The objectives of this chapter are to present the technical safety barriers that are used in hydrogen fueling stations and introduce methods for evaluating the performance of these barrier systems. Design principles and operational modes of technical safety barriers are discussed, followed by the introduction of failure modes. Dangerous undetected failures are the main contributor of unavailability of technical safety barriers. The chapter provides a framework of reliability and integrity assessment of such barriers in hydrogen fueling stations. Since the applications of relatively new and existing reliability information are not sufficient, reliability prediction is necessary. This chapter then employs approximation formulas and the Markov methods for integrity assessment, with case studies on pressure relief valve systems using single barrier components and 1-out-of-2 voting structures. The impact of common cause failures is also considered in the case studies.