It’s been a year since the Waste Electrical and Electronic Equipment Directive and the Restriction of Hazardous Substances Directive (RoHS) have mandated that lead be eliminated from electronic systems. Consequently, this has led engineers to a high interest in using lead-free soldering alloys. Some of the harmful alloys that are used in normal soldering are tin, copper, silver bismuth, indium, zinc, and antimony.

So why are these dangerous to humans everywhere? Prior to 1930, all homes used lead pipes to transport water to and from houses. Now, most homes use copper piping. However, this is still a problem because most of these copper pipes were assembled using solder, which is approximately 50% lead. This harmful lead, whether through piping or from the solder used to blend the pipes, is especially prominent in the water a few years after installation of the pipes.

In addition to lead solder being applied in piping, it is often used in some basic household staples like canned food. Canned fruit and vegetables, canned juices, and tomato sauce are extremely likely to contain high levels of lead from the solder used to solder the tops of the cans on. In spite of these dangers, the FDA still has not banned lead solder in food packaging, but many manufacturers are taking precautions against this.