For drinking water systems, what characteristic must solders have to be compliant with safety regulations?

For drinking water systems, solders must be lead-free to comply with safety regulations. The prohibition of lead in solder is rooted in the health risks associated with lead exposure, which can occur when lead-containing solder leaches into drinking water. Many jurisdictions have established standards and regulations aimed at minimizing lead exposure, particularly in drinking water applications where vulnerable populations, such as children and pregnant women, may be affected.

Using lead-free solder helps ensure that the water remains safe for consumption and reduces the risk of health hazards associated with lead poisoning. In contrast, solders that contain lead would not meet these safety regulations and could lead to serious public health implications. While copper as a material is commonly used in pipes and fittings, and soldering temperatures can vary, these factors are more relevant to the joining process itself rather than the regulatory status of the solder in relation to safety for drinking water systems.