The new applications of Hydrogen as an energy vector in non industrial environments requires the revision of previously defined safety distances intended for implementation of hydrogen in industrial settings. The latter are indeed often not compatible with the integration and space constraints of the Hydrogen Energy applications ; furthermore, equipment and devices designed for such applications incorporate specific means of prevention and mitigation allowing to adopt smaller safety distances than those previously prescribed.

Sophisticated modelling tools allow a more accurate prediction of the physical effects associated to a given incident scenario than was possible previously, but this does not provide the rationale that is necessary for defining which accidents or deviations and which effects to consider for producing a set of standard safety distances in the form required for codes and standards.

Such a rationale is proposed, expanding on the framework developped by EIGA (IGC 75/07), where a safety distances is assessed using a risk based approach as a means to avoid, where appropriate, a minor incident escalating into a major incident.

Its application as performed to define the safety distances provided in the recently adopted international technical specifiaction ISO TS 20012 - Gaseous hydrogen - Filling stations , is shown.