Total Safety Solutions

08/03/2026

03/03/2026

Class L is a newly established fire classification specifically for Lithium-Ion battery fires.
This classification was formally introduced in January 2026 by the International Organization for Standardization (ISO) under the updated ISO 3941:2026 standard.
Key Characteristics of Class L Fires
Unlike traditional fires, Class L fires are defined as electrochemical fires rather than electrical (Class E) or metal (Class D) fires.
Their unique dangers include:
 Thermal Runaway: A self-sustaining chemical reaction that generates extreme internal heat.
 Internal Oxygen Generation: The battery generates its own oxygen as the cathode decomposes, meaning it can continue to burn even if smothered or in a vacuum.
 Re-ignition Risk: Batteries can appear extinguished but may reignite hours or even days later if not sufficiently cooled.
 Toxic Gas Release: These fires emit hazardous fumes, including hydrogen fluoride (HF).
Extinguishing Class L Fires
Traditional extinguishers (CO2, Dry Powder, Water & Foam) are often ineffective or only tackle the surface flames without stopping the internal reaction.
Specialist solutions now labelled for Class L include:
 F-500 Li-Ion Solution: An agent that penetrates the battery to rapidly remove heat and control the reaction.

01/03/2026