workshop settings rather than roadside recovery scenarios. Electrical safety gauntlets can be easily damaged on sharp edges that could be present on damaged vehicles and they must always be visually inspected before use. It is therefore also recommended that a set of electricians’ over-gloves are available to protect the electrical safety gauntlets when in use. Over-gloves can only be used in conjunction with the electrical safety gauntlets. Used by themselves they will not protect against an electric shock or electrocution hazard. 

For chemical hazards, suitable gloves and RPE should be worn. RPE must shield for both particulates and gases or vapour, and filters should protect against toxic gases such as hydrogen fluoride (HF). Eye protection can also be worn for electrical and/or chemical protection. After a vehicle has been on fire, there is a risk of hydrofluoric acid contamination. Calcium gluconate gel should be carried in the first aid kit to neutralise any acidic contact with the skin. Again, PPE and RPE for chemical hazards may not be required for roadside recovery operators. All PPE and RPE mentioned should only be used if the operators have received specific training in their use and if their use aligns with the expectations of the recovery scenario.

When dealing with badly damaged vehicles, especially around the HV systems, an infrared non-contact digital thermometer could be considered for use to help monitor the temperature of a battery pack casing and assess its stability.

It is important for recovery operators to be alert and:

• listen for hissing, screaming and popping sound
• perceive any strange toxic odour around the EV
• look out for any (cathode) material ejection in form of metal nanoparticles and thin toxic fumes/rocket-like flames

Table 1: Recommended standards for personal protective equipment.

Personal Protective Equipment (PPE)	Recommended Standards
Electrical safety gauntlets	BS EN 60903 Class 0 (1000V)
Over-gloves	BS EN 388 and BS EN 420
Safety gloves (chemical protection)	BS EN 374 for chemical protection
Respiratory protective equipment	BS EN 14387 and BS EN 405
Eye protection	BS EN 166

How to be SAFE

When undertaking recovery work on any vehicle, remember the acronym SAFE.

Study

Study the area to recognise if an EV is involved in the incident. Consider its location and condition to determine if that will impact the recovery operation.

Assess

Assess the risks for the recovery operation and identify any potential dangers, including those for any bystanders or surroundings. Consider if these dangers can be removed or if they could cause an additional hazard as the recovery operation begins.

Formulate

After completing a risk assessment, formulate a plan, or method statement. This will consider how to mitigate the identified risks and reduce the likelihood of causing additional dangers. Consideration should be made of how the plan will change if things do start to go wrong.

Execute

Execute and monitor the plan to complete the recovery operation. Use a dynamic risk assessment to monitor the environment and if circumstances change, reassess the situation and modify the plan. Further help may be needed from the emergency services.

S: study

Before starting any recovery operation, take time to study the situation and collect as much information as possible, especially from first responders at the scene. Taking time to collect this information will allow identification of any potential hazards. You should assess whether you have the necessary competency and training to deal with the situation in hand, or whether you will need assistance to complete the operation.

Vehicle recognition

On arrival at an incident, it is very important that any vehicle(s) equipped with an HV system is (are) identified. This will influence the actions needed to ensure safety. Most EVs outwardly look like their petrol and diesel counterparts.

One way of identifying an EV is to use the DVLA vehicle enquiry website. Entering the vehicle registration will identify if the vehicle is a hybrid or electric model under the ‘Fuel Type’ field.

There may be vehicle labels such as ‘Hybrid’, ‘PHEV’, ‘EV’ or other markings. Blue or blue-tinged logos or body trim may also help to identify these types of vehicles. Some manufacturers, such as Tesla, only produce vehicles with electric powertrains.

The following features could also indicate the vehicle has a HV system:

• registration plate with a green band (from December 2020 onwards)
• orange cables – all HV cables and connectors on EVs should be orange in colour
• non-compliance can occur and so you should not use this feature as a sole indicator of a HV system
• large HV components, such as the battery pack, motor or invertor
• warning stickers on components, usually yellow with the ISO electrocution symbol
• electrical charging socket, this could be under the vehicle symbol on the front grille, or under a ‘fuel cap’ cover on the side or rear of the vehicle
• vehicle has a charging cable stored in it
• lack of an exhaust pipe, although hybrids will still have an exhaust pipe
• electric vehicles do not use a manual gearbox, so the gear lever is likely to look more like the selector of an automatic model

If you can see through the window of the vehicle from the outside, the vehicle dashboard and instruments may show information relating to the HV system:

• ‘Ready’ light or EV indicator
• EV power mode switches
• rev counter replaced with a power flow indicator
• battery state of charge (SOC) information
• HV diagnostic lights

It is important to note that vehicles without any of these features may still have a HV system.

Location and condition

The location of the incident and condition of the vehicle need to be considered. Undertake an initial visual inspection of the vehicle. If the vehicle is damaged and/or where an electric shock risk is identified, then avoid contact with the area of the vehicle. Ensure that the vehicle is made safe and suitable PPE is worn to protect against risk of electric shock.

Many EVs have an emergency response guide (ERG) that can be downloaded from the manufacturer’s website. This may help to identify locations on the vehicle that contain HV systems and will also include additional emergency safety information. There are also online systems that can help, such as the Euro RESCUE app for mobile phones, which is a comprehensive database of ERGs for offline viewing, or professional mobile data terminal (MDT) systems that are often used by the emergency services.

Moving an EV

It is not recommended to tow EVs on their wheels because this can cause electrical power to be generated, that could damage the HV systems.

See the section of this guidance on towing or moving an EV for more information.

Connection to a charger

If the vehicle is connected to a charger, ensure that the charger power is isolated, and the charger cable disconnected. If the charger station has been damaged, vandalised, or there is any damage to the charging lead itself, inform the operator of the charging station. You should not touch a damaged charging lead.

Submersion in water

If an EV is submerged in water, then refer to the ERG for guidance and follow current industry guidelines on vehicle recovery from water, including appropriate PPE for water rescue. If the submerged vehicle is still attached to a charger, then the charger should be made safe, and the charge lead removed before any recovery operation. In general, the HV systems are isolated from the chassis and are designed for protection against water ingress.

Being in the water next to the vehicle should not pose any additional risk of electric shock, although caution should be taken as all hazards may not be apparent through a visual inspection. Following submersion, and once the vehicle has dried out, there is a risk of an HV electrical battery fire. First responders should be prepared to respond to a potential fire risk.

Damage inspection

A visual inspection of the EV can be used to identify the severity of damage that the vehicle has sustained. Vehicles with only minor damage, for example, superficial damage or where the damage is well away from the HV componentry, can be recovered using the normal recovery techniques.

Vehicles that have sustained major damage could have unstable battery systems and may require the attendance of the emergency services. The risk assessment presented in Table 2 provides risk levels for different observed hazards and indicates when the emergency services should be called.

General considerations

The batteries of EVs are generally located low in the floor of the vehicle, creating a low centre of gravity. If an EV is lying on its side, it may be more unsteady than an equivalent internal combustion engine vehicle in a similar position. Always be wary that a vehicle may topple until it is stabilised to prevent movement. The vehicle should not be allowed to drop to the floor if it is on its side and any movement or lowering should be controlled so that the battery is not compromised.

Before recovery of the vehicle, always check that the vehicle systems have been switched off. Because EVs operate very quietly, it may not be evident that the vehicle is still operational.

A and F: assess and formulate

Use the knowledge and observations from the study to assess any potential hazards and determine the dangers that these may present during the recovery operation.

As well as the normal hazards associated with any vehicle recovery operation, you should also consider those specific to EVs. Electrical hazards may exist due to the HV systems on a crash-damaged EV. There may also be chemical hazards or the risk of a thermal runaway if the battery has been damaged or been involved in a fire. Table 2 can help to assess what level of competence is needed to deal with different hazards.

When the situation and the potential hazards that may exist are understood, a recovery plan can be finalised to ensure that it can be completed safely and will not cause any additional dangers. Enough information should be collected to decide if help from the emergency services is required. If additional help is needed, secure the area, and await help before starting any recovery operations.

Electrical hazards

The HV systems on an EV are completely isolated from the chassis of the vehicle. There are many protection systems in place to monitor for any hazards and to switch off the HV system if an incident occurs. However, there is currently no requirement for vehicles to have an indicator to show if the HV systems have been deactivated.

If the vehicle airbags have been activated, then this is a good indicator that the HV systems should be inactive. However, an electrical hazard could exist if any HV components or cables have been damaged or exposed in a serious incident. The ERG or mobile phone apps can be useful in discerning if any HV components could have been damaged. The initial vehicle study should identify any areas of possible danger.

Before commencing any recovery operation, remote keyless operation fobs should be placed in a signal-blocking pouch to avoid them initiating any HV systems. Also consider the potential of smart phone apps which may also interact remotely with the vehicle systems. These may also need to be placed in a signal-blocking pouch.

If necessary, and with suitable prior training, the low voltage (LV) systems on the vehicle may be disconnected prior to vehicle recovery. For most vehicles, disconnecting the LV supply (12V/24V) will also deactivate the vehicle HV systems because it removes power to the battery control system (which is designed to fail to a safe state). This is not true for all models of vehicles and may not be true for vehicles with damage to their HV systems. You should ensure that the LV supply cannot be inadvertently reconnected.

Disconnection of the LV system should not be undertaken if a vehicle is submerged in water. In such situation, remove the vehicle from the water before undertaking any disconnection procedure. Once the LV system has been disconnected, it may take time for the voltage to drop to a safe level.

For newer vehicles, with active discharge systems, this can take up to 15 seconds. For older vehicles without an active discharge system, this may take up to 10 minutes. HV may still be present after this period.

You should not touch HV cabling or components even after LV disconnection.

Many EVs have a means to isolate the HV systems, either through a manual service disconnect (MSD) or by cutting through a designated separation point as defined in the manufacturer’s ERG. Observations and information obtained from the ERG can be used to assess how different areas of the vehicle could be accessed to undertake these tasks in a safe manner, especially if vehicle damage could prevent access to those areas. There are some instances in which it may be appropriate to isolate the HV system in this way. These instances should be outlined in relevant training but can include examples such as the recovery of heavy vehicles and some instances where there is significant damage to the HV system. In these instances, you must ensure you are suitably trained to interact with the HV system, have the correct PPE and have established that this course of action is necessary and appropriate.

Thermal runaway: vapour cloud explosion hazard or fire hazard

Based on current statistics, the likelihood of a fire in an EV remains low, one involving the battery pack even rarer. However, the incidents can be significant when they do occur. Thermal runaway occurs when a battery becomes unstable and an uncontrolled chemical reaction causes it to overheat, often leading to a battery fire or vapour cloud explosion (VCE). This could be triggered, for example, at the roadside, by an EV driving over debris that has pierced the battery pack.

Emergency services will need to attend if a vehicle is on fire, has been on fire or there is a possibility that a fire could start. They will also need to attend if a VCE has occurred or there is a possibility of its occurrence. A VCE is a process that can occur when the vapours emitted during the thermal runaway process suddenly and violently explode. A fire to the main HV battery or a VCE is a very severe incident and should not be tackled by an untrained person. Only fire service personnel with specialist training, using self-contained breathing apparatus, should tackle these types of fires or events.

Battery fires may result in jet-like, directional flames and will release toxic chemicals, which can pose a risk to health. However, a normal vehicle fire could develop, quickly, into a main battery fire if left long enough, hence, in the event of any EV fire, defer to the fire service. Evacuate all people around the vehicle and retreat to a safe place well away and upwind from the fire and any smoke or fumes.

A VCE resulting from battery thermal runaway and can occur in both enclosed spaces (due to the build-up of gases) and in the open such as road(side). These explosions cause violent combustion and can be extremely dangerous. Before a VCE occurs, toxic gases will be released from the vehicle; these gases can vary in colour and appearance, so can be mistaken for smoke. In the event of a suspected VCE event, defer to the fire service. Evacuate all people around the vehicle and retreat to a safe place well away and upwind from any smoke, gases, or fumes.

Current industry guidance states that a vehicle at risk of going into a thermal runaway event should ideally be kept 15 metres from anything else. In a recovery scenario, this distance may not be achievable, but it should be noted that hazards such as projectiles may exist within (and in some instances, outside of) this 15-metre zone. The priority in this scenario is to defer to the fire service, evacuate all people around the vehicle and retreat to a safe place well away and upwind from the vehicle.

If a fire has started from the low voltage supply (12/24 V battery) then a suitable extinguisher can be used to aid evacuation, if appropriate.

Assessing the possibility of thermal runaway

When assessing an EV in a recovery scenario, in the event of flame or ejection of gas or other material, smell of irritating chemicals, or unexpected noises such as the loud hiss of a release of gas, abort all assessment and checks, retreat to safety and call the fire service. It should be noted that the absence of these signals, or any measured or discernible elevated temperatures, may not indicate a complete absence of thermal risk.

The location of the battery can be identified by using the ERG or other information. A non-contact infrared thermometer can be used to monitor the temperature of battery pack surface casing, provided it is accessible. Temperature measurements should be taken of the ambient air, the ground and 5 points dispersed across the accessible geometry of the battery pack casing. Photographs should be taken of the temperature recordings once they have been taken.

HV battery fires can ignite unexpectedly. When assessing a vehicle, recovery operators should not put themselves in danger, for example, do not lie on the floor beside a vehicle with a suspected HV battery condition. Monitor the battery pack casing temperature periodically during the recovery process to establish if it is stable or changing.

A battery pack which is hotter than 50°C or is experiencing a temperature increase would be detected as a corresponding rise in temperature of the (metal) casing, giving an indication that the battery pack is undergoing a thermal event. If this is observed, then stop any other actions and only monitor the HV battery casing temperature, provided it is safe to do so. If the temperature does not stabilise or reduce and is instead continuing to increase, then you should contact the fire service. It should be noted that vehicles that do not exhibit this temperature increase may still be undergoing a thermal runaway event.

Vehicle fire blankets

Emergency services personnel may deploy a fire blanket over a vehicle which is suspected of being at risk of, or undergoing, a thermal event. Fire blankets should only be deployed by vehicle recovery personnel who are trained in their use and are wearing the correct protective equipment. Fire blankets should not be used on a vehicle that is already on fire.

The fire blanket itself will not stop a battery fire, it may contain any flame and stop a fire from spreading, diminish its severity and reduce the amount of chemicals and particulates released into the surrounding environment. There is a possibility that vapours may still escape from beneath the fire blanket and therefore a VCE hazard may still exist, particularly in enclosed spaces.

Vehicle recovery operators should not attempt to remove a vehicle fire blanket after deployment. This should only be done by the fire service. There is a risk that upon removal of the blanket, the fire may re-start, toxic chemicals may be released, and sudden combustion and explosion may occur. Recovery operators are recommended to retreat to a safe location well away and upwind from the vehicle if a fire blanket has been deployed.

Loading operation

EV battery fires which have been extinguished are susceptible to reignition, especially during the loading operation – as the vehicle may be subjected to shock loads. Ensure that you monitor the HV battery condition and be prepared to respond to any incident. In these cases, the recovery operator will require fire service support. The fire service should remain on the scene and where possible, escort the recovery operator back to their yard. The vehicle should be stored away from other vehicles to mitigate the risk of a fire spreading between vehicles.

Chemical hazard

A chemical hazard could be present if the battery system has been severely damaged, is on fire, has been on fire, or is undergoing a thermal event. When a thermal event occurs, chemical gases and particulates can be released, many of which may be toxic. It is important not to attempt to deal with a vehicle in this condition without appropriate training and equipment.

When studying the scene of the incident a chemical hazard may be identified by liquids or gases leaking from the HV battery area. It is highly likely that hydrogen fluoride gas as well as other harmful compounds will be released during an EV battery fire. Hydrogen fluoride can irritate the eyes, nose and throat, and in high-enough levels can even be fatal. Stay well clear of a burning vehicle and away from any fumes, smoke or vapour.

If a vehicle has been on fire, there is a high possibility that many of the chemical residues left behind could pose a hazard to you and any bystanders. These residues may have an unusual colour or a strong acrid smell. Hydrofluoric acid is of particular concern. This can be generated by the combination of water used to extinguish a fire and hydrogen fluoride gas released from the battery during a thermal event.

Hydrofluoric acid can cause very severe skin burns, serious eye damage and must be treated immediately using copious amounts of calcium gluconate gel for at least 15 minutes. Ensure any person contaminated receives medical assistance as soon as possible. When moving an EV that has been involved in a fire, it is always recommended to wear suitable gloves to protect against chemical hazards. You should also ensure that any bystanders and the local environment will not be contaminated by moving the vehicle.

Overall risk assessment

Table 2 gives the risk level of the recovery operation based on vehicle observations. It will help to assess the adequate level of training and knowledge required to deal with different situations as well as whether the emergency services should be engaged or not.

The recovery operation should be classed at the risk level of the highest-ranking observation seen.

For airbag deployment, another high-risk observation should be noted to class the recovery as high risk.

Table 2: Table showing risk levels for different observed hazards.

Observation	Light risk	Medium risk	High risk
Airbags	Not deployed	Deployed	Deployed and another high-risk condition observed
Vehicle structural damage	Minor or no damage	Major damage but not intruding into HV locations	Severe damage into HV locations, especially battery area
Chemical smell	No smell	No smell	Strong pungent or acrid smell that may also cause irritation to the eyes or nose/throat
Sound	No sound	No Sound	Electrical sparking, gas release hiss or popping heard
Battery temperature	Battery casing at stable temperature (with no temperature rise observed) or temperature reducing	Battery casing temperature around ambient and no temperature rise observed	Hot battery casing or increasing temperature observed
Fire	No fire	No fire	On fire or has been on fire
Smoke and gas	No smoke	No smoke	Light smoke or vapour or thick dark smoke or white/grey acrid smoke
Dashboard fault codes	No fault codes	Fault code displayed	Fault code displayed and severe damage to HV locations
Recommended recovery procedure	Normal recovery with basic EV awareness training	Normal recovery with basic EV awareness training but the situation should be actively monitored. Emergency service attendance may or may not be required.	Emergency service attendance required.

E: execute

Once a risk-based recovery plan is in place, all relevant information has been collected and any additional support has been requested, then the recovery process can commence. Always ensure that the recovery operation progress is monitored and respond to any issues that may occur.

An unstable HV battery can ignite unexpectedly. Regular monitoring of battery temperatures and prompt response to assess any unusual sounds or smells will provide additional time to react. This could be critical in enabling a reassessment of the situation and to understand if the vehicle recovery operation risk level has changed and poses a higher danger to operators or any bystanders.

When moving a vehicle, any shock loads or body movement should be minimised. These may exacerbate any internal damage to the HV battery system that may not have been apparent from the initial visual inspection. There have been reported instances of vehicles igniting during the loading operation.

If conditions change and it is believed that risk levels have increased, then consider requesting support from emergency services, especially if evidence suggests that a vehicle fire or thermal event could occur.

Handover

If there is a need to handover the EV to the emergency services, passing on all the information gathered will help them with their own assessment.

If receiving the vehicle, for example during a handover from the emergency services, obtain all information that may be needed to complete work in a safe manner. This may include, for example, details regarding whether systems have been isolated, or the incident has affected the battery pack.

If there is no direct handover to allow information to be exchanged, then a full assessment of the scene should be made to confirm that there is no danger to the recovery operators and that the condition of the vehicle has not changed since the previous personnel left.

More guidance on the handover information can be found in the IVR EV/Hybrid Protocol document.

Towing or moving an EV

It is not recommended to tow EVs on their wheels because this can generate electrical current and damage the HV systems. The recommended method of transportation is on a flatbed or trailer, or by using dolly wheels, but the manufacturer’s instructions or ERG should always be referred to for further information.

Some vehicles, HGVs and buses, for instance, may have some means by which the drive axles can be disconnected from the electric motors to allow them to be safely towed on their wheels.

However, it is permitted to tow or push an electric/hybrid vehicle on its wheels a short distance out of immediate danger (for example, a live traffic lane), provided that:

• it is done so at walking pace
• the distance is kept to a minimum, to remove the vehicle from immediate danger only
• the vehicle’s transmission is in neutral and parking brake is disengaged
• the vehicle has not been involved in a road traffic collision and is not visibly damaged

Further information on towing or pushing a vehicle may be found in the owner’s manual or vehicle manufacturer’s website or in the ERG for the vehicle.

Keep up to date with new developments as there are emerging recovery systems, processes and equipment, such as freewheeling hubs and foldable trailers, which could be used to tow vehicles while preventing the drive train from turning during the recovery process.

Tunnels

If the vehicle is in a potentially unsafe state, then travel through tunnels should be avoided to prevent the risk of a serious incident. Recovery operators must also ensure that they comply with any guidelines set by the tunnel operators.

A road tunnel is defined as a subsurface highway structure enclosed for a length of 150m or more.

Storage

Just like any conventional vehicle, EVs can reignite hours or even days after an incident, although the likelihood of this happening may be higher with EVs. Isolation of the HV systems by either disconnecting the LV system or engaging the HV system manual service disconnect (MSD) is advised; refer to the vehicle ERG or manufacturers’ guidelines for additional information. Although, it should be noted that disconnecting the HV system may not stop the vehicle going into a thermal event.

When storing an EV with a suspected damaged HV system, it should ideally be in an outside quarantine area which is a suitable distance away from any other nearby objects. According to industry guidance, 15 metres is currently considered a safe storage distance between vehicles. This recommended distance may not be achievable in practice and, as such, risk assessments should be conducted to mitigate the risk of storing vehicles closer together.

Potential mitigations include temperature monitoring of vehicles, the use of fire-resistant barriers and fire blankets and using dedicated fire-protected parking areas. Consequence management should also be considered as a part of the risk assessment process. This can include measures such as evacuation plans, moving vehicles or ensuring any escape route(s) from spaces occupied by an EV that is prone to failure in storage would not be compromised.

Monitor EVs which pose a fire risk for up to 48 hours after an incident. If the HV battery temperature does not drop to ambient temperatures, then leave the vehicle in its safe quarantine location. EVs whose battery temperatures do stabilise can be stored closer together; current recommendations are that a 2-metre gap is still provided to allow access around the vehicle for inspection purposes.

There have been some instances of vehicles igniting up to 3 weeks after an accident due to internal damage caused during the incident, which may result in a slow or delayed thermal event. This could be caused by additional movement of the vehicle around a storage area or by an internal fault such as coolant leakage, ingress of water from the environment or coolant drying out leaving behind conductive material. This potential hazard can be reduced by inspection of the vehicle and periodically measuring the battery temperature to establish that the condition of the battery is not changing during storage. Remote temperature sensors that constantly monitor and send a warning to a mobile device can be used to, effectively, protect against this hazard.

EVs stored outside, especially those with major damage exposing HV locations, should be covered with a weatherproof tarpaulin to protect against exposure to the elements.

If EVs need to be stored for prolonged periods of time, and it is possible to do so, arrangements should be made for a technical specialist to remove the HV battery pack at the earliest opportunity and ensure it is stored, or disposed of, appropriately. The vehicle can then be stored in the usual manner with no other additional safety measures amongst conventional vehicles.

It should be noted that in some instances the disconnection of the LV system, the removal of the MSD or the removal of the battery may not be appropriate, for example, storage of vehicles by the Police for investigative purposes. In these instances, and where appropriate, the other recommendations of this section should be followed.

It is recommended that for EVs in storage, the safety level of the vehicle is displayed to inform people who work in the area. Best practice would be to use the industry standard traffic light colour-coded safety status signage to identify the risk level of vehicles as follows:

Red

Danger, vehicle is unstable and/or an HV hazard exists. If the vehicle has potentially exposed live parts, it should be secured in some way to prevent access, for example, by using a barrier to create an exclusion area or storing in a secure area.

Amber

Active, vehicle is stable, but the HV system is active and operational. There is some hazard.

Green

Safe, vehicle is stable and the HV systems have been isolated.

Figure 1: Examples of vehicle safety status colour coded signs.

Alternative markings, with clear interpretation, can be used to display the safety level of the vehicle, for example, labelling – which indicates the vehicle is an EV and/or the thermal history of the vehicle. The recovery industry also have stickers that are used to specify an EV and to record battery temperatures.