The identification of plastics is important for a recycling process, but since also a lot of different additives are used in plastics like poly(vinyl chloride), it is necessary to analyse their heat-stabilizer systems due to legal regulations. A method is described to identify heavy metals containing heat stabilizers in PVC. Along with classical tests infrared spectroscopy is used. The procedures are evaluated with respect to their suitability as analysis methods for heat-stabilizers in PVC; some methods are developed to obtain the metals calcium, barium, cadmium, zink, lead and tin in a form in which they can be analysed, because only the infrared spectroscopy is able to use the samples in unchanged form.