We note that, due to very high heat effects of hydrolysis Reactions 1 and 2, the upscale of hydrogen-generating processes based on them is associated with a high probability of thermal runaway which must be avoided. To get such an opportunity, it is necessary to quantify influence of several factors (temperature of the reaction solution, concentration of the solute, pH, etc.) on the kinetics of hydrolysis of Mg and MgH2 followed by a suggestion of efficient ways of their control, not only towards acceleration of the hydrolysis reaction (that is subject of most of the published works on the topic) but also slowing it down when necessary. Our work contributes into filling this knowledge gap by the detailed quantitative studies of the influence of composition and morphology of the hydrogen-generating material, type of the applied organic acid, its concentration in the solution, and pH on the yield and rate of the hydrolysis reaction.