Overview

Building equipment is the main application of metallic materials in the field of water supply. Contact between metallic materials and drinking water can cause metal release to the water. This release is caused by corrosion of any metal films or layers present on the products or the bulk material. Metal release from the bulk material depends on the composition of the material; this process can persist over a long period. This long term behaviour depends on the formation of protective layers of corrosion products on the surface of the material. It is possible to test materials to assess their behaviour in releasing metals from the bulk material so that products made of accepted materials do not have to be tested for this characteristic. The metal release from metal layers depends on the type of coating and certain characteristics of production processes. The test method described in this standard is designed to provide information on nickel release over time from surfaces of products having a coating containing nickel which are in contact with drinking water. This nickel coating may be added intentionally or part formed unintentionally, that means, it might appear due to electrostatic conditions in the process. For testing nickel release caused by the bulk material the test procedure according to EN 15664-1 and -2 is required. This test is based on EN 15664-1 and includes alternating periods of once-through flow and stagnation in a rig, simulating the conditions in a domestic distribution system. For the commonly used chrome plating process of sanitary tap ware, preliminary research indicates that the water composition does not significantly influence the release of nickel from such surface nickel layers. The use of this method in product testing might give more information about the influence of water composition. If this test method is used to measure the release of other metals it must be taken into account that the water composition has a strong influence on the results. This standard has been prepared by CEN/TC 164/WG 3 "Effects of materials in contact with drinking water" (secretariat: NEN, Netherlands) under the chairmanship of members of NA 119-04-14 AA "Werkstoffe und Bauteile in Kontakt mit Trinkwasser" ("Materials and products in contact with drinking water") at NAW.

Document: references other documents

Document: referenced in other documents

Responsible national committee

NA 119-07-09 AA - Materials in contact with drinking water  

Responsible european committee

CEN/TC 164/WG 3 - Effects of materials in contact with drinking water