Abstract: The invention relates to a system for safeguarding dangerous substances, such as fuels, in tank reservoirs, having a tank reservoir and a feed unit, which is connected to the tank reservoir and inside of which substances that bind dangerous substances are located and can be transferred into the tank reservoir. The tank reservoir and feed unit are connected to one another in such a manner and the substances that bind dangerous substances are selected in such a way that, when transferring the substances, the dangerous substance inside the tank reservoir can be physically retained in the substances, in particular, by absorption. If, at the same time, the dangerous substance inside the tank reservoir can be transferred by means of a chemical reaction into a chemically modified state that prevents the ignition thereof by increasing the flash point, the discharging of the dangerous substance from the tank reservoir and the ignition thereof are prevented in a very effective manner.