Evaluation of lead release potentials of commercially available premise plumbing materials

Commonly used premise plumbing materials such as pipes, valves, fittings and faucets are made of various materials, including stainless steel, copper, brass and plastic. Lead pipe has been banned for conveying drinking water in new constructions in many countries since the 1980s. Due to its flexibility and malleability, however, lead is still commonly used as an additive in these materials and may potentially leach into drinking water. The objective of this study is to investigate the likelihood of lead leaching from commonly used premise plumbing materials into drinking water. The maximum lead leaching potential for each pluming material was operationally determined using high strength acidic EDTA solutions (pH 4, EDTA = 100 mg/L). Lead leaching from each plumbing material was also evaluated using reconstituted tap water. Surface lead weight percentage obtained using SEM-EDX and lead weight percentages of the material body obtained using strong acid digestion were found to positively correlate with lead release. In general, lead release was found to follow the following order in terms of different materials: brass >> stainless steel ~ copper ~ PVC. In addition, lead release was found to positively correlate with the weight percentage of lead on the inner surfaces and in the whole body of the materials.