They are everywhere in our daily lives: smartphones, laptops, e-cigarettes, smart speakers…
But also in the industrial world: construction machinery, electric vehicles (cars, scooters, bikes…), solar systems, data centers, power tools, and logistics sites.
It is a highly efficient technology.
A lithium-ion battery can store 3 to 4 times more energy than other technologies, charges quickly, and withstands a large number of charge-discharge cycles.
However, it is also more fragile and presents specific risks, particularly the risk of sudden ignition.
So much so that the 3rd edition of ISO 3941 norm, published in January 2026 on fire classification, introduced a new class:
Class L, dedicated to lithium-ion battery fires, also known as “electrochemical” fires.
These fires present specific hazards:
- extremely high energy density,
- thermal runaway,
- massive release of toxic and corrosive gases,
- electrolyte leakage.
The fire scenarios are therefore radically different from conventional fires.
They cannot be controlled with traditional extinguishing methods: the fire is self-sustaining, even without oxygen, and the risk of re-ignition is high.
This new “L” classification is more than just another label.
It acknowledges the unique nature of lithium-ion battery fires and prescribes appropriate management measures, both human and technical, to anticipate risks rather than endure them.
Written by Stéphanie Luttringer