Class L Fire Classification: What Lithium-Ion Battery Fires Mean for Fire Safety

Fire safety standards are constantly evolving to keep pace with new technologies, materials, and risks. One of the most significant recent developments is the introduction of a new fire classification – Class L, which specifically covers lithium-ion cell and battery fires.

As lithium-ion batteries are now commonplace across homes, workplaces, vehicles, and industrial settings, this new classification marks an important shift in how fire risks are identified, assessed, and managed. In this article, we explain what Class L fires are, why they matter, how fire risk assessments are changing, and how the LFX extinguisher plays a vital role in addressing this growing hazard.

What Is a Class L Fire?

Class L is a newly introduced fire classification designed specifically for lithium-ion cells and battery fires. Unlike traditional fire classes (A, B, C, D and F), lithium-ion battery fires behave in ways that make them particularly dangerous and difficult to control.

Lithium-ion batteries can enter a state known as thermal runaway, where internal temperatures rapidly increase, causing the battery to ignite, explode, or re-ignite multiple times. These fires can burn intensely, release toxic gases, and continue even after initial flames appear to be extinguished.

This unique behaviour means that lithium-ion battery fires cannot be treated as “standard” electrical or combustible fires. The introduction of Class L formally recognises this risk and ensures it is assessed and managed correctly.

Why Lithium-Ion Battery Fires Are a Growing Concern

Lithium-ion batteries are now everywhere. They are used in:

  • Mobile phones, laptops, tablets and power banks

  • E-bikes, e-scooters and electric vehicles

  • Cordless power tools and garden equipment

  • Energy storage systems and backup power supplies

  • Medical equipment and industrial machinery

As usage increases, so does the risk. Battery damage, incorrect charging, overheating, poor storage, manufacturing defects, or ageing can all trigger a lithium-ion fire.

What makes these fires especially dangerous is that:

  • They can ignite without warning

  • They can re-ignite hours or even days later

  • Water alone may not stop thermal runaway

  • They release toxic and flammable gases

  • They can spread fire rapidly to nearby materials

The introduction of Class L is a clear response to these realities.

How Fire Risk Assessments Are Changing

With the introduction of Class L, fire risk assessments are evolving. When a property risk assessment is carried out, assessors will now also comment specifically on the presence and risk of lithium-ion batteries within the premises.

This means assessors will consider:

  • The type and quantity of lithium-ion batteries on site

  • How and where batteries are stored

  • Charging locations and practices

  • Whether damaged or end-of-life batteries are present

  • The potential impact of a battery fire on occupants, assets and escape routes

For many businesses, this will be the first time lithium-ion battery risks are formally highlighted in their fire safety documentation. This applies across a wide range of sectors, including offices, warehouses, workshops, residential buildings, retail premises and transport facilities.

Where a Class L risk is identified, appropriate control measures and firefighting equipment will be recommended.

Introducing the LFX Extinguisher for Class L Fires

To address this new classification, the LFX extinguisher has been developed and is now being supplied specifically for lithium-ion cell and battery fires.

The LFX extinguisher is designed to:

  • Cool the battery effectively

  • Suppress flames while limiting re-ignition

  • Reduce the spread of fire to surrounding materials

  • Help control thermal runaway more safely than traditional extinguishers

Unlike standard extinguishers, which may be ineffective or even unsafe when used on lithium-ion battery fires, the LFX extinguisher is purpose-built for this risk category.

Where a fire risk assessment identifies lithium-ion batteries as a hazard, the inclusion of an LFX extinguisher provides a clear, practical and compliant response.

Who Needs to Be Aware of Class L?

Class L fire risks are not limited to industrial or high-risk environments. Many everyday premises now fall into this category, including:

  • Offices with laptops, phones and battery charging stations

  • Warehouses storing battery-powered equipment

  • Workshops using cordless tools

  • Residential blocks with e-bikes or scooters

  • Commercial premises with energy storage systems

  • Transport and logistics facilities

If lithium-ion batteries are present, even in small quantities, the risk exists and should be assessed properly.

Staying Ahead of Fire Safety Compliance

The introduction of Class L reinforces an important point: fire safety is not static. As technology changes, so must the way risks are identified and managed.

By recognising lithium-ion battery fires as a distinct class, fire safety professionals, duty holders and property managers are better equipped to:

  • Understand emerging risks

  • Put appropriate controls in place

  • Select the correct firefighting equipment

  • Protect people, property and business continuity

Fire risk assessments that include Class L considerations are not about creating unnecessary concern – they are about ensuring preparedness in a world where battery technology is now embedded in daily life.

Expert Support for Modern Fire Risks

At Fire Extinguisher Maintenance, fire safety solutions are aligned with the latest standards, classifications and real-world risks. As fire risk assessments begin to highlight Class L hazards more frequently, the availability and correct placement of LFX extinguishers will become an increasingly important part of responsible fire safety management.

Understanding Class L today means being better protected tomorrow.