This Technical Specification provides guidelines for the assessment of the durability of geosynthetics, the object of which is to provide the design engineer with the necessary information, generally defined as changes in material properties or as partial safety factors, to ensure that the expected design life of a geosynthetic can be achieved with confidence. This Technical Specification is not applicable to products designed to survive for only a limited time, such as erosion-control fabric based on natural fibres, or geotextiles for asphalt reinforcement. This Technical Specification is applicable to the durability of the geosynthetics and not to the durability of the geotechnical structure as a whole. NOTE The calculation of reduction factors for soil reinforcement applications is described in ISO/TR 20432.