Rising concerns over carbon emissions from fossil fuels have fueled interest in renewable energies. Hydrogen, as a clean energy source, stands out for its free of pollution and high calorific value. However, challenges in safely storing and transporting hydrogen, such as embrittlement, fire and explosion risks, are critical. This study reviews hydrogen storage and transportation safety research through a bibliometric approach, analyzing 948 relevant publications obtained from the Web of Science Core Collection, SCOPUS, and Science Direct literature databases since 2007. Then, a bibliometric analysis is conducted to obtain the publication's distribution, organization, source, and cooperation networks. Besides, the research hotspots in different periods are identified, and the evolution trend of hot topics is analyzed. Moreover, this paper proposes the possible future research needs in this field. The main hot topics in the field of hydrogen storage and transportation safety research include microstructure, crack, susceptibility, and hydrogen embrittlement and they change over time. In the future, research topics such as hydrogen damage in materials, compatibility of hydrogen in natural gas pipelines, and risk assessment should obtain more attention.

The rapid industrialization and urbanization in China require a high level of safety management and thus urge the development of safety risk assessment in China. In the past two decades, many safety risk assessment research findings have been published in international journals by Chinese scholars, while it is not clear the development progress and China's contributions to the world in this research field. Therefore, a systematic and thorough literature review is conducted to investigate risk assessment research in China. Firstly, the research publications authored by Chinese scholars are searched from the well-known literature database Web of Science to support the analysis of risk assessment research in China. Secondly, a bibliometric analysis is conducted for the obtained literature related to risk assessment research in China to find out publication trends, research organizations, research authors, research topics, and research methods. Then, a thorough analysis of research topics and research methods is carried out to present the research progress. Finally, possible future research issues in the risk assessment research domain are discussed based on this literature review. According to the discussion, more attention in China should be paid to the risk of digital or autonomous systems, the risk related to extreme events, and the risk in large cities.