Lithium battery fires: From extinguishment to containment

Lithium battery fire containment is changing firefighting strategies as thermal runaway risks drive demand for certified EV fire blankets

The rapid global transition toward electrification has rewritten the rules of risk management. For decades, the core tenets of commercial and municipal fire safety have relied on a predictable playbook: rapid detection, immediate evacuation and swift suppression.

Success has traditionally been measured by the speed at which a fire is completely extinguished. However, the widespread integration of lithium battery technology presents a scenario that defies conventional firefighting methodologies. For site operators, fleet managers and emergency services, this shift requires an evolution in mindset.

When dealing with lithium batteries, the objective must frequently pivot from the traditional concept of instant extinguishment and focus on tactical isolation and environmental containment.

Understanding lithium battery thermal runaway

To understand why the response must change, one must look at the physical limitations of standard suppression agents against a compromised lithium cell stack. When a battery pack enters thermal runaway the exothermic reaction generates its own oxygen and toxic, flammable vapours, including hydrogen fluoride and carbon monoxide.

Traditional firefighting tactics rely on removing oxygen or applying large volumes of water to cool the fuel source.

In modern EVs or industrial equipment, the cells are housed within heavily armoured, weather-sealed structural casings beneath the floorpan or deep inside the chassis. This design protects the battery during daily use, but it also acts as a physical shield against external suppression agents.

Water applied to the exterior of the vehicle or casing often cannot reach the cell in the early stages of an incident. Furthermore, applying thousands of litres of water over a long time poses operational and logistical challenges.

It creates vast quantities of toxic chemical runoff, which threatens local drainage infrastructure and creates environmental liabilities for the site operator. There is also the persistent hazard of “stranded energy.”

The challenges of lithium battery fires in built environments

These incidents become especially challenging when they occur within confined or built environments. Here, a localised thermal runaway event can quickly escalate into a catastrophic multi-asset emergency.

Low ceiling clearances and restricted entry points frequently constrain standard fire apparatus from accessing the immediate site of the fire. The physical layout means assets are positioned in proximity, drastically increasing the risk of lateral fire spread.

If a battery fire is left unmanaged while emergency services are en route, the rapid build-up of toxic gas clouds and extreme temperatures can cause flashovers to adjacent assets and compromise the structure of the building itself. Therefore, the priority must be the immediate isolation of the affected asset to help protect people, nearby assets and surrounding infrastructure.

EV fire blankets and the rise of lithium battery fire containment

As the industry recognises the necessity of containment, the demand for fire limitation blankets has surged. A specialised fire blanket covers a compromised vehicle or device, suppressing flame spread, limiting smoke migration and shielding surrounding property from intense heat.

However, the rapid growth of this market created a secondary vulnerability: a lack of uniform, specialised regulation. For years, the procurement of vehicle fire blankets operated in a regulatory grey area. Buyers evaluated products based on material certifications derived from standard building textile tests. While these classifications verify the base fabric’s flame retardancy under controlled laboratory conditions, they fail to account for the extreme, dynamic physical stresses encountered during a real-world vehicle emergency.

An ineffective or uncertified blanket introduces severe operational risk. Under the pressure of a localised jet-like flame blast from a failing cell, inferior seams can split. If the material lacks sufficient structural integrity, dragging the heavy textile over a jagged, collision-damaged vehicle chassis can cause immediate tearing, rendering the containment strategy useless and exposing operators to direct heat and toxic gases.

DIN SPEC 91489: The new standard for EV fire blankets

The introduction of the standard DIN SPEC 91489:2024-11 marks a pivotal point for the fire safety sector and represents the first dedicated, regulated testing framework specifically designed for fire limitation blankets used on electric vehicles.

Rather than relying on marketing claims or textile classifications, the standard subjects the finished product to rigorous testing protocols designed to replicate a live thermal runaway event: Thermal resistance: The blanket fabric must withstand sustained temperature cycles ranging between 700-1,000°C for a designated test period without exhibiting Exclusive perforations, structural holes or seam failures. Mechanical stability:

To ensure the product can survive harsh operational handling, it must pass strict cutresistance parameters (complying with EN ISO 13997). Crucially, the blanket’s integrated holding loops must undergo a static load test of 100 kg, followed by a dynamic drop test of an additional 25 kg, without any fraying or detachment.

Chemical integrity: The standard dictates that exposure to a hostile mix of automotive fluids must not degrade the blanket’s protective performance. Ergonomics and safety: The standard requires physical proof that a maximum of two personnel can deploy the blanket over a vehicle within 30 seconds, in all conditions.

It also mandates specific colour-coding to ensure flawless handling in high stress environments.

Fire Cloak™ and certified lithium battery fire containment

The transition toward verified, evidence-led procurement is exemplified by solutions like the Fire CloakTM Lithium Battery Fire Limitation Blanket. Developed and manufactured within the UK, it represents a deliberate shift toward a highly engineered, purpose-built safety tool.

By achieving full testing and certification to the rigorous DIN SPEC 91489:2024-11 standard, the development pathway of Fire CloakTM highlights the precise engineering choices required to survive a modern battery emergency. Every component is optimised to withstand prolonged thermal shock while significantly reducing toxic vapour escape.

Crucially, the certification provides procurement teams, safety engineers and risk insurers with transparent, documented proof of capability. It removes the element of guesswork and provides businesses with operational confidence that their containment equipment will perform exactly as intended.

Building a holistic lithium battery fire safety strategy

A certified fire limitation blanket must be viewed as a critical component within a broader, risk-management strategy. Staff must be comprehensively trained on deployment protocols, proper personal protective equipment and clear dynamic risk assessments to determine exactly when it is safe to intervene.

Furthermore, the standard dictates that the blanket must be stored in a protective container offering at least IP65 ingress protection to prevent dust and moisture degradation over time.

The electrification of global infrastructure brings undeniable benefits, but it demands an equally modern approach to safety. Organisations can no longer rely on old assumptions or unverified equipment. By shifting the operational focus toward certified containment and anchoring procurement in definitive standards, businesses can protect their people, secure their infrastructure and bring true continuity to the electrified age.