Abstract: A security apparatus (10) is provided in an enclosed area to be secured against an external threat, e.g. a load volume of a vehicle transporting valuables is secured against unauthorized entry. Two chemical components are contained separately. When a danger situation occurs, the security apparatus (10) is actuated via control means to expose the chemical components to each other and to mix them. After a predetermined, short, time period, the mixture is released and is distributed over the area being secured. Foaming and solidification take place in short time to occupy the enclosed area and to prevent entry and exit.