Electronic scrap. Pile of discarded electronic components ready for recycling. Modern electronic equipment contains many recoverable elements, including some precious metals such as gold, silver, platinum and palladium. Recycling these components allows these metals to be reclaimed and reused. Electronic components may also contain potentially polluting substances, such as lead, cadmium, mercury, barium and various plastics. To prevent environmental damage these substances are reclaimed and either destroyed or reused.