This Technical Specification gives guidance for the assessment of conformity of compounds / formulations, products and assemblies in accordance with the applicable part(s) of EN 13476-1, EN 13476-2 and EN 13476-3 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.It is recommended that the quality management system conforms to or is no less stringent than the relevant requirements to EN ISO 9001:2008 [1].If third-party certification is involved, it is recommended that the certification body is accredited to EN 45011 [2], EN 45012 [3] or EN ISO/IEC 17021 [4], as applicable.In conjunction with EN 13476-1, EN 13476-2 and EN 13476-3 (see Foreword) this document is applicable to Plastics piping systems for non-pressure underground drainage and sewerage - Structural-wall piping systems of unplasticized poly(vinyl chloride) (PVC-U), polypropylene (PP) and polyethylene (PE):- for non-pressure underground drainage and sewerage outside the building structure (application area code "U") reflected in de-marking of products by "U", and - for non-pressure underground drainage and sewerage for both buried in ground within the building structure (application area code "D" and outside the building structure (application area code "U") reflected in de marking of products by "UD".