Ensuring material integrity throughout the hydrogen value chain is essential for the safe and efficient use of hydrogen and ammonia. FME HYDROGENi conducted a study to map materials in contact with hydrogen and ammonia, highlighting the importance of selecting the right materials. Hydrogen embrittlement and corrosion pose significant challenges for metallic materials, while stress corrosion cracking is a concern with ammonia. Research efforts aim to address these challenges and gather essential information on material systems and integrity issues. The study emphasizes the need for structural metallic materials to resist hydrogen embrittlement to maintain ductility and fracture properties. Challenges in production and transport include avoiding hydrogen embrittlement in steel components and protecting against corrosion due to ammonia. Similar challenges exist in end-use applications in transportation, where material lifetime and performance are critical. Designing hydrogen infrastructure requires careful consideration of factors like mechanical properties, potential impurities, and material selection to ensure long-term safety and efficiency. The study by HYDROGENi highlights known challenges and knowledge gaps, providing valuable insights for industry stakeholders.