radical bromination of trially isocyanurate preference is to be given to organic solvents which can also be used for free radical bromination reactions in particular these are solvents selected from the group consisting of dichloromethane tetrachloroethane acetic acid carbon tetrachloride chloroform or mixtures of the same preferably the porous adsorbent is added to the finished tdpi reaction solution to precipitate the material in principle it is also possible to use the reverse procedure the process takes place at temperatures which permit efficient isolation of tdpi in particular within the temperature limits stated above once the adsorbent has been added stirring is generally continued for a time sufficient to complete adsorption of tdpi on the adsorbent the material may then be isolated and dried for isolation the reaction solution may be removed by distillation and the remaining solid precipitate may be further processed the present invention likewise provides a solid which is obtainable as described immediately above this solid is composed of a solid precipitate of tris 2 3 dibromopropyl isocyanurate which has been bound by adsorption on the solid porous adsorbent the solid described above may be used for providing flame retardancy to plastic products in one preferred embodiment the form in which the solid is incorporated into such products is that obtainable after isolation and drying preferably the solid is used to provide flame retardancy to polypropyene polyethylene and polystyrene and to the products produced therefrom as stated the inventive process can be used to produce tdpi which is otherwise difficult to isolate in solid form in practically quantitative yield and purity via adsorption on porous adsorbents the product is in a form which permits improved.