Navigating Unfamiliar Territory—US Hydrogen Safety Regulations and European Standards

Developers of hydrogen technology projects are interested in reaching as many customers as possible. The EU’s hydrogen strategy and REPowerEU projects, as well as the funding available through the US government’s Inflation Reduction Act are expected to boost hydrogen-related projects on both sides of the Atlantic. However, manufacturers, project developers and engineers need to be aware of local safety standards and regulation as they bring their products to the market.

European manufactures, developers and engineers looking to reach US customers may face an unfamiliar regulatory and standards regime. In our presentation, we will provide a brief overview of key US government regulators for safe handling of hydrogen. We will also review relevant US standard organizations with which Europeans designers may not be familiar, including ASME, NFPA, and CGA.

A more in-depth case study compares the European and US standards for the design of deflagration vents, EN 14994 and NFPA 68. Deflagration vents are an established technique for preventing catastrophic explosions and enclosure failures after a flammable fuel-air mixture is ignited. Sizing these devices for hydrogen presents a unique challenge due to hydrogen’s combustion properties including a fundamental burning velocity that is almost 10 times higher than more conventional hydrocarbon fuels. Burning velocity and K_G (deflagration index for gases) are important parameters when sizing deflagration vents. The high burning velocity, and corresponding high K_G, of hydrogen can limit the effectiveness of explosion vents to mitigate hydrogen explosions. In this paper, we will compare these different approaches for sizing such devices, namely NFPA 68 and EN 14994 for several case studies.