Assessing Fire Risks: Are Electric Cars More Prone than Petrol or Diesel Vehicles?


A recent fire at Luton airport sparked speculation of an electric vehicle causing it, but the Bedfordshire fire service clarified it originated in a diesel car. Despite this, the rumor persisted on social media, becoming a resilient “zombie myth” that defies debunking.

Electric vehicles (EVs) are seen as pivotal in transitioning from fossil fuels, although they alone won’t entirely mitigate environmental damage. The Guardian, consulting experts and data, aims to debunk common criticisms of EVs in a series of articles. The inaugural piece addresses concerns about fires in electric cars, exploring myths, realities, and grey areas in this aspect.

The claim

Concerns about electric car fires revolve around two main categories: the perception that fires are more frequent in electric cars and the belief that, when they occur, the damage is more severe. If electric cars indeed present a higher fire risk than their petrol or diesel counterparts, potential consequences may include the need for larger parking spaces to prevent fire spread. Additionally, there’s a suggestion, as raised by Conservative MP Greg Smith, that EV owners might face higher insurance premiums to offset added costs to firefighters, highlighting the broader implications of such considerations.

The science

As millions of electric cars populate global roads, emerging data, albeit fragmented, indicates that there’s no substantial evidence to suggest electric vehicles are more prone to fires. Contrary to concerns, several experts suggest that, if anything, electric cars demonstrate a lower likelihood of catching fire compared to traditional vehicles.

“All the data shows that EVs are just much, much less likely to set on fire than their petrol equivalent,” said Colin Walker, the head of transport at the Energy and Climate Intelligence Unit thinktank. “The many, many fires that you have for petrol or diesel cars just aren’t reported.”

Fires in electric cars can stem from various causes. In electric vehicles, thermal runaway, triggered by cell penetration or manufacturing errors leading to short circuits, can initiate unwanted chemical reactions. This process causes rapid heating of battery cells, releasing toxic and flammable gases. In petrol cars, fires can result from electrical faults causing sparks or engine overheating due to cooling system faults, potentially igniting flammable fuel. Understanding the distinct mechanisms sheds light on the complexities associated with fire risks in both electric and traditional vehicles.

In Norway, boasting the highest percentage of electric car sales globally, data from the Directorate for Social Security and Emergency Preparedness reveals between four and five times more fires in petrol and diesel cars. The Swedish Civil Contingencies Agency’s 2022 findings show 3.8 fires per 100,000 electric or hybrid cars, compared to 68 fires per 100,000 cars across all fuel types. It’s worth noting that the broader figures encompass arson, complicating direct comparisons between electric and conventional vehicle fire rates.

Australia’s Department of Defence funded EV FireSafe to investigate the matter, revealing a minimal 0.0012% likelihood of a passenger electric vehicle battery catching fire, in stark contrast to the 0.1% chance associated with internal combustion engine cars. Unfortunately, the UK’s Home Office was unable to provide comparable data on the subject.

Tesla, led by Elon Musk, holds the title of the world’s largest electric car manufacturer. Tesla asserts that the incidence of fires involving its vehicles from 2012 to 2021 was 11 times lower per mile compared to petrol or diesel cars on US roads, emphasizing a notable safety record for its electric vehicles.

Any caveats?

Concerns about the fire risk in electric cars are heightened when witnessing the intensity of incidents in videos. Paul Christensen, a Newcastle University professor specializing in electrochemistry, emphasizes the alarming risks, including “vapour cloud explosions and rocket flames,” associated with the release of gases during battery cell events. The vivid imagery underscores the perceived severity of potential fire incidents in electric vehicles.

Paul Christensen notes that the reputation of electric cars is unfairly impacted by issues with their lithium-ion counterparts. His concerns extend to electric scooters and bikes, particularly those from unregulated or inexperienced manufacturers. Christensen advises against leaving scooters charging indoors unattended. Firefighters face challenges with battery fires, requiring more water, burning hotter, and having a higher risk of reignition, as highlighted by EV FireSafe. Some fire departments have explored immersing electric cars in water tanks as a potential solution to these unique challenges.

The verdict

While battery fires in electric vehicles pose heightened dangers, the overall probability of being involved in an EV fire seems lower than for petrol or diesel cars, according to current data. However, as electric car adoption grows, this landscape could evolve.

Walker suggests the possibility of increased EV fires as battery age rises but emphasizes that, currently, such incidents would need to multiply significantly to surpass the fire risk associated with internal combustion engines.