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FEATURE ARTICLE

18 October 2022

Electric vehicle safety

There are around 456,000 zero-emission battery EVs on the UK’s roads. According to estimates from the RAC, in the region of 77,000 EVs were registered in 2022 alone, along with over 348,000 plug-in hybrids. With no new petrol and diesel cars and vans to be sold in the UK after 2030, and with hybrid sales banned from 2035, the push to get drivers into cleaner vehicles is now stronger than ever.

Types of vehicles include:

  • Electric vehicles: EVs use a large capacity battery and electric motor(s) to drive the vehicle. The battery needs to be charged from the electricity supply network when the vehicle is not in use, although some energy may be recovered during braking.
  • Hybrid vehicles: typically, hybrid vehicles have two sources of energy – an internal combustion engine using either diesel or petrol for fuel and a battery. Hybrid vehicles will use the two sources of power automatically and may use both simultaneously. The internal combustion engine and energy recovered from the vehicle’s braking systems are used to charge the battery.

The emergence of EVs has led to a number of unique safety concerns, not least those around fire and explosion. The main danger occurs when the lithium-ion battery is damaged. This might happen if it is exposed to extreme heat or if something penetrates the battery cell wall. Risks around charging and electricity associated with high-voltage circuits and batteries must also be considered.

Important areas to think about include:

  • Selecting and designing areas for use – electric charging points must be considered as part of a fire risk assessment for a premises.
  • When identifying sites for charging points, sufficient space must be available for vehicles so that they can be parked safely in the designated charging area, and for a connection to be made to the charging equipment.
  • Space must be sufficient to enable other vehicles to be manoeuvred around charging vehicles safely.
  • Staff should be trained in the safe use of chargers for vehicles.

Legal requirements

Whilst there is no specific workplace health and safety legislation that specifically applies to EVs, the general requirements of Sections 2 and 3 of the Health and Safety at Work etc. Act 1974 apply to employers in respect of ensuring, so far as is reasonably practicable, the health and safety of employees and those not in employment who may be affected by the activities of the employer.

In premises where the Regulatory Reform (Fire Safety) Order 2005 (or equivalent legislation in Scotland and Northern Ireland) applies, the fire safety management strategy should consider practical passive, active, and managerial control measures as part of the fire risk assessment for the premises when selecting and designing areas for use as electric charging points.

The assessment should also include the suitability of the location for charging and the nature of the equipment for the intended purpose, since it must be installed in the immediate vicinity of vehicles.

In addition, the Provision and Use of Work Equipment Regulations 1998 are applicable to a vehicle used at work, and in respect of electrical safety in relation to work, the Electricity at Work Regulations 1989 apply both to the electrical safety of the vehicle and of any associated charging equipment or infrastructure.

EV charging and use

Fire and the electrical risks associated with charging means extra consideration needs to be given to ensure employees who are provided with EVs, maintain them, or who drive them for work, are informed of the particular issues.

Reducing damage to a lithium-ion battery will significantly reduce the chance of fire.

Fires

The lithium-ion batteries used for powering EVs can be liable to damage through overheating. The electrolyte liquid contained in lithium-ion batteries is flammable and can burn at extremely high temperatures, releasing large amounts of toxic gas. The intensity of the fire, combined with the relatively lower experience rescue teams have with EVs, means that such fires can take a long time to extinguish.

Reducing damage to a lithium-ion battery will significantly reduce the chance of fire. Avoid keeping batteries in hot vehicles, overcharging, and fast charging, as these can all destabilise the battery and increase the risk of explosion. A shutdown separator can be used as an additional layer of protection for the built-in shutdown mechanisms in lithium-ion batteries. Regularly monitoring the cooling system, and ensuring good maintenance, will help to keep temperatures down both when driving and charging and reduce the risk of explosion or fire.

Electric shock

The high voltages needed to charge EVs leave users vulnerable when charging their vehicles when plugging, unplugging, and handling cables. Damage to cables and charging equipment, cable chaffing, and weather conditions, can increase the existing risk of electric shock.

Basic maintenance of cable insulation, plugs, and wiring can significantly reduce the risk of electric shock at charging stations. All components should be regularly checked before activating the charger or plugging it into a vehicle. Employees should also be instructed on what to do if someone receives a high-voltage electric shock. At public charging stations, any accident or damage to equipment should be immediately reported to a member of staff.

Maintenance and repair

The HSE advises that remote operation keys should be kept away from the vehicle to prevent any accidental operation of electrical systems and accidental movement of the vehicle. Keys should be locked away with access controlled by the person working on the vehicle. If the key is required during the work, the person working on the vehicle should check that the vehicle is in a safe condition before the key is retrieved.

EVs should be visually checked for signs of damage to high-voltage cabling (usually coloured orange) or electrical components before starting any work on the vehicle. Unless a specific task requires the vehicle to be energised, the high-voltage battery should always be isolated or disconnected in accordance with the manufacturer’s instructions.

The locations of high-voltage cables should be located before carrying out tasks such as panel replacement, cutting, or welding. And appropriate precautions should be taken to prevent them from being damaged.

Employees should be briefed on the particular requirements for jacking the vehicle in the event of a breakdown or tyre replacement (whether by themselves or service personnel) to avoid causing damage to the battery. Such damage may also result in fire risk.

Reducing the risk

The powerful voltages needed to charge and operate EVs present hazards that must be managed safely, and these are additional hazards to those normally associated with vehicles. These include:

  • the presence of high-voltage components and cabling capable of delivering a fatal electric shock
  • the storage of electrical energy with the potential to cause an explosion or fire 
  • components that may retain a dangerous voltage even when a vehicle is switched off
  • electric motors or the vehicle itself that may move unexpectedly due to magnetic forces within the motors
  • manual handling of risks associated with battery replacement
  • the potential for the release of explosive gases and harmful liquids if batteries are damaged or incorrectly modified
  • the possibility of people being unaware of vehicles moving due to silence in operation
  • the potential for the electrical systems on the vehicle to affect medical devices such as pacemakers.

Risk assessments should consider fire risks from charging EVs. Measures to consider should include:

  • physical segregation of the charging areas from the process and storage areas
  • provision of suitable power supply, control, and isolation systems that will allow isolation of the charging points from a safe location without having an impact on business production and process functions
  • suitable automatic fire detection and warning installations in the case of fire 
  • provision of portable firefighting equipment, together with fixed fire suppression systems where the latter may be proportional to the risk
  • development of an emergency action plan to protect life and property, and ensure the continued functioning of the business in the case of fire
  • staff training in the safe use of charging equipment and the actions to take in the event of fire, including the safe isolation of power from the charging station and evacuation of the premises.

Extra consideration should be given to situations where premises are unoccupied. In commercial premises where the batteries of EVs are charged, the fire hazards are increased by the need for the charging process to continue during the night or over weekends, when very few or no staff are present. Attention to all fire and safety implications when charging areas are being selected and designed is, therefore, crucial.

Fires from EV batteries and charging

Recent research shows that most EV fires result in the complete loss of the vehicle, with e-scooters and electric cars accounting for the majority of EV fires.

According to the London Fire Brigade (LFB), there have been 57 e-bike-related fires in London so far this year. This is an increase in the 47 fires of last year, 13 in 2020, and 10 in 2019. Examples include a large tower block fire in June 2022, which was started by an e-bike battery malfunctioning as it charged; a man who escaped without serious injury from a blaze at his flat after his electric bike battery caught fire while it was on charge; and the recent tragic death of a man in Bristol, who fell after climbing out of a top-floor flat as he fled a fire that was caused by an electric bicycle in the hallway.

Subsequently, LFB’s fire investigation team has encouraged people who use these products to be aware of the risks and highlighted the danger of storing them in escape routes in the home or in communal areas such as hallways in blocks of flats.

An investigation by consumer safety charity Electrical Safety First found some 59 dangerous e-bike chargers were on sale via popular online marketplaces. The investigation noted that many plugs failed to contain a fuse, creating a serious risk of fire if there was a fault with the supply lead. Other defects included dimension issues, leaving users at greater risk of an electric shock, leading to calls for a ban on these dangerous e-bike chargers.

 

Barbour is the oldest provider of specialist information services to industry professionals.

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