Hydrogen has not only the potential of tackling climate-related issues by replacing fossil fuels, but it also plays a main role in the energy transition which will have several geopolitical implications. According to the International Renewable Energy Agency (IRENA), relations between countries and communities will be transformed by “a new energy age” changing the concept of power, security, energy independence and prosperity. For these reasons, the interest in hydrogen recently skyrocketed as shown by the hydrogen strategies developed by many countries in the world. This will result in a considerable increase of hydrogen produced, stored, and consumed worldwide in the near future. Safety aspects must always be considered during the whole hydrogen lifecycle. The aim of this study is to pinpoint the consequences of failure for hydrogen technologies and the most common types of techniques developed and validated to assess them. Different types of models including theoretical and numerical ones were adopted to assess these consequences in the past. The advantages and drawbacks of these types of techniques are highlighted in this work. The intent is to provide critical insights to analysts carrying out the risk assessment in order to improve the overall safety of hydrogen technologies.