Permanent chemical marker and identification of information in polymers

The invention relates to a process for chemical marking and identification of information in polymers and additives, such as ageing additives, thermal stabilizer additives, light stabilizer additives, plasticizer additives or flame retardant additives and dyes and other high-value additives. The marking is effected by the use of defined atomic masses in the form of isotopes of suitable elements in chemical compounds which are incorporated into the polymer matrix and anchored during the production. The result is a chemical code which can be recalled over the entire product life without adversely affecting the properties of the polymer through high concentrations of extraneous substances. It is possible by this process to trace back the origin of a polymer, to detect possible mixtures with chemically identical products from other manufacturers, or to clarify at a later stage whether an additive has been added in the concentration specified.