The diploma thesis deals with determination of volatile products during the thermal loading of polyurethane foams, focusing mainly on mounting foam, low expansion foam and fire foam. The main object of the thesis is to observe the physical changes of these samples at thermal loading and analyze the volatile products arising. Sampling of arising product progress at temperature of 250 ° C, 200 ° C and 150 ° C for 10 minutes. At higher temperatures the samples changed the color to black with more smoke than at lower temperatures. Physical changes that occurred during heat load were recorded to the tables. Subsequently, the samples were analyzed by gas chromatography using the GC-MS method. After analyzing the samples, we found that main produced products were toluene, xylene and ethylbenzene. The values of these products were processed to the table.