The ISO 3941:2026 standard introduces fire class L, dedicated to lithium-ion batteries. A major step forward given the growing risk these fires pose in professional environments.
Why a new class?
Li-ion fires behave unlike any other:
- Rapid thermal runaway
- Re-ignition possible hours after initial extinguishing
- Toxic gases and extreme temperatures (>1000°C)
- Extinguishing can be complex, sometimes requiring thousands of litres of water
Conventional extinguishers are insufficient. A dedicated class was needed.
What does Class L cover?
Only lithium-ion battery fires (not metallic lithium).
Does not cover solid (A), liquid (B), gas (C), metal (D), or cooking oil/grease (F) fires.
Extinguishing methods:
- Massive water cooling
- Prolonged immersion
- Li-ion specific agents (in development)
- Post-fire monitoring mandatory
Impact on workplaces: training & risk assessments
Class L changes the game:
- Fire training must be updated
- Emergency procedures revised
- Charging and storage areas secured
- Risk assessments (RA / DUERP) updated to include “Li-ion Fires – Class L”
Where is the risk?
Virtually everywhere:
- E-bikes and e-scooters
- Power tools
- Cleaning robots
- Smartphones, laptops, tablets
- Electric vehicles
- Energy storage cabinets
- Batteries and cells
Prevention and training are now essential. Class L isn’t just another regulation – it’s a paradigm shift in fire safety.
