Brass components are used for various drinking water related applications such astaps, fittings, valves, etc. Brass materials are commonly alloyed with 1-3 % lead,which acts as a lubricant during machining. However, problems with lead releasefrom brass installations to drinking water have been observed in households in Sweden,and since lead is highly toxic this may pose a threat to health. This article focuseson the different standard test methods for assessment of lead release from brassto drinking water.Three assessment methods were evaluated, representing the product tests in Scandinavia(NKB4) and US (ANSI/NSF-61:2010), and the European material test (EN15664:1-2). Furthermore the effect on lead release of chlorine washing of brass wasalso investigated. This washing is performed to remove the smeared lead layer onthe surface, originating from the machining operation.Eight materials with lead content from 0.14 to 3 weight-% were included in the study.The lead concentration in the exposure water was monitored over time and the materialswere then assessed according to the criteria specified in each standard.The study showed that results from the long-term test do not correlate with thosefrom the short term tests, indicating that different processes are involved, dependingon the operation time of the exposure. A clear tendency was observed, that lead releaseis highest and most fluctuant in the beginning of the operation time, while astabilization is observed after approximately 15-20 weeks. This pattern is observed inboth the washed and un-washed samples, indicating that corrosion processes areinvolved.The assessment of a material depends on the method and no material consistentlyfails or passes all three tests. Lead release is fluctuating dramatically during the firstweeks, resulting in low reproducibility of the Scandinavian NKB4 test.Washing of the smeared lead on the surface decreases lead release with approximately75 % in a short term test, while no positive effect is observed in a long termtest.In conclusion, the results of short term tests are highly influenced by the smearedlead on the surface of the material and cannot be used to predict the long term performanceof the material.
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