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A major risk to life, limb and property - lies hidden in plain sight

Are you aware of the risks that commonly used devices in homes, workplaces, on our dives and garages now pose?

Laptop computers, electric bikes, e-scooters, drones, toys, power tools, battery storage systems and cars – they all have one thing in common: lithium-ion (Li) batteries.

Few of us realise the deadly potential these devices pose. The toxic gas, explosion and ferocious flame potential batteries of this type create when they become overheated or when they sustain damage is rarely understood.

Thermal Runaway

Batteries in these conditions result in a chemical reaction occurring, known as “thermal runaway”. It’s an unstoppable cycle of smoke, explosion and flame.  It produces massive clouds of heavier and lighter than air toxic gas, in volumes way out of all proportion to the size of the battery, usually accompanied by a loud explosion and shooting ferocious flames, which are almost impossible to extinguish.

What’s more, such a battery - after sustaining damage, for example when an electric car (EV) runs over an object - can sit for hours or even days before a searing chemical reaction occurs. If this happens inside a building car park for example, or when an on-charge e-scooter battery becomes overheated inside a house, the result can be a catastrophic poisonous gas cloud, a loud explosion and the whole fire. This happens in seconds, and if the scooter on-charge happens to be in a main escape route, tragic consequences are almost inevitable.

More and more devices use Li batteries

The use of appliances with Li batteries today is proliferating: from these e-scooters and e-bikes to electric vehicles (EVs), their public use is steadily growing in the UK.

While reducing the number of fossil fuel burning cars on the roads is arguably taking us a stage nearer net zero, one unintended consequence has been the growing number of life-threatening fires caused by faulty lithium-ion batteries. 

At least two multi-story car parks have gone up in flames, destroying the structure along with most of the vehicles inside, and several deaths have been reported attributed to overheated e-scooter batteries.

The threat is real and quite alarming

The London Fire Brigade was reportedly called out to at least one e-scooter fire every two days last year. EV fires have been attended 239 times as recorded in the UK from July 2022 to June 2023, all incidents linked to EVs, and at least one large car carrying ship is thought to have succumbed and sunk due to a fire caused by its EV cargo.

Of course, we shouldn’t exaggerate this risk. Of the many thousands of EVs on the road the number of incidents is small and apparently, we are told, the risk is significantly less than that of a petrol or diesel car catching fire. But when it does happen these fires are difficult to deal with.

Incidence is low

Insurance studies tell us that EV fires are a lot less likely than petrol or diesel fires. One Swedish Civil Contingencies Agency claims that EVs are 20 times less likely to catch fire than petrol and diesel cars, corroborated by a US insurer that found EVs suffer 25 fires per 100,000 sold, while petrol or diesel vehicles were found to experience 1,530 fires per 100,000, with hybrid vehicles at a notably higher risk of 3,475 fires per 100,000​​​​.

But when an EV event does occur, the results are often more serious, they cause more damage and are far more difficult for firefighters to deal with given the ferocious fires and the release of toxic gas that ensues.

The numbers may be smaller, the consequences are higher

Given the risk, building owners, landlords, agents, contractors and building designers need to start working on systems, particularly in relation to high-density residential buildings, to consider if they are taking adequate measures to reduce these risks.

Is it safe to allow the charging of e-scooters and e-bikes inside a residential property? Are car parks in residential building basements safe when EVs are parked there overnight? These issues raise serious concerns for the residents, for landlords and for the authorities.

Building safety

Employers as well as building owners have a general duty under the Health and Safety at Work Act 1974, the Regulatory Reform (Fire Safety) Order 2005, and landlords of houses in multiple occupation (HMOs) and covered under The Management of Houses in Multiple Occupation (England) Regulations 2006 and the Landlord and Tenant Act 1985. 

These responsible persons must ensure that people are not exposed to risks to health and safety and must take general fire precautions to ensure that the premises are safe. In high-rise buildings, the relevant “Accountable Person” must prevent a building safety risk from materialising, and to mitigate the effect should a risk arise. 

Such are the risks with these devices that building owners and employers are already starting to become aware of them and doing something about it. The best solution of course is to remove the risk altogether by banning all such vehicles and appliances from being used inside residences, to keep them in the open air where they can do little harm, an ideal that’s clearly impractical.

Users need to be educated

From the landlord’s point of view the risk is real and tenants need to be educated about these risks, especially in multi-occupied and high-rise buildings. An e-scooter left on-charge in a hallway could prove deadly if the battery is damaged or overheats.

Buildings need to be designed with these devices and EVs in mind. Existing buildings need to be modified or facilities provided so that they can be stored securely and charged safely. For example all e-scooters and e-bikes should be kept in secure storage outside of buildings. All car parks within buildings must meet stringent fire safety standards. 

Here is some useful information provided by The London Fire Brigade:

A building owners and employers should:

  • Avoid storing/charging devices on escape routes or in communal areas. Safe, secure external storage areas with charging facilities should be provided. 
  • Regular inspections and risk assessments should ensure that these rules are followed.
  • Residents should be reminded to follow the manufacturer’s instructions when charging devices. 
  • Batteries should not be charged at night or left charging after being fully charged, and sockets should not be overloaded. 
  • Batteries should not be charged near combustible or flammable materials.
  • Smoke alarms should be fitted in areas where e-bikes, e-scooters and EVs are being charged, and they must be tested regularly.

The use of e-bikes and e-scooters as well as EVs is very much on the rise. Building owners, landlords, managing agents and employers should be aware that these types of appliances pose a serious risk. If in any doubt seek advice from your local fire and rescue service. 

Prof. PAUL CHRISTENSEN Electric Vehicle Battery Fires   SUBSCRIBE NOW

Prof. Paul Christensen, through research under the Faraday Institution projects seeks to inform first responders of the risks and hazards of lithium-ion batteries and hence (hopefully) to avoid injuries when dealing with Li fires and explosions involving (principally) electric vehicles and battery energy storage systems. Christensen is the Senior Advisor to the National Fire Chiefs Council and serves on a number of UK Government and British Standards Institute working and governance groups. He is the recipient of 2022 Motorola Foundations


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