A Pilot Evaluation of Brass Faucets

摘要

A 12-month study of six commercially available residential brass kitchen faucets was conducted to determine total and particulate lead and selenium leaching at various stagnation times as well as continuous long-term simulated residential use at the Portland Water Bureau's Water Quality Laboratory. The faucets were selected to represent varying lead content and included one faucet manufactured with Envirobrass, a brass alloy with a lead content of less than 0.25%. A test of varying stagnation times found that the Envirobrass faucet and one other faucet had no detectable lead in 1-L samples for stagnation times as long as six hours, while the maximum lead concentration in the samples of the other faucets were found to be 2 μg/L, substantially lower than the 15 μg/L action level. Afterwards, a sequential sampling plan of four 60-mL samples and one 760-mL sample was used to monitor the long-term changes in lead release from the faucets. The results of the four small initial samples were compared with a separate destructive metallurgical analysis of duplicate faucets to identify specific internal faucet components that were releasing lead. The final 760-mL sample was used to obtain an aggregate 1-L sample. The maximum initial lead release from the faucets was calculated between 1 – 2 μg/L in the aggregated 1-L sample, with most faucets having lead release between an even lower 0.1 and 1 μg/L. For some faucets, very low, but detectable, lead was detected in each of the 60-mL samples, indicating that low amounts of lead was present in most, if not all, of the interior metal faucet components. For other faucets, including the Envirobrass one, the very low lead release was isolated to only one or two parts of the faucet that contained lead. The remaining faucet components had no lead and therefore did not contribute to any lead in the sampled water.