Battery storage standard UL 9540A updated with large-scale fire testing

Battery storage standard adds large-scale fire testing

UL Standards & Solutions has published the sixth edition of UL 9540A, adding large-scale fire testing requirements to the standard for evaluating thermal runaway fire propagation in battery energy storage systems.

The new edition was published on 13 March and is described it as a key standard for battery energy storage systems (BESS), including lithium-ion systems.

The standard is titled UL 9540A, Standard for Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems, and is identified by UL as the American and Canadian national standard for assessing fire propagation related to thermal runaway events in energy storage systems (ESS).

UL said testing to the standard is an essential element of due diligence when the design or installation conditions of an ESS exceed the limits set by National Fire Protection Association (NFPA) 855, NFPA 1, the International Fire Code (IFC) or the International Residential Code (IRC).

UL 9540A is the only consensus standard explicitly cited in NFPA 855 for large-scale fire testing and the only national standard in the US and Canada for fire safety testing methods for battery ESS.

UL also said it offers testing aligned with both the fifth and sixth editions of UL 9540A.

Battery storage testing and CSA Group response

CSA Group published comment from Dana Parmenter, Commercial Vice President, Industrial at CSA Group, on what the sixth edition may mean for manufacturers and authorities having jurisdiction.

Parmenter said: “The release of the 6th Edition of UL 9540A in March 2026 establishes a new precedent in the energy storage system (ESS) testing and certification ecosystem.

“This change will raise many questions for manufacturers around enforcement timelines, jurisdictional adoption, and how updated requirements may be interpreted by AHJs.

“This edition expands testing expectations and introduces large scale fire (LSFT) testing requirements within the certification process.

“Section 10 requires LSFT to demonstrate that fire will not propagate between ESS units.

“This change is part of a larger trend across ESS standards, placing greater emphasis on LSFT as it relates to system level safety.”

CSA Group said NFPA 855 Section 9.2.1.2.1 requires large-scale fire testing to characterise gas composition and demonstrate non-propagation between ESS units, which involves gas analysis and calorimetric data such as heat release rate (HRR).

It added that previous editions of UL 9540A did not explicitly incorporate large-scale fire testing, and said the sixth edition now addresses spacing and fire propagation as safety considerations within the certification framework.

CSA Group said CSA/ANSI C800:25 continues to address performance-based characterisation, including heat release rate, target unit measurements such as heat flux, operation of detection systems, battery management system data, and a framework for acquiring data for fire protection engineer analysis.

Complementary roles in ESS approvals

CSA Group said NFPA 855 Section 9.2.2.2 requires interpretation of test results by a registered fire protection engineer, and added that many engineers recommend HRR and other measurements in CSA/ANSI C800:25 to support their analysis.

It said CSA/ANSI C800:25 can be used alongside UL 9540A to provide additional performance and engineering-based data for site-specific installation requirements, engineering approvals and AHJ review.

Parmenter added: “UL 9540A and CSA/ANSI C800:25 now serve more distinct, yet complementary, roles within the ESS testing and approvals process.

“Looking ahead, both standards may be applied to support demonstration of alignment with NFPA 855.

“UL’s recent revisions to UL 9540A expand the scope of safety focused requirements by incorporating certain performance-based considerations, such as those informing spacing and propagation mitigation, into the certification framework.

“CSA/ANSI C800:25 continues to provide additional performance and engineering-based characterization, including data elements that remain optional or out of scope under UL 9540A.”

Fire testing collaboration launched to support UK building safety reforms

Fire testing rules tighten inside the FPA UL PartB plan

The Fire Protection Association (FPA) has announced a collaboration with UL Solutions and PartB to deliver independent fire testing for the UK built environment at a time of strengthened regulation and closer scrutiny of construction products.

The collaboration is outlined in a joint paper titled Testing Times: a solutions-focused collaboration for UK fire testing.

According to the FPA, the aim is to provide impartial and transparent testing services that support compliance in a sector shaped by the Building Safety Act and the findings of the Grenfell Tower Inquiry.

The organisations highlighted that the Building Safety Regulator’s Gateway programme and extended liability under the Defective Premises Act have increased pressure on dutyholders to evidence the fire performance of products and systems.

They stated that stakeholders now need reliable data to show that every component and assembly used in construction meets defined fire safety standards.

Independent laboratory and response to inquiry findings

The FPA said it will use its independent fire testing laboratory to host testing commissioned by UL Solutions and PartB clients in a secure and confidential environment.

The organisation stated that tests will be carried out at arm’s length from the client to protect impartiality and ensure that intellectual property and proprietary data remain confidential.

The initiative is positioned as a direct response to issues raised in the Grenfell Tower Inquiry Phase 2 report around the need for independent testing to rebuild trust in the construction sector.

According to the partners, access to impartial fire performance data is intended to help clients make better-informed choices, reduce remediation costs and show a commitment to recognised good practice.

FPA Chief Executive Dr Gavin Dunn said the collaboration is intended to address gaps in how complex building systems are assessed.

Gavin Dunn, FPA Chief Executive, said: “This new collaboration addresses a critical gap in the construction sector: the need to test and certify the fire performance not just of individual products, but increasingly also the interfaces and combinations of systems that often present the greatest fire safety risks.

“Leveraging the FPA’s independent testing capabilities, UL Solutions’ certification expertise, and PartB’s engineering insight, offers a holistic approach to fire safety validation for the whole UK built environment sector.”

Roles for FPA UL Solutions and PartB

UL Solutions was described as bringing more than 130 years of global experience in testing, inspection and certification to the collaboration.

The firm’s work helps manufacturers meet regulatory requirements and obtain market access through established certification schemes.

Through this collaboration, UL Solutions and the FPA plan to offer testing of building products and systems such as wall assemblies, fire doors and joint systems.

The partners said this work will support both UKCA and CE-marking requirements for applicable products and systems.

PartB was presented as a provider of pragmatic fire safety solutions based on real-world project experience and engineering judgement.

The company’s approach is focused on offering engineered alternatives to conventional remediation, which can avoid invasive and high-cost work while maintaining safety performance.

According to PartB, its experience shows that compliance can in some cases be achieved through engineered solutions that maintain fire safety without defaulting to full-scale replacement.

Jamie Davis, PartB Group Chief Technical Officer, explained that the publication of the white paper marks an important step for the partners.

Jamie Davis, PartB Group Chief Technical Officer, said: “We are proud to announce the publication of this white paper.

“It marks a significant progress in enhancing collaboration to ensure proper testing and compliance measures.

“By sharing these insights, we aim to promote safer building environments and strengthen our commitment to innovation and technical excellence in fire risk mitigation, in a proportionate and responsible manner”

Panel session at London Build and access to the paper

The FPA said representatives from the three organisations will take part in a panel discussion on the Fire Safety Stage at London Build to explain how the collaboration relates to modern methods of construction.

The session, titled Ensuring Fire Safety in MMC: Addressing Industry Concerns, is scheduled for Thursday 20 November at 10:00.

Speakers are due to include Simon Ince, Programme Manager – UK/Europe Codes and Regulatory Services at UL Solutions, George Edwardes, Technical Director at the Fire Protection Association, and Richard Howells, Managing Director (Technical Services) at PartB.

The panel will also feature Jon Cumberlidge, Co-Founder and Director at C3 Design Approvals.

The FPA confirmed that hard copies of the joint paper will be available at the panel session and at the FPA trade stand during London Build.

The organisations added that the full Testing Times paper on the collaboration can also be downloaded online.

They stated that the collaboration is intended to support a safer, greener and higher-quality future for UK buildings by providing reliable, independent fire performance data to project teams.

How independent fire testing data could be used in practice

For architects, fire engineering consultants and building services engineers working on UK projects, this collaboration offers a route to obtain independent fire performance data on products, systems and interfaces that have been tested in an impartial laboratory environment.

For facility managers across industrial, commercial and public sectors, the availability of transparent test evidence may help in assessing existing installations and planning remediation strategies where fire safety concerns have been identified.

For system installers, fire-protection contractors and risk assessors, access to testing that covers complete assemblies such as wall systems, fire doors and joints can support more accurate specification and on-site verification of installed solutions.

For standards and certification bodies and relevant government departments, the partners’ stated focus on impartial testing and traceable data aligns with regulatory frameworks linked to the Building Safety Act, the Building Safety Regulator’s Gateway programme and extended liability under the Defective Premises Act.

For organisations working with modern methods of construction, the London Build panel and the Testing Times paper provide insight into how engineered solutions and system-level testing approaches are being applied to address fire safety concerns in newer forms of construction.

Fire blankets may pose explosion risk during electric vehicle fires, warns NFPA and UL

Research finds fire blankets may trap explosive gases during battery fires

The NFPA and UL Research Institutes have reported that using fire blankets during electric vehicle fires with battery involvement may increase explosion risk.

According to a joint notice from the Fire Protection Research Foundation (FPRF) and the Fire Safety Research Institute (FSRI), fire blankets can eliminate open flames but may trap flammable gases underneath.

The notice warned that gases accumulating beneath the blanket during battery thermal runaway could ignite explosively if oxygen is reintroduced.

Fire blankets linked to confined gas build-up in experiments

The FPRF reported that during controlled testing, fire blankets used to cover burning electric vehicles succeeded in cutting off flames by limiting oxygen flow.

However, battery thermal runaway continued even after the flames were extinguished, releasing flammable gases into the space beneath the blanket.

The Foundation stated that in some trials, this created an explosion hazard for nearby responders when the confined gases mixed with fresh air.

Four suppression methods assessed in current FPRF project

The FPRF is analysing firefighting strategies through its ongoing research project titled Assessment of EV Firefighting Tactics, Tools and the Impact on Stranded Energy.

The Foundation explained that recent testing compared the use of standard hose streams (with and without added agents), fire blankets, and firefighting appliances on electric vehicle fires.

Preliminary findings will be presented at the NFPA Conference & Expo on 16 June 2025 in Las Vegas, and full results will be published later this year at nfpa.org/foundation.

FSRI conducting parallel studies on EV fire suppression

The FSRI is independently studying battery fire hazards and suppression techniques under its Fire Safety of Batteries and Electric Vehicles programme.

According to the Institute, it is evaluating hose streams, under-vehicle water nozzles, and fire blankets as control measures in confirmed battery pack fire incidents.

The FSRI stated that analysis of video footage and performance data is ongoing, with findings to be released later in 2025 at fsri.org.

Focus remains on firefighter safety during EV incidents

The FPRF said that its research aims to support safer incident response procedures for EV fires by identifying effective tactics and understanding the risks of re-ignition and gas build-up.

The FSRI added that its work is directed at enabling better control strategies and reducing hazards for emergency responders.

Both organisations emphasised that no suppression method is without risk, and current findings should inform future training and operational guidance.

NFPA warns of fire blanket hazard in EV fire suppression: Summary

The NFPA reported that fire blankets used during electric vehicle battery fires may pose an explosion risk.

This risk arises from the accumulation of unburned flammable gases beneath the blanket.

The Fire Protection Research Foundation and the Fire Safety Research Institute issued a joint notice on 2 June 2025.

They warned that introducing air into this gas buildup could cause ignition.

The warning is based on ongoing research into EV firefighting tactics and suppression tools.

The FPRF tested four approaches: hose streams with and without additives, fire blankets, and firefighting appliances.

Preliminary results will be presented at the NFPA Conference & Expo in Las Vegas on 16 June 2025.

A full report will follow in autumn 2025 at nfpa.org/foundation.

The FSRI is conducting separate experiments under its own battery safety research project.

Its tests included standard and under-vehicle water application and fire blankets.

The FSRI will publish its findings later in 2025 at fsri.org.

Both organisations aim to improve responder safety and inform tactical decisions.

Stat-X achieves UL-EU certification for EN 15276-1 fire suppression standard

Stat-X product line gains UL-EU certification for EN 15276-1 standard

Fireaway Inc. has reported that its Stat-X fire suppression generator product line has obtained UL-EU certification from UL Solutions, confirming compliance with the EN 15276-1 standard.

According to Fireaway Inc., the certification process assessed the Stat-X system’s performance, safety, and reliability against European standards for condensed aerosol fire suppression systems.

The company explained that the certification supports expanded global market access and provides formal third-party validation of the product’s capabilities.

Lance Harry, P.E., President and CEO of Fireaway, said: “This certification is a testament to our team’s relentless pursuit of quality, safety, and innovation.”

Harry added: “Meeting the EN 15276-1 standard through UL Solutions not only validates our technology – it strengthens our promise to customers worldwide who rely on Stat-X for critical fire suppression needs.”

Karine Johnfroe, Vice President and General Manager of the Built Environment group at UL Solutions, said: “While many fire suppression systems claim efficacy, only those that meet the most demanding third-party testing benchmarks earn this level of recognition.”

Johnfroe added: “UL Solutions is proud to support efforts in delivering trusted fire suppression solutions to the global market.”

EN 15276-1 certification requirements explained

Fireaway Inc. explained that EN 15276-1 governs the design, testing, and performance of condensed aerosol fire suppression systems across Europe.

The company stated that the standard ensures systems are capable of suppressing Class A, Class B, and Class C fires safely, with consideration for human health and environmental impact.

According to Fireaway Inc., the Stat-X system’s compliance with EN 15276-1 demonstrates its ability to meet stringent technical and safety standards required for European markets.

Benefits of certification for Stat-X distributors and customers

Fireaway Inc. reported that the UL-EU certification will expand opportunities for Stat-X distribution and project approvals across Europe.

The company noted that distributors and customers had specifically requested certification to enable access to new projects requiring EN 15276-1 compliance.

Fireaway Inc. added that while the certified Stat-X units retain the same functionality as previous models, the certification provides distributors and customers with additional assurance when pursuing new markets.

Stat-X system features and deployment applications

Fireaway Inc. outlined that Stat-X systems are fixed and portable condensed aerosol fire suppression units designed for a wide range of sectors.

The company explained that Stat-X units have a service life of 15 years and are used in environments including mines, military vehicles, rolling stock, energy storage systems, telecom sites, and marine applications.

Fireaway Inc. added that Stat-X devices are non-toxic, eco-friendly, and capable of being activated thermally, manually, or electrically through standard control panels.

Stat-X achieves UL-EU certification for EN 15276-1 fire suppression standard: Summary

Fireaway Inc. reported that its Stat-X product line has received UL-EU certification for EN 15276-1 from UL Solutions.

The certification process evaluated the Stat-X system against European standards for condensed aerosol fire suppression systems.

Lance Harry, President and CEO of Fireaway, stated that the certification validates the system’s quality, safety, and innovation.

Karine Johnfroe, vice president and general manager at UL Solutions, said that UL Solutions supports the delivery of trusted fire suppression solutions.

Fireaway Inc. explained that EN 15276-1 certifies a system’s ability to suppress Class A, B, and C fires safely.

The company stated that the certification enhances Stat-X’s credibility and market access in Europe.

Fireaway Inc. added that distributors requested this certification to meet project requirements for EN-compliant systems.

The company outlined that Stat-X units have a 15-year service life and are used globally across a wide range of sectors.

Japan updates lithium-ion battery safety standards for enhanced monitoring and fire prevention

Japan adopts new international standards for lithium-ion batteries

In a significant move towards bolstering the safety of lithium-ion batteries, Japan’s Ministry of Economy, Trade, and Industry (METI) announced the replacement of the DENAN Standard J62133-2 (2021) Appendix 9 with Appendix 12 of the International Electrotechnical Commission (IEC) standard 62133-2 (2017).

This transition, utilising detailed guidance and support from UL Solutions Japan, is effective by December 27, 2024 and aims to incorporate more rigorous monitoring methods and safety requirements for portable secondary batteries under the Electrical Appliances and Materials Safety Act.

The new standard focuses on preventing fire accidents by introducing comprehensive testing measures, including constant charging and temperature cycling tests.

Advantages of the new standard for manufacturers and importers

The adoption of Appendix 12 introduces a methodical approach to monitoring each cell or cell block within a battery pack, a procedure not specified in the former Appendix 9.

This development is expected to facilitate easier, faster, and more precise battery monitoring, significantly reducing the complexities and costs associated with achieving Product Safety Electrical Appliance and Material (PSE) certification.

This change is particularly beneficial for manufacturers, importers, and exporters engaged in the Japanese and international markets, ensuring compliance with safety standards.

Preventing fire accidents through enhanced battery testing

Appendix 12 is strategically designed to mitigate the risks associated with the overcharging of lithium-ion batteries, addressing a critical safety concern.

The standard specifies several tests, including battery cells’ constant charging for 28 days, temperature cycles, low pressure simulation, high-rate charging, and overcharge protection.

These measures aim to enhance the safety and reliability of lithium-ion batteries, contributing to the prevention of fire accidents.

The evaluation of compliance with Appendix 12 standards may rely partly on CB IEC Test Reports and Certificates, albeit with a requirement for case-by-case verification to ensure adherence to all necessary items and Japanese national differences.

Seeking further information and compliance guidelines

For manufacturers and stakeholders looking to navigate the transition from Appendix 9 to Appendix 12, METI and UL Solutions Japan offer detailed guidance and support.

Stakeholders are encouraged to consult these resources for comprehensive information on the new requirements and assistance in ensuring compliance with the updated standards.

IFSJ Comment

The transition to IEC standard 62133-2 (2017) Appendix 12 by Japan’s METI, with guidance from UL Solutions Japan, underscores the importance of proactive measures in preventing fire hazards associated with battery technologies.

By introducing rigorous testing procedures and enhancing monitoring capabilities, Japan sets a an example of regulatory adaptation to technological advancements.

UAE adds UL Solutions’ Carugate site to list of recognised testing laboratories

United Arab Emirates (UAE) Ministry of Interior General Directorate of Civil Defense has updated its list of accepted laboratories to include the UL Solutions laboratory in Carugate, Italy.

UL International Italia S.r.l. is now recognised as a testing laboratory that can conduct emergency lighting testing and issue test reports to UAE requirements in accordance with the International Accreditation Service (IAS).

The UL Solutions Carugate laboratory is recognised for testing the following products and standards: Emergency lighting luminaires per EN 60598-2-22; Automatic test lighting systems per EN 62034; and Central battery lighting systems per EN 50171.

To earn the Emirates Quality Mark (EQM), a third party such as UL Solutions must issue an IEC CB certificate for electrical safety within the last three years. Hazardous substances must also have test reports from a third-party laboratory accredited to ISO/IEC 17025.