Copper’s New Role: Germ Killer

A new study shows that replacing common hospital objects with those made of copper greatly reduces risk of infection.

We’ve already got hand sanitizer at every entrance and waiting room, signs in the bathrooms to remind us to wash our hands when we leave, and signs in the hallway reminding us to cover our mouths when we cough. What more could hospitals possibly do to cut down on infection?

Replace all that stainless steel with copper.

A recent study, led by Dr. Michael Schmidt of the Medical University of South Carolina, did just that. In intensive care unit rooms, objects near patients such as bed rails, meal tray tables, IV stands, and nurse call buttons were replaced with ones made of antimicrobial copper. Followup assessments showed a 97 percent decrease in the amount of bacteria and a 41 percent decrease in the rate of hospital-acquired infections (HAIs). The researchers presented the findings in late October at the conference of the Infectious Diseases Society of America in Boston, and will be submitting the study results to the US Environmental Protection Agency for review.

Hospitals can use all the help they can get. So populated with contagions and people with compromised immune systems, one almost has to wonder sometimes if a trip to the hospital is worth the risk. According to the Centers for Disease Control and Prevention, about one out of every 20 patients will contract an infection related to their care at the hospital. The number’s even higher for Intensive Care Units where 30 percent of patients get an infection. And the infections can be quite deadly as one in 20 who get an infection die as a result. The so-called hospital-acquired infections (HAIs) are the fourth leading cause of death in the United States, after heart disease, strokes, and cancer. Each year in the US 2,000,000 people contract HAIs and 100,000 die. In addition to lives, HAIs inflict an economic cost to hospitals that reaches $45 billion annually.

Copper’s effectiveness as a clinical disinfectant has been known for some time. In labs, copper kills 99.9 percent of bacteria within two hours, including bad bugs such as S. aureus, Pseudomonas aeurginosa, E. coli and its cousin Enterobacter aerogenes. It also kills methicillin-resistant S. aureas (MRSA) which accounts for a large proportion of hospital-acquired infections. Think you’ll be okay if you just douse up on the hand sanitizer even more?  A recent warning from the FDA will put an end to that nonsense. Despite claims to the contrary by hand sanitizer companies, the antiseptic gels do not prevent infection from MRSA. Letters were sent out from the FDA to several companies, saying they had 15 days to change the claims on their products.

Not only do you like the powerful bronze sheen, you feel good about making your kitchen cleaner, healthier.

The germ killing power that copper has shown in labs prompted US regulators to clear the sale of copper alloys for antimicrobial use back in 2008. But until very recently, however, most studies were limited to labs. Human trials remain scarce, and the current study is one of the first to show that copper is effective as a “passive infection control,” that is, a disinfectant that doesn’t require any special actions by the hospital staff or their patients. However, we should see a lot of data in the near future. Right now clinical trials to test copper’s ability to reduce bacterial transmission in clinical settings are underway in the US, the UK, Japan, Germany, and Chile.

So, is “antimicrobial copper” any different from the copper found in our pennies and our pipes, and how exactly is it able to kill bacteria? The answer to the first question is no. There’s nothing chemically different about the copper that is in the IV post, except that now you can buy copper in the shape of an IV post – you wouldn’t call the copper in your pocket antimicrobial, although I suppose you wouldn’t be incorrect to do so (I’m guessing you still shouldn’t put coins into your mouth). And just as your pennies aren’t pure copper, the antimicrobial equipment currently being tested in hospitals are copper alloys, as pure copper is soft.

The answer to the second question isn’t as straightforward. The Wall Street Journal paraphrased “Mr.” Schmidt as explaining it this way: “All living things generate electricity, and when bacteria come in contact with a copper surface, the metal siphons off their electrons, leaving them without energy.”

I’m sure kryptonite works the same.

The website,, offers more detail. Aside from keeping the good stuff in and the bad stuff out, cells need to keep a voltage difference across their membrane. Put another way, cells – not just bacteria but neurons, skin cells, all cells in fact – are charged. Copper is one of the more conductive elements, so when bacteria come in contact with it, their all important charge dissipates and the membrane ruptures. With the innards of the cell exposed, copper ions stream into the cell to wreak havoc on the enzymes that make the bacterium’s metabolism go.

At least, this is the best guess at the moment. Because copper works so fast it has been a challenge for researchers to get that telltale microscopic snapshot. But scientific curiosity about copper’s antimicrobial effects will become less essential if the upcoming human trials show the benefits of the current one. At a time when vitamins and minerals and other daily supplements seem to be letting us down, it’s nice to see copper casting itself into this new role of hospital sanitizer, and life saver.

[image credits: CopperForHealthCare and Mountains Edge Copper Art]
image 1: copper cart
image 2: overbed table
image 3: counter

Peter Murray
Peter Murray
Peter Murray was born in Boston in 1973. He earned a PhD in neuroscience at the University of Maryland, Baltimore studying gene expression in the neocortex. Following his dissertation work he spent three years as a post-doctoral fellow at the same university studying brain mechanisms of pain and motor control. He completed a collection of short stories in 2010 and has been writing for Singularity Hub since March 2011.
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