Thermal Runaway Is Not a Future Risk. It Is Happening Now on UK Commercial Sites and Most Are Not Adequately Protected.
In January 2025, a massive thermal runaway event at the Moss Landing Energy Storage Facility in California forced the evacuation of 1,500 residents. The fire was allowed to burn out due to the risk of explosion underscoring the defining characteristic of thermal runaway at commercial scale: once initiated, it cannot simply be extinguished. Closer to home, UK fire services are attending at least three lithium-ion battery fires every day. The National Fire Chiefs Council has warned that UK safety standards are lagging behind lithium-ion battery risks, and that building regulations guidance must be updated to address fire risks from battery storage and charging.
The scale of lithium battery deployment across UK commercial premises in 2026 is unprecedented. Electric vehicles are charging in fleet depots, office car parks, retail parks, and warehouses overnight. Battery energy storage systems are being installed across commercial and industrial sites to support grid connection and renewable energy integration. E-bikes, e-scooters, power tools, and battery product stock are stored in warehouses at volumes that have grown exponentially in four years.
The fire risk embedded in that deployment is thermal runaway a self-sustaining electrochemical chain reaction that conventional fire safety systems were not designed to address. Thermal runaway in EV batteries is a serious concern with potentially catastrophic consequences. When a single cell overheats due to a fault, it can trigger a chain reaction in adjacent cells, leading to a violent exothermic event and potentially a serious fire incident.
Reducing that risk is not a matter of installing one product or updating one document. It is a multi-layer strategy covering battery management, early detection, physical protection, active suppression, and regulatory compliance all informed by a site-specific assessment that understands what is actually on site, how it is being used, and what the consequences of failure would be.
Fire and Safety UK is a specialist EV and lithium battery fire protection contractor based in Fife, Scotland, operating nationally across the United Kingdom. This guide covers every layer of a credible commercial thermal runaway risk reduction programme.
Part One: Understanding Thermal Runaway What Commercial Decision-Makers Must Know
The Four Stages of Thermal Runaway
Thermal runaway does not begin with a fire. It begins with an electrochemical process that unfolds in stages each of which carries detection and intervention implications for commercial site operators.
Stage 1 Onset. A trigger event overcharging, physical damage, manufacturing defect, or external heat begins to raise internal battery temperature above normal operating range. Cell chemistry begins to destabilise. This stage is detectable through BMS voltage and temperature monitoring, and in some battery chemistries through the earliest traces of off-gas release.
Stage 2 Accelerating decomposition. Internal temperature rises accelerate electrolyte decomposition and separator melting. The battery begins to vent gases carbon monoxide, hydrogen, methane, and ethylene among them. This precursor gas signature is detectable by specialist multi-gas sensor arrays before visible flames or conventional smoke detectors activate. Miniaturised, integrated multi-sensor arrays within battery cells measuring temperature, gas, pressure, strain, and acoustic signals have been identified as an emerging trend in commercial safety monitoring architecture.
Stage 3 Thermal runaway initiation. Internal short-circuit conditions develop fully. The exothermic reaction becomes self-sustaining. Temperatures escalate rapidly reaching 800°C to 1,000°C or beyond and the reaction generates its own oxygen, making conventional suppression agents ineffective. The energy release is violent.
Stage 4 Propagation. The thermal event spreads from the failing cell to adjacent cells. When a single cell overheats, it can trigger a chain reaction in adjacent cells, leading to a violent exothermic event. Propagation can occur within three to ten seconds per module in closely packed commercial battery systems. For commercial sites with high battery density fleet depots, BESS installations, warehouse battery storage propagation from one unit to a multi-unit fire is the defining consequence risk.
Why Conventional Suppression Cannot Manage Thermal Runaway
A conventional fire requires three elements: heat, fuel, and oxygen. Remove any one and the fire cannot sustain itself. This is the principle behind every standard commercial suppression system water removes heat, CO2 displaces oxygen, dry powder interrupts the chemical chain reaction.
Thermal runaway in a lithium-ion battery operates on entirely different principles. The electrochemical reaction generates its own heat, its own fuel from electrolyte decomposition, and its own oxygen from cathode material breakdown. It does not need an external air supply to sustain itself and cannot be interrupted by removing external oxygen. Dry powder suppresses surface flames temporarily it does not cool the cells below the thermal threshold. CO2 removes atmospheric oxygen it has no effect on a reaction that does not depend on it.
Battery management systems must be sophisticated, monitored, and responded to. Gas detection, explosion prevention, fire detection, and fire suppression, as well as a robust emergency response plan, are essential to mitigate the damage if a thermal runaway event does occur. This is not a one-product solution. It is a strategy.
The Reignition Window The Consequence That Outlasts the Fire
A battery fire that appears extinguished has not necessarily resolved the risk. Undamaged cells in a pack that has undergone partial thermal runaway retain stored energy that can re-trigger the electrochemical process hours or days later. This reignition window documented at up to 72 hours in some lithium battery fire scenarios is the post-incident characteristic that makes thermal runaway categorically different from any other commercial fire hazard.
For UK commercial sites, this means that the fire risk management programme must address not only prevention and suppression but the post-incident monitoring period a defined window during which the site must be maintained in a monitored state and the fire and rescue service may need to be recalled. This requirement must feature in every commercial site’s emergency response plan where lithium batteries are present.
Part Two: The Commercial Site Risk Profile Where Thermal Runaway Risk Is Highest
Thermal runaway risk varies significantly by commercial environment. The battery types present, quantities stored, charging behaviour, and physical configuration of the site all determine the specific risk profile and the appropriate risk reduction strategy.
Electric Fleet Depots and Logistics Operations
Fleet depots represent the highest-consequence thermal runaway environment for most UK commercial operators in 2026. The combination of large-format battery packs electric HGVs may carry batteries exceeding 600kWh overnight unattended charging, high vehicle density, and enclosed or semi-enclosed parking creates a concentration of risk that no conventional fire protection programme was designed to address.
In January 2025, the global BESS fire at Moss Landing demonstrated the consequences of thermal runaway in large-format battery environments. For fleet depots, the equivalent scenario is a single vehicle fire propagating to adjacent vehicles in a high-density charging bay configuration a scenario confirmed by fire safety specialists as one where propagation cannot be stopped once thermal runaway is established if vehicle separation distances are inadequate.
Our guide to EV fire safety for logistics and haulage companies covers the specific risk profile and protection strategy for fleet depot environments in detail. Our guide to fire risk assessments for businesses with EV fleets provides the complete assessment framework for fleet operators.
Battery Energy Storage Systems
Battery energy storage is being installed across UK commercial and industrial sites at pace as of early 2025, at least 909 BESS facilities were operational, granted planning permission, or under construction in the UK. BESS installations concentrate the highest stored energy densities of any commercial battery environment. A single thermal runaway event in a large-format BESS can result in a fire that cannot be directly suppressed the January 2025 Moss Landing event was allowed to burn out rather than risk explosion during suppression attempts.
For UK BESS operators, the thermal runaway risk reduction strategy must include sophisticated BMS monitoring, multi-gas precursor detection, advanced fixed suppression, and compliance with IEC 62619, IEC 62933, and the UK Government’s guidance for grid-scale electrical energy storage systems. Our EV fire specialists team has direct advisory capability for BESS environments.
Warehouses and Distribution Centres
Warehouses storing lithium battery products e-bikes, power tools, consumer electronics, EV components, and battery replacement stock face a concentration of thermal runaway risk that is growing year on year as battery product volumes in UK distribution networks increase. A single failing cell in a warehouse battery storage area can propagate through adjacent stock in a fire pattern that standard warehouse sprinkler systems were not designed to contain.
For Welsh warehouse operators, our guide to fire risk management for businesses storing lithium batteries in Wales covers the specific regulatory context and risk reduction framework. For warehouse operators across the UK, the same principles apply with the RRFSO 2005 as the applicable legislative framework.
Enclosed Commercial Car Parks
Enclosed and underground car parks with EV charging provision represent a thermal runaway risk environment where the consequences of an uncontained event extend beyond the car park itself into the building structure above and the evacuation pathways serving both. Research published in December 2025 specifically questions whether standard overhead sprinkler systems are adequate for EV battery fires in enclosed parking environments, recommending formal research into whether the hydrocarbon fire growth curve is more appropriate than the standard time-temperature curve for EV fire scenarios.
For commercial office buildings with enclosed car park EV charging in Scotland, our guide to commercial EV charging fire safety for office buildings in Scotland covers the specific legislative and protection requirements.
Data Centres and High-Value Infrastructure
As data centres implement BESS for power resilience, thermal runaway risk enters a new class of consequence environment. A single failure in a densely packed data centre environment can threaten the entire facility. For data centre operators, the thermal runaway risk reduction strategy must address both the BESS installation and the interaction between a thermal event in the battery environment and the data centre infrastructure it is designed to support.
Part Three: The Thermal Runaway Risk Reduction Framework
Reducing thermal runaway risk on commercial sites requires a layered strategy. No single technology or measure provides complete protection. The following framework covers every layer of an effective commercial thermal runaway risk reduction programme.
Layer 1 Battery Management System Quality and Configuration
The Battery Management System is the first and most immediate line of thermal runaway risk reduction for any commercial battery environment. A properly configured and maintained BMS monitors cell voltage, temperature, current, state of charge, and internal resistance in real time and triggers protective actions when anomalies are detected.
While a BMS can effectively prevent faults such as external overheating, overload, or deep discharge, it cannot completely eliminate the possibility of internal short-circuit faults these may be caused by manufacturing defects and are not always detectable through external monitoring alone. For commercial sites, this means that BMS quality and configuration is a necessary first layer, not a sufficient complete solution.
For fleet operators and BESS managers, the BMS evaluation as part of any thermal runaway risk assessment should cover: whether the system provides cell-level monitoring (not just pack-level); whether it includes active energy dissipation capability in response to internal short-circuit detection; whether it is AI-enhanced with predictive analytics capability for degradation trajectory modelling; and whether it is connected to a cloud monitoring platform providing remote visibility and alert capability.
Our guide to early detection technologies for lithium battery failure prevention explains how AI-enhanced BMS platforms and IoT-connected monitoring are being commercially deployed across UK fleet and BESS environments, and what the current generation of battery diagnostics technology can and cannot deliver.
Layer 2 Specialist Early Warning Detection Systems
Early detection is the highest-impact risk reduction intervention available to commercial sites beyond BMS provision. The critical advantage of specialist detection over suppression is the intervention window it creates potentially minutes before a thermal event escalates to a point where suppression is the only remaining option.
Thermal runaway prediction and early warning approaches are classified into four categories: electrical (BMS-based voltage and impedance monitoring), thermal (temperature sensor arrays including internal RTDs), mechanical and gas (pressure sensors, off-gas detection), and data-driven (machine learning models applied to operating data). Commercial deployment is increasingly combining all four in integrated detection architectures.
For commercial sites, the most immediately deployable early warning upgrade is multi-gas sensor array installation in enclosed battery environments. Gas sensors detect the precursor signature CO, CO2, H2, CH4, ethylene before visible flames or conventional smoke detectors activate. In some commercial deployments, this provides advance warning of up to 30 minutes before the thermal event becomes uncontrollable, giving operators time to isolate the affected battery, initiate evacuation, and deploy suppression before fire brigade arrival.
The practical implications for commercial site managers are direct. For an enclosed fleet depot where vehicles charge overnight unattended, a gas sensor array connected to an automated alarm system that suspends charging and notifies the duty manager transforms the risk profile of that unattended charging period. For a BESS installation, integrated gas and temperature monitoring connected to the automatic suppression system provides the detection-to-suppression link that converts an isolated thermal event into a contained incident rather than a facility-threatening fire.
Layer 3 Passive Fire Protection Measures
Passive fire protection does not respond to a fire it controls what a fire can do when it occurs. For commercial sites with thermal runaway risk, passive measures address the propagation of a thermal event from one battery, module, or vehicle to adjacent assets and building structure.
Active systems such as cooling, sensing, and suppression dominate capital expenditure in commercial battery fire protection, while passive systems including mica, ceramics, aerogels, coatings, and other materials continue to provide essential protection against thermal runaway propagation. These material-level passive measures are embedded in battery pack design by manufacturers but building-level passive protection is the responsibility of the site operator and the fire protection contractor.
Building-level passive fire protection for commercial battery environments includes:
Fire compartmentation. Defining compartment boundaries that contain a thermal event within a defined zone preventing it from accessing escape routes, adjacent occupancies, or critical infrastructure. For BESS installations, IEC 62619 specifies compartmentation requirements between battery modules and between the battery room and adjacent plant.
Fire stopping around cable penetrations. EV charging infrastructure and BESS electrical connections create cable routes through compartment boundaries. Every penetration through a fire-rated element must be sealed with appropriate fire stopping to maintain compartment integrity during a thermal event.
Structural fire protection. The higher heat release rate of a lithium battery fire and the longer burn duration may exceed the fire resistance of structural elements designed to standard fire growth curve assumptions. For enclosed car parks and BESS enclosures, structural fire protection may require upgrade.
Physical separation and fire barriers. For fleet depots where vehicle separation distances cannot be increased to the level that would prevent propagation, physical fire barriers between charging rows provide a passive propagation check that reduces the multi-vehicle scenario risk.
Our guide to what to look for when choosing an EV fire protection contractor explains what capability to look for in a contractor across both passive and active fire protection layers.
Layer 4 Active Suppression Systems for Thermal Runaway Events
Where thermal runaway initiates despite the detection and management measures in place, active suppression systems are the final line of protection against catastrophic consequences. For commercial sites, the three primary active suppression systems for thermal runaway events are:
The Turtle Fire System. The Turtle Fire System is a deployable vehicle-level suppression device that delivers high-volume water cooling directly to the battery pack from beneath a burning vehicle. It addresses the fundamental limitation of overhead suppression it reaches the battery pack from below, where the thermal event originates, rather than from above where water cannot penetrate the vehicle floor. It operates unmanned once deployed, reducing operator exposure to the toxic gas environment, and requires no fixed installation. For fleet depots, logistics operators, and commercial sites where a staffed first response is available within the critical early minutes of an incident, the Turtle system is the primary deployable vehicle-level suppression solution.
EV FirePro Bay-Level Fixed Suppression. EV FirePro is a permanently installed, floor-mounted system that activates automatically when a thermal event is detected in an individual EV parking or charging bay. It delivers upward water spray to the vehicle undercarriage and lateral protection to adjacent bays independently tested at Applus+ Laboratories under simulated EV thermal runaway conditions in an enclosed parking environment. For commercial sites where unattended overnight charging is standard enclosed car parks, fleet depot charging bays, retail park charging areas EV FirePro provides automatic, bay-specific protection that operates without any human presence or intervention.
Trident Synthetic Fire Foam Concentrate. Trident is a PFAS-free synthetic foam concentrate designed for lithium battery fire environments. Where foam application forms part of the site’s fire response, Trident replaces AFFF with a compliant, high-performance alternative that addresses both the suppression requirement and the reignition inhibition need for the extended post-incident window. Its biodegradable formulation also addresses the contaminated firewater runoff obligation that applies to commercial sites subject to Environment Agency or SEPA environmental conditions.
For a complete head-to-head comparison of these systems including their deployment conditions, independent testing credentials, and appropriate commercial application our guide to comparing EV fire protection solutions for commercial sites provides the full product landscape analysis.
Layer 5 Specialist Fire Risk Assessment
Every layer of a thermal runaway risk reduction programme must be informed by a site-specific fire risk assessment that evaluates the specific batteries present, the operating conditions, the building configuration, and the existing protection provision. Generic assessments applied without EV or lithium battery specific content are not legally adequate for commercial sites with significant battery risk.
The Regulatory Reform (Fire Safety) Order 2005 has been updated to stipulate that fire risk assessments must now explicitly consider lithium-ion battery risks. A commercial site operating in England or Wales without a current, specialist fire risk assessment covering its thermal runaway hazards is in breach of its statutory obligations. For Scottish sites, the equivalent duty applies under Section 53 of the Fire (Scotland) Act 2005.
A specialist fire risk assessment for a commercial site with thermal runaway risk must cover: battery type and quantity profiling; charging infrastructure configuration and electrical infrastructure adequacy; detection system adequacy for off-gas precursor identification; suppression system performance against thermal runaway events; passive compartmentation status; vehicle separation distances and propagation pathways; reignition protocol; and compliance against PAS 1899, the applicable fire safety legislation, and insurer requirements.
Part Four: Thermal Runaway Risk Reduction by Commercial Site Type
The following table summarises the primary thermal runaway risk factors and risk reduction priorities for each major commercial site type.
| Commercial Site Type | Primary Thermal Runaway Risk | Priority Risk Reduction Measures |
| Electric fleet depot | Large-format battery overnight charging, vehicle-to-vehicle propagation, unattended risk period | Multi-gas detection, Turtle Fire System, EV FirePro for charging bays, vehicle separation assessment, reignition protocol |
| Battery energy storage (BESS) | Large-scale thermal cascade, toxic gas volume, suppression complexity | Advanced BMS with AI analytics, multi-sensor detection array, fixed suppression, IEC 62619 compliance, DESNZ guidance adherence |
| Enclosed commercial car park | Confined gas accumulation, overhead suppression inadequacy, building propagation | EV FirePro bay-level suppression, gas detection, passive compartmentation, emergency procedure update |
| Warehouse with battery stock | Stock density propagation, e-bike and PLEV charging, returns handling | Designated charging zones, off-gas detection, fixed suppression in charging areas, stock separation |
| Manufacturing and industrial | Battery-powered plant and equipment, proximity to combustibles, charging in production areas | Charging zone separation, BMS monitoring, Turtle system for deployable vehicle-level response |
| Retail park with EV charging | Public occupant profile, unattended charging, building proximity | EV FirePro for covered bays, updated evacuation procedures, fire service liaison |
| Data centre with BESS | High-value infrastructure proximity, power resilience dependency, complex evacuation | Integrated BMS and detection, fixed suppression, compartmentation from IT infrastructure |
| Scottish commercial premises | Fire (Scotland) Act 2005 duty holder obligation, Scottish regulatory framework | Scottish specialist assessment, SFRS engagement, Building (Scotland) Regulations compliance |
Part Five: Regulatory Compliance and Insurance Implications
The UK Regulatory Framework for Thermal Runaway Risk Management
Commercial sites managing thermal runaway risk operate within a regulatory framework that is tightening in direct response to the growth of lithium battery deployment across the UK economy.
The Regulatory Reform (Fire Safety) Order 2005 (England and Wales) and Fire (Scotland) Act 2005 both require the Responsible Person or Duty Holder to maintain a suitable and sufficient fire risk assessment. The RRFSO has been explicitly updated to require lithium-ion battery risk to be addressed within that assessment.
PAS 1899, published by the British Standards Institution, establishes baseline fire safety requirements for commercial EV charging infrastructure and is increasingly referenced by enforcing authorities and insurers as the minimum standard for EV charging environments.
Approved Document B, updated with 2025 and 2026 amendments, governs fire safety in construction and refurbishment. For commercial developments incorporating battery energy storage or EV charging, the applicable requirements must be addressed in the design specification.
IEC 62619 and IEC 62933 set minimum requirements for cell monitoring and thermal event response in battery energy storage systems. For BESS operators, compliance with these international standards is the technical foundation of a defensible thermal runaway risk management programme.
The UK Government’s guidance for grid-scale electrical energy storage systems, published by DESNZ, specifically recommends comprehensive monitoring systems for early warning of developing issues alongside fire suppression infrastructure directly supporting the layered detection and suppression strategy described in this guide.
ISO 3941:2026 has introduced Class L as a dedicated fire classification for lithium-ion fires a development that will progressively influence detection and suppression system specification standards across commercial battery environments in the UK.
A new Lithium-Ion Battery Safety Bill is progressing through UK Parliament, introducing mandatory product safety rules and expanded government powers to enforce safety requirements for lithium battery commercial environments. Commercial sites that have not yet acted on thermal runaway risk management will find the regulatory environment increasingly difficult to navigate from a reactive position.
Insurance Requirements for Thermal Runaway Risk Management
Commercial insurers are adjusting their risk models for premises with significant lithium battery exposure at a pace that is outrunning most commercial site operators’ awareness. Battery management systems must be sophisticated, monitored, and responded to and insurers are now asking for evidence of exactly this as part of commercial property underwriting.
For commercial sites seeking to demonstrate adequate thermal runaway risk management to their insurers, the evidence package should include: a current specialist fire risk assessment addressing lithium battery and thermal runaway hazards specifically; documentation of BMS specification and monitoring capability; installation records for early warning detection systems; suppression system installation and commissioning certificates; updated emergency response procedures incorporating reignition protocol; and a scheduled maintenance and inspection programme for all installed systems.
Choosing a BAFE-certified contractor and maintaining full documentation of all assessments, installations, and maintenance provides the audit trail that insurers and enforcing authorities need. For guidance on what contractor selection criteria to apply, our guide to what to look for when choosing an EV fire protection contractor covers the accreditation and competence standards that apply in full.
Part Six: How Fire and Safety UK Delivers Thermal Runaway Risk Management
Fire and Safety UK provides a complete thermal runaway risk management service for commercial sites across the United Kingdom from initial site-specific fire risk assessment through to suppression system specification and installation, ongoing maintenance, and regulatory compliance support.
The company’s specialist capability covers every layer of the thermal runaway risk reduction framework:
A site-specific fire risk assessment addressing thermal runaway hazards at the level of technical depth required by the updated RRFSO 2005, the Fire (Scotland) Act 2005, and the evolving insurer landscape for commercial battery environments.
Specification and installation of the three primary commercial thermal runaway suppression systems the Turtle Fire System for deployable vehicle-level response, EV FirePro for automatic bay-level fixed suppression, and Trident synthetic foam for PFAS-compliant post-incident management.
Early detection system assessment and specification, covering multi-gas sensor arrays, BMS monitoring review, and integration with existing building fire detection and alarm infrastructure.
Passive fire protection assessment and remediation, covering compartmentation, fire stopping around cable penetrations, and structural fire resistance review for the thermal runaway heat profile.
Emergency response plan update incorporating reignition protocol, toxic gas evacuation procedures, fire service liaison requirements, and firefighter information provision.
A structured ongoing maintenance programme ensuring all installed systems remain operational and that the site’s compliance position is maintained as battery technology, fleet composition, and regulatory requirements evolve.
Fire and Safety UK operates nationally from its base in Fife, Scotland covering fleet depots, BESS installations, warehouses, commercial car parks, retail parks, manufacturing sites, and office developments across England, Scotland, Wales, and Northern Ireland. For Scottish commercial sites, all assessments are delivered under the Fire (Scotland) Act 2005 framework. Our dedicated guide to EV fire safety consultancy for businesses in Scotland covers the Scottish regulatory context in full.
For businesses at the early stage of understanding their thermal runaway risk exposure, our guide to how to select an EV fire safety consultant for commercial projects provides the selection framework for identifying a specialist with genuine technical competence in lithium battery fire environments.
Frequently Asked Questions
What is thermal runaway and why is it dangerous for commercial sites?
Thermal runaway is a self-sustaining exothermic chain reaction within a lithium-ion battery cell that generates its own heat and oxygen, reaching temperatures exceeding 1,000°C and releasing toxic and flammable gases. Conventional suppression agents cannot interrupt the electrochemical process. The reignition risk can persist for 72 hours after apparent suppression. For commercial sites with high battery density, propagation from one unit to a multi-unit fire can occur within seconds.
What are the main causes of thermal runaway in commercial battery environments?
Overcharging, over-discharging, external heat exposure, physical damage, manufacturing defects, and battery aging. In commercial settings, overcharging due to faulty charging equipment or BMS failure and physical damage from vehicle underside impacts are the two most operationally common triggers.
How can a Battery Management System reduce thermal runaway risk?
A BMS monitors cell voltage, temperature, current, state of charge, and impedance in real time, triggering protective actions when anomalies are detected. Modern AI-enhanced BMS platforms add predictive analytics that identify degradation trajectories before threshold conditions are reached. Active energy dissipation strategies within BMS have demonstrated significant reduction in thermal propagation consequences.
What detection technologies are most effective for thermal runaway early warning?
Multi-gas sensor arrays detecting CO, CO2, H2, CH4, and ethylene precursor signatures before flames are visible, providing advance warning potentially minutes before escalation. Integrated multi-sensor arrays combining temperature, gas, pressure, strain, and acoustic sensing offer the most comprehensive early warning architecture for commercial battery environments.
What suppression systems are recommended for managing thermal runaway in commercial settings?
The Turtle Fire System for deployable vehicle-level water cooling, EV FirePro for automatic bay-level fixed suppression, and Trident synthetic foam for PFAS-compliant post-incident management. Active systems dominate best-practice specification, while passive mica, ceramic, and aerogel materials provide essential propagation protection.
Is a fire risk assessment legally required for commercial sites with lithium battery risk?
Yes. The RRFSO 2005 has been explicitly updated to require lithium-ion battery risks to be addressed in fire risk assessments for commercial premises in England and Wales. The equivalent duty applies under the Fire (Scotland) Act 2005 in Scotland. A commercial site operating without a specialist assessment is in breach of its statutory obligation.
Which commercial sites face the highest thermal runaway risk in the UK?
Electric fleet depots with overnight charging, large-scale BESS installations, warehouses with high battery stock volumes, enclosed commercial car parks with EV charging, manufacturing sites with battery-powered plant, and data centres using BESS for power resilience.
Thermal Runaway Risk Is Reducible But Only With a Strategy That Matches the Hazard
The gap between what thermal runaway demands and what conventional fire safety systems deliver is not a matter of degree. It is a categorical difference in fire behaviour, suppression requirements, detection capability, and post-incident management obligations.
For UK commercial sites in 2026, the question is not whether thermal runaway risk is present. In any premises with EV charging, battery-powered equipment, or battery energy storage, it is present. The question is whether the risk reduction strategy in place BMS quality, detection provision, passive compartmentation, active suppression, emergency procedures, and documentation is adequate for the specific battery environment on site.
A strategy built on a conventional fire risk assessment, overhead sprinklers, and standard evacuation procedures is not adequate. A strategy built on specialist assessment, multi-gas detection, EV-specific suppression, and a reignition protocol is.
Fire and Safety UK delivers that strategy to commercial businesses across the United Kingdom. Contact us today to arrange your specialist thermal runaway risk assessment.
Email: support@fasukfiregroup.co.uk Phone: 01383 601007 Address: Fife, Scotland, KY8 6AL Operating Hours: Monday to Friday, 9:30am to 5:00pm National Coverage: England, Scotland, Wales, and Northern Ireland