Owing to its iron content, human blood smells like metal to many people. In fact, when people rub their skin along certain iron-containing objects, such as coins, perspiration reacts with the iron to produce a metallic smell, according to LiveScience.com.

The fact that humans smell iron when touching something made of iron is likely a result of the evolutionary sense for a smell of blood, reports LiveScience.com. It is also a result of metal-induced oxidation of oils in the skin. People are smelling is their own blood through their skin rather than the iron in the objects they are touching.