Life-cycle impacts of lead and lead-free solder used in wave soldering of electronics

Results from a joint US EPA and US electronics industry-funded life-cycle assessment of lead and two lead-free alternative solders are presented. Impact scores are reported in 16 different environmental categories for wave soldering applications. Bar solders evaluated include tin-lead, tin-silver-copper, and tin-copper. Tin-lead solder was determined to have higher impact scores than the lead-free solders in four categories, while having lower impacts in five. The use/application stage was the dominant contributor to most impact categories, while upstream and end-of-life processes also made significant contributions to specific impact categories, depending on the solder. Sensitivity analyses of the effect of silver production as well as landfill leachate data are also presented.