Similarly to other fuels, as natural gas or petrol, security is one of the prime issues to be considered when handling hydrogen. Security is a crosscutting matter that must be considered at any stage of the use of hydrogen as an energy carrier, this is: production, transport, storage, distribution and final use. This is why normative, standards, technical specifications, codes of practice and regulations on hydrogen and fuel cells are required. Some of those regulations can be found by following the links below:

Pure hydrogen combustion produces, exclusively, heat and water. As no carbon is produced and the water is vaporized into steam absorbing large amounts of heat, hydrogen fire transfers less heat to the surroundings than hydrocarbon fuel fires.
Hydrogen has a wide flammability range (concentration in air between 4% and 74% by volume) and very low minimum ignition energy (0.02 mJ). For example, at concentrations below 10%v the ignition energy increases up to the ignition energy values of natural gas or petrol, which are widely used in everyday applications and solutions nowadays..

Hydrogen has a lower explosion risk rather than other fuels as it becomes explosive for concentrations in air between 18.3%v and 59%v while petrol vapour may explode at concentration levels slightly above 1%v. Furthermore, while hydrogen tends to disperse very quickly upwards into the atmosphere, propane, petrol vapour and other heavier gases accumulate close to the ground surface increasing, therefore, the risk of explosion.
Finally, it is important to remind that hydrogen is not toxic, is not a contaminant, it does not stain or smell, and, with current available technology, it doesn’t harm the environment.