This document gives requirements and guidance for the assessment of conformity of formulations, products and assemblies in accordance with EN 1401-1 intended to be included in the manufacturer s quality plan as part of the quality management system and for the establishment of third-party certification procedures. NOTE 1 The quality management system is expected to conform to or is no less stringent than the relevant requirements to EN ISO 9001 [1]. NOTE 2 If third party certification is involved, the certification body is expected to be compliant with either EN ISO/IEC 17065 [2] or EN ISO/IEC 17021-series [3], as applicable. NOTE 3 In order to help the reader, a basic test matrix is given in Annex A. In conjunction with EN 1401-1, this document is applicable to piping systems made of unplasticized poly(vinyl chloride) (PVC-U) intended for non-pressure underground drainage and sewerage: buried in ground outside the building structure (application area code U ); both buried in ground within the building structure and outside the building structure (application area code UD ).