This document defines the quality of gaseous hydrogen, i.e. its parameters and limiting values, to be transmitted, injected into and extracted from storages, distributed and utilized in fully and/or partially rededicated gas infrastructure and connected applications in a safe way. This document gives evidence to the end-user which minimum exit hydrogen quality can be expected and ensured from natural gas infrastructure as minimum requirement and without further purification. NOTE 1 The rededicated gas infrastructure can include new parts of this infrastructure constructed/added after the conversion of the natural gas grid. NOTE 2 It is expected that over time the hydrogen delivered through such pipework will improve in quality, e.g. due to the increase in share of high purity hydrogen produced by electrolysis This will be taken into account in further development of this document.