The influence of additives such as TiO2, Al2O3 and their mechanical mixture as well as aluminium oxide, the surface of which contains phosphorous and titanium-oxide nanostructures, on the combustibility of foam plast (trade mark PEN-I), produced on the basis of epoxide novolak block-copolymers, was studied. It was stated that the incorporation both phosphorous-containing and titanium-containing oxides in the composition results in significant (in two to five times) decreasing of the samples' combustibility. The probable mechanism of inhibition of burning process for those combustion retarders was discussed. (c) 2005 Elsevier B.V. All rights reserved.