Development and test concepts for minimizing the weight and volume displacement penalties of polyurethane foam explosion suppression systems are described. Both structural and integral isolation concepts for arrestor voiding techniques were investigated. These two approaches adjust weight and volume displacement penalties with respect to allowable fuel tank structural limits and system over-pressures. The structural isolation concept utilized natural aircraft structural compartmentization whereas the integral isolation concept used closed compartments within the foam itself in the form of hollow bodies. Flame arrestor effectiveness, fuel flow resistance and thermophysical properties of representative candidate materials and configurations are evaluated.