Deakin University’s Hycel Technology Hub is a bespoke hydrogen fuel cell research, testing, validation and training facility with integrated high-flow hydrogen designed to operate at up to 4,000 NLPM and with a supply pressure of 9 bar. The facility was designed with reference to full HAZOP study and is an exemplar of best-practice hydrogen safety standards. Building design, specialised ventilation systems gas and flame detection systems, and finishing materials work in concert to ensure a safe and Australian-leading hydrogen facility. Safety audits, conducted by Swagelok and Draeger, exemplify Hycel’s commitment to best practice safety approaches. Commissioned in October 2024 and currently undertaking industry-based fuel cell testing and validation, Hycel Technology Hub is gathering and sharing lessons learned. This presentation will discuss Hycel Technology Hub’s design, construction and commissioning process including pain points and recommendations for improvement.

Hydrogen has been commonly used for years and has a range of properties that are now well understood by the broader industry. Some of those properties, such as flammability and reactivity, mean that hydrogen displays some unique characteristics with respect to explosions. Whilst hydrogen is now familiar to many, some of its properties and how they relate to explosion outcomes, are less commonly understood. This submission will examine the general topic of flammable gas explosion mechanics at a high level. The discussion will cover topics such as: the factors that contribute to explosions, and what elements increase the severity of explosions, with particular focus on confinement, congestion and turbulence. Following the discussion on general explosion mechanics, the submission will relate these specifically to hydrogen and the properties of hydrogen that can lead to increased explosion severity. Finally, the submission will briefly discuss results that have been observed for simulations of the unique case of hydrogen/oxygen explosions within vessels. These CFD simulations have been run for a number of projects to simulate the formation of a flammable atmosphere in an oxygen vessel, typically due to a leaking electrolyser stack membrane allowing a hydrogen to leak into an oxygen/water separator. Whilst the results are based on simulation only, they have provided insight into the potential consequences of these events and the means to practicably mitigate them.

Industry has extensive experience in using hydrogen, however, many new applications require hydrogen to be deployed close to the public. One mitigation measure that is frequently encountered in hydrogen installations is the use of fire walls to protect equipment, buildings, roads and other public places from potential jet fires. However, the use of fire walls can also increase the accumulation of hydrogen due to the reduction in ventilation caused by the walls. The accumulation of a large flammable cloud of hydrogen can result in large explosion overpressures in case of ignition. In particular, hydrogen clouds at concentrations above 10% can undergo a deflagration to detonation transition (DDT), which would result in severe overpressures and potentially catastrophic damage. This contribution will present a study of several accidental release scenarios in a typical hydrogen storage facility. CFD modelling was used to understand the effect of the presence and geometry of fire walls and storage tank configurations on the air flow patterns to check whether there are areas of low ventilation where hydrogen could accumulate. The dispersion behaviour of different leaks was then simulated, allowing us to understand how the fire walls and tank geometry influence both the size and concentration of the flammable clouds. Finally, selected flammable clouds were ignited to obtain the potential explosion overpressures. The objective of this presentation is to highlight the potential disadvantages to using fire walls as a mitigation measure against thermal criteria and the factors that influence the severity of potential explosions in hydrogen storage facilities.

It is widely reported that hydrogen flames can be difficult to see, thus presenting a hazard whereby individuals could inadvertently come in contact with a naked flame. Whether because of a hydrogen fire, or as part of normal appliance operation, the different flame appearance of hydrogen compared with natural gas will be important for consumer acceptance and could present a safety barrier in the application of residential appliances in a domestic setting. Albeit inconsistently reported, many reference sources state a definitive colour; however, hydrogen flames can be almost any colour of the rainbow. Understanding the flame colour is important, but more critical to ensure safety is whether the flame is clearly visible, and under which conditions it is not reliably detectable by eye. The objective of this work was to isolate and quantify the factors that may influence hydrogen flame visibility, and to determine if flame visibility can be relied upon as an indicator of flame presence in a similar way that natural gas flames are expected to be visible in a domestic setting. A series of experimental testing was performed to assess visibility under real-world conditions. The outcomes highlight that making a safety assessment using conventional descriptions of flame appearance is not recommended because of uncontrolled factors in practical settings.

Safety in Design (SiD) practices are continually evolving across the processing industry. SiD can include comprehensive risk assessments such as HAZID, HAZOP, QRA, LOPA, Bowtie Risk Assessment, Layout Reviews, and SFAIRP studies. The application of SiD depends on industry maturity, regulatory requirements, incident learnings, and the expertise of study leaders. Hydrogen projects are commissioned by operators with varying experience and design standards. A balanced approach is essential to ensure risk is reduced SFAIRP without incurring unnecessary costs. This paper outlines challenges and recommendations for achieving fit-for-purpose SiD in hydrogen projects. Challenges in SiD for hydrogen projects include:

• Vendor ‘Black Box’ Designs: Proprietary vendor equipment (e.g., electrolyser, compressor, storage packages) has confidentiality requirements and risk studies are not always shared with BOP designers, potentially resulting in inadequate safeguards.
• Overseas Equipment Suppliers: Equipment may be designed to standards acceptable in overseas operating environments but may not meet Australian Standards or tolerable risk targets. Initial contractual commitments can prevent necessary modifications during SiD studies due to cost and schedule impacts.
• Understanding Consequences: Outsourced consequence modelling may not be communicated effectively to designers. Early involvement of designers in these studies is crucial for informed layout decisions.
• Developing Australian Standards: Ongoing development of standards for hydrogen facilities can result in inconsistent approaches and designs between practitioners. This paper shares GPA’s experiences across multiple hydrogen design projects, lessons learned, and best practices for integrating SiD. It emphasizes the importance of bridging gaps between safety in design, design, consequence modelling, and vendor package integration.

The storage and transport of hydrogen via tube trailer is a mature technology with a long history of use. High pressure hydrogen is typically stored as compressed gas in a tube trailer to serve many important process applications in the semiconductor industries. The tube trailer is typically filled at hydrogen generation plants, hooked up to a prime mover, and transported to the end user facility. In densely populated areas that have sensitive receptors near roads, it is necessary to assess the risk of loss of containment of the tube trailers during road transportation. In Singapore, safety of road transportation of hazardous materials is managed by the local regulatory authorities through the Quantitative Risk Assessment (QRA) framework. Transporters/logistic companies that transport pressurized hydrogen may be required to undertake a study depending on the packaging container size and transport route, as part of the transport licensing requirements. AcuTech was recently engaged by an industrial gas company to conduct a transport QRA (tQRA) study for the road transport of gaseous hydrogen in tube trailer from their manufacturing facility to the Eastern side of Singapore. This case study presents the challenges and lessons learnt from the tQRA study. AcuTech will discuss credible loss of containment scenarios from hydrogen tube trailer and the resulting event outcomes, risk acceptance criteria for road transportation, limitations on the consequence outcome results generated by software in analyzing impacts to sensitive receptors, and practicable control measures that can be implemented to manage the risk to ALARP for all stakeholders involved.

This research aims to enhance the safety of the steam methane reforming (SMR) process by analyzing potential hydrogen leakage scenarios and optimizing the ventilation system. Given hydrogen's low explosive limit (LEL), any leakage poses a significant risk of accidents. Therefore, the ventilation system has been designed to maintain hydrogen levels below 1% by volume as a precaution. We employ Computational Fluid Dynamics (CFD) simulations to analyze the dispersion of hydrogen concentrations within the actual SMR process layout. The simulations apply the Realizable k-ε turbulence model. We considered a scenario where leaked hydrogen diffuses within the facility and then disperses outdoors through the ventilation system. The study found that placing outlets at the top of the system provided the best ventilation performance, as hydrogen naturally diffuses upward. Ventilation efficiency improved by over 40% compared to the least effective configuration when both the outlet and air intake were positioned on the same wall and at the top. This improvement was attributed to enhanced overall airflow circulation within the facility. These findings offer practical guidelines for designing ventilation systems in SMR facilities to enhance safety.

Whenever hydrogen is present within a system, there is a potential for a hydrogen release. If a release occurs without immediate ignition, a flammable cloud will often develop. These releases present a major safety hazard, as the delayed ignition of a premixed hydrogen-air cloud has the potential to generate significant overpressures. These events are challenging to mitigate, as there are different types of delayed ignition hazards, depending on the nature of the release and its surroundings, each of which can require different mitigation strategies. This presentation outlines the types of delayed ignition hazards a hydrogen release presents, the key parameters that affect their severity, and the most effective strategies to mitigate these events. In addition, current known limitations and gaps in existing codes and standards will be discussed.

In Australia, energy operators are in various project stages in the development of facilities generating, storing and dispensing hydrogen. From a process safety viewpoint, careful consideration of the hydrogen process and storage conditions is required. The same level of risk assessment rigour that is applied to a traditional energy production facility equally applies to new energy facilities. In particular, there are several process safety challenges that apply to a Hydrogen Refuelling Station (HRS). Of note, the management of interfaces between the Person Conducting a Business or Undertaking (PCBU), i.e. the owner/operator of the HRS and vendors designing manufacturing and supplying the packages requires particular attention. Our experience has shown that the HRS process design is relatively complex with various vendor package interfaces that individually have undergone their own risk review process but not in totality. Likewise, the level of process safety assessments varies between the PCBU and the vendor necessitating harmonization to ensure the risks meet operator as well as regulatory risk regimes.

• This paper outlines the challenges that may occur in a project to develop a HRS, including:
• Legislative (health and safety) requirements on the PCBU and equipment designer/manufacturer.
• State stakeholders, requirements and guidance.
• Changes in HRS technology and development of standards over the life of the project.
•  Clarity on key design deliverables and management of documentation.
• Identification of Work Health and Safety (WHS) hazards and issues relating to conduct of Hazard and Operability (HAZOP) studies on vendor packages.
• Assessment of risks and potential conflicts with vendor risk assessments, including Safety Integrity Level (SIL) allocation and verification.
• Tips are provided to address these challenges in delivering a HRS in Australia.

As hydrogen production technologies expand into coastal and offshore settings, particularly through seawater electrolysis that also facilitates ocean-based carbon dioxide removal, new environmental and safety risks must be considered in parallel. This presentation draws on the Equatic project in Canada, which combines hydrogen generation with ocean alkalinity enhancement, to explore the intersecting safety, regulatory, and environmental planning challenges of these emerging systems.

Topics will include:

• Environmental risk considerations associated with hydrogen production in marine contexts, including chlorine by-products, localised pH changes, and hydrogen venting.
• The role of environmental impact assessment and permitting processes in supporting hydrogen safety from the outset.
• Navigating public perception, Indigenous consultation, and multi-agency approvals in sensitive coastal environments.
• Insights on designing safe, scalable, and publicly acceptable hydrogen infrastructure alongside carbon removal goals.
• The presentation offers a planning and regulatory perspective to complement technical safety approaches, helping ensure hydrogen deployment aligns with environmental thresholds, community values, and long-term climate goals.

Standards Australia plays a pivotal role in the development and implementation of standards that drive innovation, safety, and efficiency across various sectors. This presentation will explore the multifaceted benefits of standards and the rigorous process of standards development, highlighting how these efforts contribute to Australia's economic and technological advancement.

With the hydrogen industry feeling some headwinds in recent times, HySafe continues to play an essential role in the delivery of research and technical knowledge that underpins the safe, efficient, and effective regulations, codes, standards, and technologies that will deliver hydrogen based economies. This presentation will consider some of the key areas of focus for research, industry ambition and a summary of some of the cutting-edge research being done by HySafe members around the world.

All of the key decisions about hydrogen that affect its safety are made by hydrogen engineers or managers advised by hydrogen engineers. It is therefore essential that the nascent hydrogen industry is able to determine if is engineers are competent to make those decisions. The question arises as to what competency is and how do we determine if it has been achieved. One very clear way to know this is through having a competency framework for hydrogen engineers. Engineers Australia has embarked on the process of developing a competency framework for hydrogen engineers. The core of the competency framework is competency standards that define competency for each of the tasks/responsibilities hydrogen engineers will have. This competency framework will be useful for a range of activities that support the industry’s hydrogen engineering capability and so have wide application in supporting safety of hydrogen plant and facilities. The paper will set out Engineers Australia’s hydrogen engineering competency framework and how it contributes to safety in the industry.

Gas detection systems are critical safety services for managing risks associated with hazardous gases in industrial environments, particularly where hydrogen and other flammable substances are present. Hydrogen introduces specific challenges due to its high diffusivity, low ignition energy, and broad flammability range. This presentation outlines a risk-based methodology for the implementation and management of gas detection systems as independent protection layers within the broader functional safety lifecycle. It emphasizes the need for robust system design, functional safety integration, and proactive maintenance, supported by a structured management of change process. Key considerations will include detector placement, degradation mechanisms, and proof testing requirements. The presentation reinforces that gas detection systems must be treated as active, performance-based safety functions and maintained to ensure continued risk reduction throughout their operational lifecycle.

Amarna Energy is a specialist consultancy, successfully delivering and supporting renewable hydrogen projects across Australia. This presentation examines the complexities of managing hydrogen-specific equipment suppliers, ensuring compliance with stringent safety, documentation, and operational requirements to facilitate a seamless transition into training, maintenance, and operations. We address the unique challenges suppliers face in meeting the expectations of early adopters, particularly within the Australian regulatory and market context. This presentation provides strategic insights and best practices for effective project integration, including:

• Aligning expectations on technology readiness levels
• Adapting risk management systems to regulatory requirements
• Defining best practices for design and implementation
• Upskilling the existing workforce

By applying these strategies, we aim to enhance the safe and efficient integration of hydrogen technologies, reducing overall project costs for end clients while supporting a sustainable energy transition.

Hydrogen purification through adsorption-desorption cycles, particularly Pressure Swing Adsorption (PSA), is essential in gas cracker units to achieve high-purity hydrogen. However, this process presents safety challenges related to high-pressure gas handling, cyclic pressurization, and impurity management. A comprehensive safety approach is necessary to mitigate these risks effectively. Key safety concerns include pressure fluctuations causing mechanical stress, overheating of adsorption beds, hydrogen embrittlement, and uncontrolled desorption reactions leading to localized temperature spikes. Additionally, the accumulation of flammable gases in vent lines, valve failures, and material degradation pose operational hazards. To enhance process safety, industries must implement: Pressure relief and venting systems to prevent overpressure failures. Gas detection and real-time monitoring to identify leaks and anomalies. Explosion prevention measures, including proper inerting, purging, and controlled venting. Material selection and integrity assessments to mitigate hydrogen embrittlement. Emergency shutdown systems (ESD) and safety interlocks for failure prevention. Compliance with Process Safety Management (PSM) principles, HAZOP studies, and hydrogen safety standards is crucial for risk reduction. This presentation outlines best practices to improve system reliability, emergency preparedness, and incident prevention in PSA operations. By integrating these safety strategies, hydrogen purification facilities can ensure safe and sustainable operations, minimizing hazards while supporting the transition to a hydrogen-based economy.

In the challenging market of sustainable hydrogen production, particularly in the context of innovation, the main problem lies not just in the development of new technologies but in the long-term commercialization of safe and reliable products. Knowing this fact, the use of natural safety algorithms is unavoidable for ensuring lasting safety in products. The design of atmospheric vertical electrolysers exemplifies a commitment to safety and reliability, integrating innovative features that significantly enhance operational safety while utilizing natural safety algorithms. Key design aspects include the use of moderate current density and two-sided cooling, which work together to optimize efficiency while minimizing thermal risks. Operating at atmospheric pressure not only reduces the likelihood of leaks but also ensures a stable environment for hydrogen generation. This presentation will delve into these critical safety features and explore additional considerations that contribute to the overall reliability of atmospheric vertical electrolysers. By sharing insights into the technology’s capabilities, this presentation aims to foster a deeper understanding of best practices in hydrogen production and the challenges of bringing safe products to market in the long term.

This paper presents the critical process safety measures implemented during the commissioning of a 60 Nm³/h green hydrogen generation and blending facility in India. The project integrates alkaline electrolysis for hydrogen production with existing natural gas infrastructure, aiming to significantly reduce CO₂ emissions while ensuring safe and reliable operations. Key safety strategies included precise control of caustic lye pH and concentration within the electrolyzers to prevent corrosion and ensure stable hydrogen output. To maintain product purity, a carefully selected catalyst bed was used for effective moisture removal from hydrogen and oxygen streams. Advanced flow control valves and real-time gas composition analyzers ensured safe blending of hydrogen with natural gas, mitigating flammability risks. The project also addressed construction and commissioning safety challenges, implementing proactive risk assessments and mitigation strategies. Since solar power is not available at night, the facility was designed to manage nighttime operations using stored hydrogen while maintaining pressure stability. To enhance overall safety, multiple protective layers were incorporated, including non-return valves to prevent backflow, pressure relief systems to handle excess gas, and comprehensive emergency shutdown protocols for rapid response to abnormal conditions. This case study highlights the successful integration of green hydrogen into existing industrial operations while prioritizing process safety management. The lessons learned can serve as a model for future hydrogen projects aiming for safe, sustainable, and efficient deployment in industrial applications.

Ark Energy’s SunHQ Hydrogen Hub in North Queensland is a pioneering project contributing to Australia’s energy transition using green hydrogen. Safety and regulatory compliance are critical to the project’s success. This presentation explores how national and international hydrogen standards and regulations were interpreted, adapted, and applied to the project—from plant design and construction through to commissioning and operation. The presentation will discuss the practicalities of aligning the project with Australian Standards, including adopted international standards, in relation to both hydrogen and electrical requirements, the role of robust risk assessments, engineering controls, and active stakeholder collaboration. Key learnings are shared, including consideration of regulatory requirements in design, the complexities of adopting emerging hydrogen technologies, and the importance of engagement with safety regulators. The session also reflects on engagement strategies with local government, highlighting effective approaches that fostered transparency and supported approvals. Successes in collaboration are discussed alongside ongoing challenges. Finally, considerations for future regulatory frameworks that support innovation while maintaining public and environmental safety are discussed. This case study offers valuable insights for organisations navigating the complexities of hydrogen project deployment at small scale in a global market.

While uncertainty remains around hydrogen’s ultimate role in the energy transition, it is clear that hydrogen will play a critical role in specific, well-suited applications. To ensure a safe and reliable industry, it is essential that standards development and adoption continue at pace, providing the necessary frameworks for its effective deployment. This presentation will outline the Hydrogen Technologies Committee’s refreshed work plan and strategic focus, emphasizing the importance of industry-wide collaboration in shaping a robust hydrogen ecosystem. Attendees will gain insight into the current status of Australian hydrogen standards projects, exploring key developments and challenges that influence domestic progress. Additionally, the session will highlight international efforts, particularly within the ISO/IEC space, that are shaping the global hydrogen landscape. Understanding these advancements will be crucial for aligning Australia’s standards with international best practices, driving consistency, and ensuring seamless integration into global markets. By fostering innovation and prioritizing safety, we aim to build a hydrogen industry that is both resilient and adaptable, ready to meet future energy demands. Join us as we explore the evolving standardization landscape and the vital steps needed to secure hydrogen’s place in the clean energy transition.

Many industry standards and guidance documents reference the use of ventilation to mitigate the formation of combustible mixtures of hydrogen within buildings and enclosures. However, current guidance varies and may not protect equipment and personnel in all release scenarios. This presentation provides an overview of the relationship between hydrogen release scenarios and the ventilation rates recommended by key hydrogen consensus standards/guidance to mitigate hydrogen releases inside buildings and process enclosures. By comparing best practice considerations to currently available leak and ventilation guidance, this presentation provides a basis for the Hydrogen Safety Panel to recommend changes to existing standards, highlights the importance of continued research, and potentially forms a basis for development of new standards and guidance.

For all benefits of getting lower carbon emissions, automotive industries are heading towards use of hydrogen powered vehicles. However, a consequence of hazardous gas on heavy truck adds complexity in specification and maintenance. Defining and implementing systematic, safe and adequate methods to handle, maintain the hydrogen powered vehicles is most emerging focus area in Automotive Industry nowadays. The paper studies the relevant regulatory guidelines and requirements for handling of hydrogen powered vehicles. Also, this paper describes methodology adopted for designing a service center and systematic process of handling and servicing complex hydrogen powered vehicles for service industry. Key processes like, Pressurized Hydrogen extraction and re-filling, inert gas filling for creating non-air zones are discussed. Moreover, it describes inception-to-return method post major maintenance including precautions to be taken and control measures. The paper also discusses the skills requirements for service technicians and provides a comparison with reference to Diesel and H2 powered vehicles. It also compares vehicle servicing precautions in the open area vs closed area. It summaries with required steps and associated processes defined for hydrogen powered vehicle servicing.

As hydrogen demand increases, more hydrogen transport vehicles are being built and operated to supply fuel to the growing number of end use applications. Concurrently, recent incidents involving Multiple Element Gas Container (MEGC) hydrogen trailers have highlighted common contributing factors that have resulted in fire and/or explosions. This presentation summarizes common contributors to MEGC incidents including relief device activation and hydrogen accumulation. Potential root causes are used to inform recommendations and technical guidance for the design and operation of trailers transporting hydrogen. Although contributing factors and best practice recommendations are not specific to transportation applications, the risk of collision, high vibration, frequent filling cycles, and high occurrence of recent incidents add emphasis to the focus of this presentation.

Hydrogen has been identified as a key gas in helping Australia meet its obligations as a signatory under the Paris Agreement. There is significant potential for hydrogen to de-carbonise existing natural gas networks through the blending of hydrogen with natural gas and the replacement of natural gas completely with hydrogen. In particular, the potential exists for the use of hydrogen in hard to abate industries where high temperature processes are involved. The challenge that remains is the conveyance of hydrogen through transmission and distribution pipelines to these industries and the conversion of existing gas fired appliances and design of new gas fired appliances while ensuring safety. This presentation will focus on the impact of both hydrogen blended natural gas and hydrogen on transmission and distribution pipelines and supporting equipment as well as the impact of hydrogen on gas fired appliances. Consideration will also be given to necessary changes to infrastructure to ensure safe conveyance and utilisation of hydrogen. Furthermore, the implications of hydrogen gas quality on the operation of hydrogen fuel cells will be considered. An update will also be provided on the revision of the natural gas quality standard AS4564 and how this standard relates to hydrogen blended natural gas.

The design of hydrogen pipelines presents unique safety challenges that require a re-evaluation of traditional risk assessment approaches. While extensive data and well-established methodologies support the evaluation of natural gas pipelines, hydrogen introduces new uncertainties due to its distinct physical properties, alternative ignition behaviour, and the limited availability of operational and incident data. This paper presents a probabilistic method developed to assess risk associated with delayed ignition of hydrogen following a loss of containment event. Unlike immediate ignition scenarios, delayed ignition represents a complex hazard influenced by the presence and density of ignition sources, time-to-ignition, and evolving dispersion behaviour. Additionally, a generalised risk framework is presented, applicable for all hazard types, with a focus on addressing individual and societal risk in pipeline design. The framework was applied to the design of a hydrogen pipeline. The risk of fatalities and injuries were superimposed across a range of loss-of-containment scenarios along the pipeline route. Results showed that although explosion events had the potential for higher consequences, thermal radiation from ignited jet fires often represented the dominant risk driver, particularly in areas with lower population and ignition source density. These insights have important implications for route selection, emergency response planning, and stakeholder engagement. The methods presented offer structured guidance for evaluating and mitigating hydrogen pipeline risks, contributing to the development of safe design practices as best-practice frameworks continue to evolve.

System failure in large-scale hydrogen-based installations such as electrolysers, fuel cells and storage facilities, may cause the formation of explosive hydrogen–air–steam mixtures. An in-depth understanding of the hazards of such mixtures under conditions pertinent to electrolysers, fuel cells (temperatures between 50 °C and 80 °C and pressures between 20 and 40 bar) and storage facilities is required before hydrogen-based installations can be designed and constructed. In this study, detonation properties of hydrogen–air–steam mixtures (e.g., detonation cell size) and their flame dynamics features (e.g., flame acceleration, runup distance, and deflagration-to-detonation transition “DDT”) were investigated experimentally and numerically to gain a more in-depth understanding of their hazards. While our results confirm the findings of previous studies in terms of the cooling effects of steam on detonation, we found that operating pressures between 20 and 40 bar counteract the effect of steam, making the hydrogen–air–steam mixture more detonable. This is particularly evident from the experimental data on detonation cell size and runup distance at pressures greater than 20 bar.

Hydrogen is a promising energy carrier for a sustainable society, and large-scale storage tanks are crucial for its widespread utilization. However, the safe storage of hydrogen poses significant challenges due to its unique hazards including embrittlement and high flammability. Among various hydrogen storage methods, the use of methylcyclohexane (MCH) and toluene as organic chemical hydrides has practical advantages such as compatibility with existing oil storage infrastructure and the ability to store hydrogen safely under ambient conditions. Despite these advantages, the risks associated with large-scale storage of these chemicals have not been sufficiently evaluated. One critical concern is the domino effect that an initial incident triggers secondary events in adjacent tanks leading to an escalation of the overall hazard. Given that multiple tanks are often installed in close proximity, dynamic risk analysis of a fire-induced domino effect involving both spatial and temporal dependencies is significant. The purpose of this study was to conduct dynamic risk analysis of the domino effect in large-scale toluene storage. First, the thermal impact of a toluene pool fire was simulated using the ALOHA software to assess its consequences on neighboring tanks. Next, the spatial and temporal propagations of the fire was modeled and analyzed using a dynamic Bayesian network. Based on these analyses, we proposed and evaluated risk reduction measures to enhance the safety of large-scale toluene storage tanks.