Hydrogen and Methane have the capability to form explosive mixtures with oxygen and air which can lead to catastrophic accidents. For this reason, explosion hazards associated with the use, storage and transport of gaseous/liquid Hydrogen and Methane are a very serious problem that does not concern only the aerospace field but, because of the increasing everyday uses of these substances, also the industrial and domestic environments. The purpose of this work is to carry out a detailed investigation on the parameters and the mechanisms governing the explosion phenomena through an accurate theoretical study and a research work on the current knowledge and data.