Project Origins and Public Health Significance

Rediscovery of antimicrobial copper. The antimicrobial copper project was conceived and initiated by Harold Michels, PhD of the United States Copper Development Association Inc.(CDA).  The idea germinated after reading a publication** authored by a nurses study carried out in a hospital in Erie Pennsylvania that compared the level of E. coli  contamination on hospital doorknobs.  The study found high levels of the bacteria on stainless steel and aluminum doorknobs but low levels on doorknobs made of brass, a zinc-containing copper alloy. 


In order to determine whether the copper in the brass was responsible for killing the bacteria,* a series of tests were conducted on two dozen different copper alloys covering a broad range of compositions in the laboratories of  C.W. Keevil, PhD of the University of Southhampton, in United Kingdom.  A concentrated sample of E. coli was exposed to a small sheet of each of the copper alloys and the number of surviving bacteria monitored over time.  All two dozen alloys exhibited a significant reduction in the number of surviving E. coli. but to varying degrees.  The greater the concentration of copper in the alloy the greater the killing.  Stainless steel, which served as the experimental control, showed no meaningful reduction.  Over the next few years, many other species of bacteria were tested on a variety of copper alloy surfaces.  In addition fungi were challenged by copper and generally showed a strong reduction.  Viruses were also tested, and found to be inactivated, meaning that they can no longer cause infections.


Regulatory approval.  The next phase in the project was regulatory approval, which was legally required in the U.S. because something alive, in this case disease-causing bacteria* were being killed.  Six types of disease-causing bacteria were tested under three EPA approved  protocols in an EPA approved and audited independent third-party laboratory.  This resulted in ground-breaking event, the Public Health registration of copper alloys as antimicrobial materials.  Funding for both the laboratory and regulatory testing, that was briefly described above, was provided by the members of the Copper Development Association in the United States (CDA-US) and the International Copper Association (ICA). 

Clinical testing.  The next phase was a clinical trial.  This clinical trial was designed to answer the following questions:  

  • Could the presence of copper alloys in a hospital environment decrease the levels of infection-causing microbes? 

  • Does a decreased in the number of bacteria translate into a reduction in hospital acquired infections? 


A clinical trial was conducted in the medical intensive care units (medical ICUs) of three hospitals: the Medical University of South Carolina (MUSC), the Memorial Sloan-Kettering Cancer Center (MSKCC) and the Ralph H. Johnson Veterans Affairs Medical Center (RHJVA).  Key individuals involved in each hospital included: C.D. Salgado, MD (MUSC), M.J Schmidt, PhD (MUSC), who also served a the microbiologist for this trial in all three hospitals, K.A. Sepkowitz, MD (MSKCC) and J.F. John, MD(RHJVA). 


Six copper component were placed in random medical ICU rooms.  Both bacterial contamination and infection rates were tracked over a 2 year period (750+ patient nights).  The findings demonstrated an over an 80% reduction in live bacteria on the copper surfaces and a 58% reduction in infection rates among the patients treated in the copper-containing medical ICUs.  The clinical trial was very carefully designed and executed and the results were shown to be statistically significant at the highest level (P = 0.013).  This was the very first time that an antimicrobial surface was shown to reduce infections.   The results of this clinical study were published in a peer reviewed journal.*** (Note: infection reduction is being mentioned only for educational purposes.)  All those involved are very grateful that the US Army Materiel Command, US Department of Defense funded this pioneering clinical trial. 

Although these results are very positive and highly statistically significant, infection reduction claims cannot be made in advertisements because EPA approval has not been granted.  The EPA requires similar results in additional clinical trials before it will consider infection reduction claims.  Unfortunately, an additional source of funding for a second clinical has not been identified.

After more than 15 years of sustained investment to develop the scientific evidence base, secure regulatory approvals, stimulate product development and raise awareness, industry trade associations have transferred further market development responsibilities to the supply chain.  This website was created to fill that void for the sole purpose of advocating for the deployment of antimicrobial copper in the fight against bacteria that cause infections.

 **P.J. Kuhn, Doorknobs: A source of nosocomial infections?, Diagnostic Medicine, 62-63, 1983

***C.D. Salgado, et. al., Copper Surfaces Reduce the Rate of Healthcare Acquired Infections in the Intensive Care Unit, ICHE,  34: 479-486, 2013