Innovation in risk mitigation: Hydrogen fire safety 

Investment in hydrogen is growing globally as countries and organizations recognize its potential in the transition to a low-carbon economy. As this versatile energy source gains traction across various sectors—energy, transportation, and manufacturing—it’s essential to focus on robust fire protection measures due to hydrogen’s unique characteristics. While hydrogen holds great promise for clean energy, it also presents specific safety challenges. 

While hydrogen presents significant potential, there are specific fire hazards that need to be managed. 

Flammability. Hydrogen’s low ignition energy makes it highly flammable, even at low concentrations. Invisible flames further complicate early detection. 

Leak risks. Due to hydrogen’s small molecular size and high diffusivity, the risk of leaks exists. Proper leak detection and gas detection systems are crucial. 

Vapor cloud explosions (VCE). Hydrogen can cause vapor cloud explosions in confined or semi-confined spaces. Understanding explosion dynamics is essential for safety. 

Ignition sources. Common sources of ignition in hydrogen environments include electrical equipment and static discharge. 

Most hydrogen failures occur in piping, fittings, and valves, as well as in hydrogen storage and vehicle fueling systems [1]. Conducting a failure rate analysis in the industry and performing consequence analysis provides accurate predictions for future incidents and allows for preventive measures to mitigate catastrophic events. 

 

Regulatory standards and framework 

There are several standards that serve as a basis for design and play a crucial role in ensuring safe hydrogen deployment and use. However, while these standards provide a robust foundation, they are not exhaustive. Additional consequence design is essential to address the specificities and inherent risks of each unique project. 

Standards serve as the bedrock of any engineering discipline, providing guidelines and best practices for safe and effective project execution. In hydrogen, standards such as the BQN standard (CAN/BNQ 1784-000/2022) set out installation requirements for hydrogen generation and for stocking equipment. NFPA 2—the hydrogen technologies code—addresses safe handling of hydrogen and offers comprehensive framework for design, construction, and operation, with separate standards that specify safety requirements for fueling stations and provide requirements for the storage, use, and handling of hydrogen. 

Because hydrogen projects are often diverse and complex, spanning several applications, standards cannot cover every potential scenario or unique challenge. This is where quantitative risk management comes into play. Consequence modeling is a proactive approach that goes beyond adherence to standards. It involves a thorough risk assessment, and the development of mitigation strategies tailored to the specific conditions and challenges of a project. For hydrogen deployment, this means considering factors such as site-specific environmental conditions, the scale of hydrogen use, and the proximity of populated areas or other critical infrastructure. In other words, each project must be evaluated for its own merits, with consequence design ensuring that all unique risks are addressed. 

This approach not only enhances safety but fosters innovation as engineers develop solutions that push the boundaries of what is possible. For example, a hydrogen fueling station in a densely populated area may need enhanced leak detection systems and robust emergency response plans, while a hydrogen storage facility in an earthquake-prone region may require advanced seismic design that goes beyond standard requirements. 

 

Fire detection, mitigation, and suppression 

As much as projects benefit from the collective wisdom embedded in standards, they must also be equipped with effective fire protection measures. These include a combination of cooling, isolation, and early detection: 

• Water as a cooling agent. Water is the most suitable fire protection agent for hydrogen fires. It primarily cools the fire rather than extinguishing it completely, preventing its spread and minimizing damage. 
• Isolation and shut-off valves. The most effective way to extinguish a hydrogen fire is to shut off the flow of hydrogen. Automatic shut-off valves play a vital role in limiting the fuel supply during a hydrogen fire. Isolating the hydrogen source prevents escalation. 
• Early detection. Implement proper detection systems, including leak detection and gas detection. Thermal imaging cameras and flame detectors are crucial to verify the presence of a flame, and swift action can prevent a small fire from becoming a major incident. 
• Hazardous area classification. Proper hazardous area classification can reduce ignition risks. 

Proper zoning and segregation within facilities can decrease ignition sources for hydrogen. Separating hydrogen storage areas from other sensitive zones reduces risks and having a well-prepared emergency response plan and continuous personnel training contribute significantly to overall safety in hydrogen plants. 

To do this, it is vital to tailor a comprehensive emergency response plan to hydrogen-related incidents. Consequence modeling data obtained during the design phase can be used as valuable input and can include geographical information on hydrogen dispersion and heat release rates resulting from jet fires, pool fires, and flash fires. This data helps determine escape route master point locations and specific personal protective equipment (PPE) requirements. It is also critical to cover diverse scenarios and to outline procedures for evacuation, communication, containment, and coordination with emergency services. 

What is next? 

The global energy landscape is rapidly evolving, with hydrogen emerging as a pivotal element in our journey toward sustainability. However, the deployment and utilization of hydrogen poses significant safety challenges that must be meticulously addressed to harness its full potential. Proactive consequence modeling ensures that hydrogen projects are safe, resilient, and sustainable, and at Hatch, we are always working with innovation in safety at the forefront. Contact us to discover more about our hydrogen solutions for global challenges and our commitment to prioritizing safety in our initiatives.