Big Update in Fire Safety

KOUZON FIRE & RESCUE TRAINING CENTER

Class L is Here

The International Organization for Standardization (ISO) has officially released the third edition of ISO 3941:2026 Classification of Fires, introducing Class L, a dedicated fire classification for lithium-ion battery fires. This update represents a significant advancement in global fire safety by formally recognizing lithium-ion battery incidents as a separate fire category.

Previously, lithium-ion battery fires were generally managed under traditional classifications such as Class A or Class B. However, increasing use of lithium-ion batteries in electric vehicles, energy storage systems, and electronic devices has highlighted the need for a distinct classification due to their unique fire behaviour.

Why This Matters

Lithium-ion battery fires involve thermal runaway, which generates extreme heat and can continue burning internally even after surface flames are controlled.

These fires have a high risk of re-ignition and may release toxic and flammable gases.

Rapid expansion of EV and battery storage infrastructure has significantly increased such fire risks globally.

The new classification supports improved risk assessment, emergency response planning, and fire protection system design.

Extinguishing Approach

Although a universally standardized "Class L extinguisher" is still under development, suppression strategies primarily focus on:

Intensive cooling using water-based or specialized agents

Preventing propagation between battery cells

Controlling vapor release and re-ignition risks

Future Outlook

The introduction of Class L is expected to drive updates in fire safety standards, extinguisher testing protocols, and industrial safety regulations. It will also support

fire safety standards, extinguisher testing protocols, and industrial safety regulations. It will also support development of advanced suppression technologies specifically designed for lithium-ion battery hazards.