Science Matters →

Too Much Copper Is Fatal To Germs

scientist filling viles
Rachel Salvatori, Curon senior laboratory technician, prepares solutions for copper analysis. Photo courtesy: Cupron Inc.

For thousands of years, people noticed that copper helped ward off certain illnesses, but no one knew why. It seemed that copper had magical powers. In the 19th century, scientists put forth the germ theory, which held that tiny organisms invisible to the human eye were responsible for many diseases. As germ theory gained acceptance, it was recognized that copper had the power to kill germs.

Vikram Kanmukhla

The reason copper is antimicrobial is complicated, but chemist Vikram Kanmukhla offered a simple explanation. “All living organisms require copper to live,” said, Kanmukhla, Director of Material Services for Cupron Inc., a Henrico-based company. Humans need copper in their diets, and microorganisms also need a tiny amount, he said. If germs such as bacteria, viruses and fungi contact large amounts of copper, they overdose, the cell walls rupture, and the organisms die.

That is the basis of Cupron’s business, which uses copper-based antimicrobial technology for healthcare, consumer and military applications. Cupron, for example, embeds copper compounds, such as copper oxide, into the molecules of fibers that are woven into cloth. Since copper becomes an integral part of the cloth, it won’t wash or wear off, as happens with garments sprayed with a copper solution or other antimicrobal treatments, Kanmukhla said. 

Cupron’s patented technology also is used in making solid surfaces, such as countertops and sinks, especially for hospitals. “Healthcare is our main focus right now,” he noted. 

Sharon Oakley

One study at a Norfolk-area hospital showed a 28 percent reduction in the infection rate using copper-infused bed linens, patient gowns and countertops, according to Sharon Oakley, Cupron’s Director of Marketing Technology. More studies are under way.

Oakley explained that, with  an infection like MRSA, which can easily move throughout a hospital, it is important to keep the infection from spreading. MRSA is caused by a type of bacterium that becomes resistant to the antibiotics used to treat it. Germs need copper so they can’t avoid taking it in. This means they don’t become resistant to copper-infused material, as often happens with common antibacterial and antiviral medicines.  “A patient who contracts MRSA sheds the microorganisms into the environment,” Oakley said. For this reason, copper-infused bed linens and patient gowns can be the first line of defense to keep infection under control.

Copper-infused bed linens feel like regular blankets and sheets, are just as durable and can be laundered like regular bed linens. “The cost of these bed linens is usually no more than 15 to 20 percent higher  than regular linens,” Oakley said. “There are no reports of adverse effects to people” resulting from contact with items infused with copper, she added.


Using a technology different than that used by Cupron, copper is mixed with other metals to kill germs in some hospitals and other public places, such as public restrooms. Hartsfield International Airport in Atlanta has installed water fountains, made of a copper and nickel alloy, in its terminal buildings.

Gold and silver also have antimicrobial properties, Oakley said. The cost of gold often makes its use prohibitive as a germ fighter. Although silver has certain medical uses, it is significantly more expensive than copper.

Oakley often is asked about the effectiveness of copper bracelets that are sold to ease arthritis pain.

“There is an unfortunate proliferation of health claims made about copper bracelets,” Oakley said. “There is no scientific evidence to back up such claims,” she added.

“Some samples we have tested in our lab don’t even contain copper,” Oakley said.