The chemical erosion of amorphous hydrogenated carbon films by thermal and energetic hydrogen (deuterium) impact has been studied using atomic and ion beam techniques. The samples were produced during the routine carbonization procedure in TEXTOR as well as in a simulation vessel. Energetic hydrogen ions react with these films forming predominantly CH//4 with smaller contributions of higher hydrocarbons. The temperature dependence of the erosion is similar to that of the reaction with thermal atoms. The overall reaction rate is only about twice that of thermal hydrogen exposure. These results agree reasonably well with measurements on the erosion of carbonized TEXTOR surfaces by particles from a RG-glow discharge in hydrogen.