The doctoral study closes a number of knowledge gaps in hydrogen safety engineering related to the safety of hydrogen storage cylinders. The main targets of the work were achieved by applying analytical and contemporary numerical methods, including computational fluid dynamics (eFD). The models developed within the scope of the study were compared with experiments and allow for prediction of fire resistance rating (FRR) of high-pressure gas storage tanks and prediction of one of the dangerous effects from tank rupture in a fire, i.e. blast wave decay. The numerical model for prediction of the FRR of a high-pressure hydrogen storage tank in a fire was developed and compared with experiments with good agreement. The numerical pretest studies performed revealed the effect of HRR variation which significantly influenced the FRR of the hydrogen storage cylinder that were implemented into the experimental programme and were further proved in experiments. A theory for the prediction of blast wave decay from gas vessel rupture in a fire was developed and validated against experiments with stand-alone and under-vehicle (on-board) tank rupture experiments. It included a novel analytical model for the prediction of blast wave decay which accounted for effects of a real gas and effects from hydrogen combustion. Engineering tools (nomograms) for first responders and hydrogen safety engineers were developed. The engineering tools allow for prediction of hazard distances for humans and buildings from a blast. The suggestions for amendments of the Global Technical Regulation No. 13 and safety strategies were formulated.