O-rings made of EPDM-compounds from different suppliers were tested in a benchmark regarding their resistance against hot water up to 180°C. Next to these aging tests, TOC-content and electrolytic corrosion were examined. In the theoretical part the way to a sensible choice oftest parameters is discussed. Moreover a scoring system was established to rank the different materials in an objective way. The outcome of this benchmark is that the O-Ring material 70 EPDM 291 (Freudenberg) shows superior aging resistance against hot water up to 180°C in comparison with the other tested materials. In addition 70 EPDM 291 has a broad spectrum of drinking water approvals, it takes a leading position as a real high performance EPDM material.