The Scientific Reason Coins Make Your Hands Smell

In today's times, it's a rare thing to be dealing with cash. You most likely do your banking on your phone and pay for everyday purchases with a card or through a website. And if paying with cash is rare, having exact change is even less likely. Coins are bulky and annoying to count and keep track of, and if you've handled them at all, you've probably noticed they leave your fingers smelling like old metal.

But even if those other shortcomings are true, the weird smell on your hands actually isn't the coins' fault. It doesn't come from the (literally) hard currency. Your hands smell like that because of a natural reaction between your skin and certain metals, according to Mental Floss, so it can really happen with anything. That's why you won't notice the smell much until you pick the coins up. So where does the smell come from and how does the reaction work?

Where is the smell coming from?

The reason your hands smell after touching coins is because of the oil on your skin. According to Nature, the oils on your hand react with iron molecules and undergo a chemical reaction that results in certain vaporous odors. Chemicals on your skin give ions to the atoms of the metal you're handling, according to Mental Floss, and those ionized particles cause the oils on your skin to begin decomposing. That decomposition creates the compounds that carry the distinctive smell you recognize.

The smell doesn't have anything to do with the metal itself, according to Nature. We consider it to be a "metallic" smell because it most often happens when handling metals, although the same vapors can be produced in other ways. One example is the way skin interacts with blood. Blood has iron in it, and when it meets the skin, the same chemical reaction can take place — resulting in the "coin" smell, even though no coins were handled.

How to prevent the smell

Since the smell isn't actually coming from the metal, there are some simple solutions to prevent it from happening. If you can keep the metal from coming directly into contact with your hands, for example, the chemical reaction can't take place. According to Atlanta Gold and Coin, one easy way to prevent the smell from lingering on your hands is to wear cotton gloves while you handle coins.

Wearing gloves has an added benefit, too, especially for collectors and lovers of antiques. Covering your hands can stop the smell and keep the coins in better condition in the long run. If that seems a little over the top, there's always the option of washing your hands after you've handled the metal. That's probably a good idea whether you mind the smell or not. According to North Dakota State University, money is notorious for carrying germs and bacteria.