What type of solders and fluxes should be used for soldered joints of copper water supply piping?

Lead-free solders and fluxes are the correct choice for soldered joints in copper water supply piping due to health and safety regulations. The use of lead in plumbing materials has been restricted or banned in many places because lead can leach into drinking water, posing serious health risks. Lead-free solders, typically made from a combination of tin, copper, and other metals, comply with safety standards set by organizations such as the Environmental Protection Agency (EPA) and the American National Standards Institute (ANSI).

In addition to health considerations, lead-free solders perform well under the conditions typically encountered in plumbing systems. They provide a strong, durable joint that maintains the integrity of the piping system without introducing harmful contaminants into the water supply. The adoption of lead-free materials aligns with modern plumbing practices that prioritize public health and safety.

Other types of solders, such as lead-based, are no longer permissible for use in potable water systems due to their toxicity. Copper-alloy and iron-free materials might have their applications, but they are not specifically designed for soldering joints in copper water supply piping, where lead-free options are explicitly recommended.