The Technical Reference for Hydrogen Compatibility of Materials summarizes materials data related to hydrogen-assisted fracture (also called hydrogen embrittlement) in gaseous hydrogen environments, with emphasis on hydrogen permeation and structural properties. The Technical Reference generally does not provide specific recommendations for materials selection as the suitability of a given material depends on service conditions, in particular the mechanical and environmental conditions associated with a particular component, as well as the details of the materials microstructure. In substance, the Technical Reference is a collection of stand-alone documents organized by materials class, which have been compiled into this composite report. The individual sections are occasionally updated and new sections are added; the most recent versions are available from our website at

This document addresses polymer materials for use in hydrogen service. Section 1 summarizes the applications of polymers in hydrogen infrastructure and vehicle fuel systems and identifies polymers used in these applications. Section 2 reviews the properties of polymer materials exposed to hydrogen and/or high-pressure environments, using information obtained from published, peer-reviewed literature. The effect of high pressure on physical and mechanical properties of polymers is emphasized in this section along with a summary of hydrogen transport through polymers. Section 3 identifies areas in which fuller characterization is needed in order to assess material suitability for hydrogen service.

Automakers and fuel providers have made public commitments to commercialize light duty fuel cell electric vehicles and fueling infrastructure in select US regions beginning in 2014. The development, implementation, and advancement of meaningful codes and standards is critical to enable the effective deployment of clean and efficient fuel cell and hydrogen solutions in the energy technology marketplace. Metrics pertaining to the development and implementation of safety knowledge, codes, and standards are important to communicate progress and inform future R&D investments. This document describes the development and benchmarking of metrics specific to the development of hydrogen specific codes relevant for hydrogen refueling stations. These metrics will be most useful as the hydrogen fuel market transitions from pre-commercial to early-commercial phases. The target regions in California will serve as benchmarking case studies to quantify the success of past investments in research and development supporting safety codes and standards R&D.

Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. Approved for public release; further dissemination unlimited.

This report summarizes the investigation of the release of approximately 300kg of hydrogen at the AC Transit Facility in Emeryville, CA. The hydrogen release was avoidable in both the root cause and contributing factors. The report summarizes the findings of the incident investigation and metallurgical analysis of the failed valve. Hydrogen embrittlement, manufacturing quality as well as miscommunication played significant roles in the event. No injuries or fatalities resulted from the incident.