GPO vulcanizates have a different property profile than sulphur vulcanizates of ETER. Althoung GPO has the same excellent hert and ozone resistance, the same high elasticity and good dynamic properties of ETER,it has poorer swelling resistance in oils, and praticularly in motor fuels. The low temperature flexibility ofwater and alcohol is good. Since they do not contain chlorine,PO and GPO have a poor flame resistance