Why are lead-free tin solders used in drinking-water systems?

Lead-free tin solders are used in drinking-water systems primarily to eliminate the health risks associated with lead exposure. While traditional tin-lead alloys are common in many soldering applications, lead is a toxic heavy metal that can leach into water supplies, posing significant dangers to human health.

To address these safety concerns, specialized lead-free solders have been developed for domestic plumbing systems. These alternatives are essentially high-tin alloys that incorporate small percentages of copper or silver to maintain the necessary structural integrity and performance required for joining pipes in water systems.1