Even though copper is the most popular choice for use in busbars, and used very often in other electrical applications because it is more resistant to rust and corrosion than other metals, this doesn’t mean that it won’t oxidize over time.

When metals oxidize, the resistance in the conductive metal will increase, requiring more power to be used to carry current along the surface. When the copper oxidizes beyond a certain point, the metal can begin to flake and fall apart.