Safety-Barrier Diagrams for Documenting Safety of Hydrogen Applications

Safety-barrier diagrams have proven to be a useful tool in documenting the safety measures taken to prevent incidents and accidents in process industry. In Denmark they are used to inform the authorities and the nonexperts on safety relevant issues as safety-barrier diagrams are less complex compared to fault trees and are easy to understand. Internationally there is a growing interest in this concept with the use of so-called “bowtie” diagrams, which are a special case of safety-barrier diagrams. Especially during the on-going introduction of new hydrogen technologies or applications, as e.g. hydrogen refueling stations, this technique is considered a valuable tool to support the communication with authorities and other stakeholders during the permitting process. Another advantage of safety-barrier diagrams is that there is a direct focus on those system elements that need to be subject to safety management in terms of design and installation, operational use, inspection and monitoring, and maintenance. Safety-barrier diagrams support both quantitative and qualitative or deterministic approaches. The paper will describe the background and syntax of the methodology and thereafter the use of such diagrams for hydrogen technologies are demonstrated.