Air pollution and traffic congestion are two of the major issues affecting public authorities, policy makers and citizens not only in Italy and European Union but worldwide; this is nowadays witnessed by always more frequent limitations to the traffic in most of Italian cities, for instance.

Hydrogen use in automotive appears to offer a viable solution in medium-long term; this new perspective involves the need to carry out adequate infrastructures for distribution and refuelling, and consequently the need to improve knowledge on hydrogen technologies from a safety point of view.In the present work possible different configurations for gaseous hydrogen refuelling station has beencompared: "stand-alone" and "multi-fuel".

These two alternative scenarios has been taken into consideration, each of one with specific hypotheses: "stand-alone" configuration, based on the hypothesis of a potential model consisting of a hydrogen refuelling station composed by on-site hydrogen production via electrolysis, a trailer of compressed gas for back-up, compressor unit, intermediate storage unit and dispenser. In this model it is assumed that no other refuelling equipment and/or dispenser of traditional fuel is present in the same site.

"Multi-Fuel" configuration, where it is assumed that the same components for hydrogen refuelling station are placed in the same site beside one or more refuelling equipment and/or dispenser of traditional fuel. Comparisons have been carried out from the point of view of specific risk assessment, which have been conducted on both the two alternative scenarios.