Copper kills germs, a fact ancient Egyptians — who used it to sterilize drinking water and wounds — knew.
That fact slipped into obscurity until a member of the Copper Development Association started asking questions.
Harold Michels, senior vice president of technology and technical services for the CDA, found an old scientific paper that hinted at copper’s possible anti-microbial properties.
To find out if the metal and its alloys, brass and bronze, are able to kill potentially deadly bacteria on contact, he conducted a controlled laboratory experiment in 2000.
He asked the CDA, a membership organization of the copper industry based in New York City, to conduct further research and testing to explore copper’s ability to kill bacteria, particularly in hospitals and other health care facilities where infection is a problem.
In late February, the U.S. Environmental Protection Agency approved the registration of copper with the public health claim of killing bacteria.
“This is the first material allowed under this registration,” says Mr. Michels, who holds a doctorate in materials science and is a professional engineer licensed in New York and California.
Using copper, though, is a passive method, not a substitute for standard cleanliness practices, he says.
“Anything that the patient or health care worker touches we’re going to try to cover with metallic copper to try to break the cycle of infection,” says Michael Schmidt, professor and vice chairman of the department of microbiology and immunology at the Medical University of South Carolina (MUSC) in Charleston, S.C. He holds a doctorate in microbiology.
The CDA tested five strains of bacteria — including Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli), on various copper, brass and bronze samples over a period of year, Mr. Michels says. The tests showed that copper killed more than 99.9 percent of bacteria within two hours of exposure, he says.
“They’re alive for 45 minutes to 1.5 hours, then they all die,” Mr. Michels says. “We don’t know why that happens. At this point, it’s truly speculation.”
The tests used tens of millions of bacteria, while the most highly contaminated surface the CDA identified had 20,000 bacteria, Mr. Michels says. A copper surface can kill fewer bacteria at a faster rate, but until the bacteria are killed, they can be picked up and passed around, he says, adding that good hygienic practices help reduce this likelihood.
The CDA plans to conduct clinical trials at three hospitals: MUSC, the Ralph H. Johnson Veterans Affairs Medical Center, also in Charleston, and the Memorial Sloan-Kettering Cancer Center in New York City.
Rooms in the hospitals’ intensive care units will have specially made copper surfaces that can be compared to existing plastic and Formica surfaces in designated control rooms. These surfaces include counters, the hardware on doors and furniture, bed rails, intravenous stands and nurse call buttons.
“It’s a fascinating concept that our common surfaces that we assume to be clean in fact often are contaminated,” says Dr. Joseph F. John Jr., associate chief of staff for education and staff physician at the Ralph H. Johnson VA Medical Center. “That very contamination does submit patients to exposure to multi-resistant bacteria,” he says.
The clinical trials, funded by the Department of Defense, will be conducted in three phases. The first phase is completed and identified the number of bacteria present in hospital rooms to establish base-line data.
The second phase, which is scheduled to begin this month, will compare bacteria in rooms with and without copper, followed by the last phase to determine if bacteria on patients is the same as that on touch surfaces, Mr. Schmidt says.
Once the studies are concluded, the CDA plans to educate health care providers about using copper in patients’ rooms, including those in the metropolitan area.
“The principal thing is you’re going to have to change people’s attitudes,” Mr. Schmidt says. “Green is the new clean, not stainless steel. As copper is developing that beautiful patina, it’s indicating to you that it’s killing bacteria.”
Although copper is costly, Mr. Schmidt expects that the financial handlers at health care facilities will see a return on investment from reduced spending on hospital-acquired infections, he says. There is a 1 in 20 chance of getting such an infection during a hospital stay, he says.
The market for copper can be taken beyond the health care industry to nursing homes, food processing plants and equipment, and pharmaceutical production companies, says Brian O’Shaughnessy, chairman of Revere Copper Products, a manufacturing company in Rome, N.Y. He is chairman of the CDA.
“It’s not just for hospitals. It’s for use in any environment in which one is trying to control the transmission infectious pathogens,” Mr. O’Shaughnessy says.
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