This document provides a qualitative method for the identification of rubbers by their pyrolysis products using tandem gas-chromatography/mass spectrometry. The method applies to rubbers in the raw state and to unvulcanized and vulcanized compounds. Compounds can be based on a single rubber or a blend of two or more rubbers. Where the level of a particular rubber in a blend is <10 %, detection and identification can be difficult. A non-restrictive list of rubbers is given in Clause 4.