This article was medically reviewed by Tania Elliott, MD, who specializes in infectious diseases related to allergies and immunology for internal medicine at NYU Langone Health.
Copper kills most germs within hours, and renders others non-infectious. Nicole Lienemann / EyeEm / Getty Images
While you may think that antiseptic wipes or sprays are necessary to kill germs, there’s actually a metal that kills germs on contact — no cleaning supplies necessary.
Believe it or not, the use of copper for health purposes dates all the way back to Ancient Egypt, and scientists today are still learning about the amazing benefits of copper. Here’s what you need to know.
Copper does kill germs
Copper has antimicrobial properties, meaning it can kill microorganisms like bacteria and viruses. However, the microorganism has to come in contact with the copper in order for it to be killed. This is referred to as “contact killing.”
According to Edward Bilsky, Ph.D., Provost and Chief Academic Officer at Pacific Northwest University of Health Sciences, copper can kill germs in a few ways:
The exact mechanism of how copper interferes with proteins in bacterial cells is not fully understood yet, but the current hypothesis is mis-metalation, thanks to the fact that copper is a stable metal.
“Mis-metalation is the ability of a metal to basically replace another metal,” says Michael D. L. Johnson, Ph.D., Assistant Professor of Immunobiology at the University of Arizona College of Medicine in Tucson. “Copper can just replace some of the other metals that are present in some of these other proteins [in bacteria] and by doing so, it blocks the function of those proteins.”
When you block a protein’s function, it starts a bacteria-killing chain reaction. “By blocking the function of the protein, you block the function of the pathway. When you block the function of the pathway, you block the function of the organism, and then the organism is just dead in the water,” says Johnson.
Copper can kill viruses and bacteria
Studies have shown that copper can kill many types of germs on contact. According to a 2015 study published in Health Environments Research and Design Journal, some of the common germs copper has been proven to kill are:
Brand new research published in the New England Journal of Medicine found that copper can be effective against SARS-CoV-2, the virus responsible for the coronavirus pandemic. The study showed that after four hours, the virus was no longer infectious on copper’s surface. In comparison, coronavirus was still infectious on plastic surfaces after 72 hours.
The applications of antimicrobial copper
One of the main applications of copper is in hospitals, although the use is not widespread. In the same study as above, researchers determined the germiest surfaces in a hospital room – bed rails, call buttons, chair arms, tray table, data input, and IV pole – and replaced them with copper components.
The results were very promising. Compared to the rooms made with traditional materials, there was an 83% reduction in bacterial load on the surfaces in the rooms with copper components. Additionally, infection rates of patients were reduced by 58%.
Technically, you can use copper at home. However, according to Johnson, the majority of copper products for the home have a treatment on it to prevent the oxidation that causes the beautiful original color of the copper to turn to a greenish-blue over time. This treatment prevents you from getting the beneficial antimicrobial properties of copper. That being said, copper still has the ability to be toxic to bacteria when it’s at this oxidized greenish state, however, according to Johnson, scientists still don’t know exactly how this mechanism works.
According to current research, the downside of using copper is that it isn’t as effective at destroying viruses as it is at killing bacteria – particularly if it’s an airborne virus. Much of this has to do with the fact that viruses are technically not living organisms — they are infection agents, which are not “alive” like cells are, and as such they are more durable.
“Viruses are different in that they are not cells but rather infect healthy cells that allows them to replicate. The virus can come in direct contact with the upper respiratory tract and eyes and enter healthy cells, so a copper strategy would be largely ineffective [in that case],” says Bilsky.
Another downside is that there are some unsubstantiated claims that may mislead people. Some companies try to market copper jewelry or copper-infused socks as antimicrobial protection for the wearer, but these are ineffective.
Hopefully, more research will continue to be conducted so we can better understand the antimicrobial properties of copper and the most effective ways to use it in everyday life to keep us healthy.