1. ASTM D 1435-99: standard practice for outdoor weathering of plastics.
2. ISO 179: plastics—determination of charpy impact strength, 1993.
3. ASTM E 178-94: standard prectice for dealing with outlying observations.
4. EN 513: unplasticized polyninylchloride (PVC-U) profiles for fabrication of windows and doors—determination of the resistance to artificial weathering 1998.
5. EN 12 608: Unplasticized polyninylchloride (PVC-U) profiles for fabrication of windows—classification, requirements and test methods, 1998.