Quantifying lead (Pb) leaching from galvanized handpump spouts, leaded brass taps, and stainless-steel alternatives using the NSF 61 test protocol: Implications for safe rural water supply

Kyle Rezek , Michael Fisher , Timothy Purvis , Aaron B. Salzberg , Solomon Minyila , Siddhartha Roy 

Lead (Pb) is a neurotoxin with no known safe level of exposure. Widespread lead contamination has been found in rural groundwater-supplied drinking water systems in low- and middle-income countries, potentially from corrosion of lead-containing materials such as galvanized steel and brass. National Sanitation Foundation (NSF) 61 is an international standard for certifying the safety of water system components in contact with drinking water based on their capacity to leach chemical contaminants, especially lead, into drinking water. Another standard, NSF 372, certifies the material composition of drinking water system components as ’lead-free' if lead content is ≤0.25% by weight for wetted surfaces. This work investigates the lead leaching potential of components frequently used in these systems and explores potential alternatives to determine which components can be safely used in drinking water systems. Galvanized handpump spouts and leaded brass taps of types widely used in rural water systems in Ghana and stainless-steel alternatives, were tested against NSF 61 and NSF 372 standards. Lead-free PVC pipe segments were used as controls. Test results indicated that all stainless-steel components and PVC controls met NSF 61 and NSF 372 standards while galvanized spouts and brass taps did not meet either. The average lead levels leached over the experiment period from the brass taps, galvanized spout, stainless-steel taps, PVC pipes, and stainless-steel spouts were 192 (SD=89), 34 (SD=3), 0.3 (SD=0.1), 0.2 (SD=0.3), and 0.1 (SD=0.1) µg/L, respectively. Overall, the use of lead-containing galvanized handpump spouts and brass taps should be avoided in water systems due to their lead leaching potential; alternative products made from lead-free materials such as stainless steel should be substituted.