Antibacterial properties of copper

Did you know that the metal Copper has antimicrobial properties? I came across an article a couple of years back when Methicillin Resistant Staphylococcus Aureus (MRSA) was in all the headlines. I was amazed at how effective this metal is and wondered why I hadn't heard more about it. As you can see by the graph below MRSA cannot live more than one and half hours on the metal. Copper alloys e.g. bronze and bronze (bronze containing more copper) with lesser amounts of copper also have antimicrobial properties but are not as efficient and need longer contact times to be effective. Stainless steel has no effect on MRSA nor any other infectious microbe.

Graph depicts survival times of Methicillin Resistant Staphylococcus aureus on three copper alloys and stainless steel (C304) at room temperature. C19700 (99% copper) limited survival to 1.5 hours. C24000 (80% copper) showed a significant reduction after 3 hours and complete inviability after 4.5 hours. C77000 (55% copper) showed significant and continuing reduction after 4.5 hours. Survival time on stainless steel continued up to 72 hours.

Wikipedia offers the following information on the effectiveness of copper:

E. coli
The bacterium produces potent toxins that cause diarrhea, severe aches and nausea in infected persons. Recent studies have shown that copper alloy surfaces kill E. coli O157:H7. Over 99.9% of E. coli microbes are killed after just 1–2 hours on copper. On stainless steel surfaces, the microbes can survive for weeks.
MRSA
Methicillin-resistant Staphylococcus aureus (MRSA) is a dangerous bacteria strain because it is resistant to beta-lactam antibiotics. In 2008, after evaluating a wide body of research mandated specifically by the United States Environmental Protection Agency (EPA), registration approvals were granted by EPA in 2008 granting that copper alloys kill more than 99.9% of MRSA within two hours.
Clostridium difficile
Clostridium difficile, an anaerobic bacterium, is a major cause of potentially life-threatening disease, including nosocomial diarrheal infections, especially in developed countries. C. difficile endospores can survive for up to five months on surfaces. The pathogen is frequently transmitted by the hands of healthcare workers in hospital environments. C. difficile rivals MRSA as the most common organism to cause hospital acquired infections in the US
The antimicrobial efficacy of various copper alloys against Clostridium difficile was recently evaluated. The viability of C. difficile spores and vegetative cells were studied on copper alloys C11000 (99.9% copper), C51000 (95% copper), C70600 (90% copper), C26000 (70% copper), and C75200 (65% copper). Stainless steel (S30400) was used as the experimental control. The copper alloys significantly reduced the viability of both C. difficile spores and vegetative cells. On C75200, near total kill was observed after one hour. On C11000, near total kill was observed after 3 hours. On C70600, near total kill was observed after 5 hours. On C26000, near total kill was achieved after 48 hours. On stainless steel, no reductions in viable organisms were observed after 72 hours (3 days) of exposure and no significant reduction was observed within 168 hours (1 week).
Influenza A
Influenza, commonly known as flu, is an infectious disease from a viral pathogen different from the one that produces the common cold.
After incubation for one hour on copper, active influenza A virus particles were reduced by 75%.  After six hours, the particles were reduced on copper by 99.999%. Influenza A virus was found to survive in large numbers on stainless steel.


As you can see by the quotes above copper is a very effective antimicrobial.  So how can this help the athletic trainer?  We need to examine any frequently touched surface that have a copper or copper alloy version.  This could include doorknobs, light switch plates, faucets, pens, or countertops.  


The idea of a copper countertop peaked my interest since it is a large, frequently touched area that is a reservoir for microbes. Being that copper counter tops are expensive I decided to look into making one myself.  I have a 20 foot long counter in one of our facilities.  After searching the internet I came across Storm Copper. They specialize in a variety of copper products and I settled on copper roofing flashing. I order a 24" by 25' roll which arrived rolled up in a wooden crate.  I unrolled it  and placed weights on it so that it would take a more flattened shape.  I then sanded the old formica countertop to roughen up the surface.  I attached the sheet using an adhesive like liquid nails, used a rubber mallet to bend over the edges and tacked and glued the edges down.  It wasn't the most professional job, but it turned out okay. Certainly no one has stated that it is hideous.  I feel the benefits outweighed the aesthetics. 


The price of metals has increased drastically the last few years, a less expensive alternative would be the 0.10" (30 Gauge).  There are various widths and lengths to choose from. 


The copper will tarnish with time especially when in contact with certain chemicals like tape remover.  A good metal polish will bring it back to its original shine.  Below is a picture of a section of my counter.  It is nice to know that every couple of hours this counter is disinfected without any effort at all.