Leachability of Lead from Selected Copper-Base Alloys

Abstract

The Bureau of Mines has conducted research on the selective leaching of lead from copper-base alloys in highpurity water. The alloys in this study were selected as representatives of those used in various plumbing system fixtures such as faucets and valves. Leaching tests were conducted for a total period of 14 days and at temperatures of 25, 50, and 75°C. An acetic acid pretreatment was used in an effort to reduce the amount of lead that was leached from the alloys. The results show that, with the exception of the more complex yellow brasses, more lead is leached into water from alloys containing greater concentrations of lead and that the rate of lead leaching decreases with exposure time. Higher temperatures had relatively little effect on the leaching of lead. Lead was preferentially dissolved from all of the alloy groups. Of the small total amount of alloy dissolved, more Pb, 10 to 59 times, was dissolved than would be predicted from the proportional quantity of Pb present in the alloy (0.1 to 7.0 wt% Pb). Typically, the amount of Pb dissolved in any given test period exceeded the Environmental Protection Agency proposed action limit of 0.015 mg/L.

The pervasive threat of lead (Pb) in drinking water: Unmasking and pursuing scientific factors that govern lead release

“…A lessons learned approach is also an inadequate way to predict soluble Pb release under future circumstances, as it requires extrapolations in order to forecast behavior at some other location outside the existing database of knowledge. Furthermore, there is no direct way to differentiate all of the potential sources and origins of Pb contamination in drinking water systems: municipal service lines, household plumbing, solder joints, and Pb-containing brass fixtures ( 22 ) (as well as faucets and water meters) ( 23 ).…”

“…While removing Pb plumbing is of obvious merit, many sources of Pb can remain. Pb-based solder is used to connect piping, and Pb is present in trace amounts in Cu-rich alloys and disproportionately, preferentially leaches out into drinking water in greater quantities than predicted by the content of Pb in the alloy ( 22 ). There is a significant amount of Pb trapped in the oxides on iron pipes as well ( 3 , 31 – 33 ).…”

Lead in Bottled Waters: Contamination from Glass and Comparison with Pristine Groundwater

“…For comparison, the tap water in Bammental that had been bottled commercially in PET(E) yielded an average of 119 ± 17 ng/L ( n = 3), and the tap water from a household in Bammental, after flushing for 1 h, was 223 ± 4 ng/L Pb ( n = 3). The difference between the tap water bottled in PET(E) and that obtained from a household faucet may reflect Pb contributions from any number of sources in the water supply system, including steel and copper pipes, lead solder, and brass valves ( − ). These measured concentrations, however, are not only well below the drinking water standards for Pb cited earlier but often less than the Pb concentrations found in bottled waters in glass containers (Figure ).…”