In the nickel and chrome plating of connecting elements of flexible hose connectors, nickel sometimes also precipitates on the internal surfaces. In this project, researchers shall investigate to what extent limits in drinking water can be exceeded as a result of nickel release from the internal surfaces.
The external surfaces of the majority of commercially available domestic fittings have a polished chrome-plated finish. The sanitary fittings are connected to the water line with pipes and flexible hoses via angle valves. To ensure a uniform appearance, the majority of connecting pipes and flexible hose connectors in Germany are nickel plated.
For technical reasons, the openings are not sealed in the coating process. As the electric field also reaches inside the openings, part of the inside surfaces that come into contact with water is also coated.
In this research project, experimental comparative tests are used to investigate the release of nickel, predominantly, as well as the alloy elements, copper, zinc and lead from five kitchen taps from two different manufacturers and the supplied hose connectors with (partially) nickel-plated connectors. This long-term study was conducted according to the protocol specified in DIN 50931-1. To estimate the specific contributions of the individual installation components, sanitary fittings and hose connectors were operated and tested separately and independently of each other.
Using the results of these investigations it was possible to evaluate the release of nickel from sanitary fittings and the associated hose connectors into drinking water under defined conditions and provide basic information for amending DIN 50930-6.
Publications:
Werner, W.; Klinger, J.: Untersuchungen zur Nickelabgabe von flexiblen Anschlussschläuchen mit vernickelten Verbindern für Sanitärarmaturen [Studies on the release of nickel from flexible hose connectors with nickel-plated connections for sanitary fittings], DVGW energie|wasser- Praxis 3/2009, 67-71 (2009)
