Abstract: In the manufacture of synthetic foams and also especially in that of timber materials using urea-formaldehyde condensate binders, the mol ratio between urea and formaldehyde is decisive for the resultant final rigidity and the presence of free gaseous formaldehyde. In order, with a favourable mol ratio, to reduce the quantity of gaseous formaldehyde remaining in the timber material and at the same time to obtain effective fire resistance in both synthetic foams and timber materials adhesively secured with isocyanate, the invention proposes a combination of effective substances to be added to the initial raw materials as a granulate with a grain size of 80 to 1,500 my.