This part of EN ISO 1452 gives guidance for the assessment of conformity of compounds/formulations, products, joints and assemblies in accordance with the applicable parts of EN ISO 1452 intended to be included in the manufacturer’s quality plan as part of the quality management system and for the establishment of 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 [1]. NOTE If certification is involved, the certification body and inspection body is preferably compliant with EN 45011 [2], EN 45012 [3] or EN ISO/IEC 17021 [4], as applicable. In conjunction with Parts 1 to 5 of EN ISO 1452 (see Foreword) this document is applicable to unplasticized poly(vinyl chloride) (PVC-U) plastics piping systems for water supply and for buried and above-ground drainage and sewerage under pressure.