Antimicrobial Copper

 

By
Gerard Hillenbrand, P.E.

ANTIMICROBIAL COPPER

That was the intriguing subject of Met Section’s May 21, 2009 Technical Dinner Meeting at Con Edison Headquarters in Manhattan. The official title of the presentation was “Copper Alloys, the killer of Hospital Superbugs”, and the featured speaker was a distinguished member of the Met Section, Harold Michels, Senior Vice-President of the Copper Development Association. Professional Engineers attending this technical lecture qualified for one development hour of credit toward satisfying the continuing education requirements mandated several years ago by the NY State Education Department.

Dr. Michels is a Mechanical Engineering Graduate of CCNY and a graduate of Masters and Doctoral studies in Material Science at NYU. He is a licensed Professional Engineer in New York and California. Dr. Michels worked for 28 years with Inco, Limited, a major nickel and copper producer, where he specialized in corrosion, marine testing and strategic planning. In 1999 he joined the Copper Development Association where he directs the program for research and development for the antimicrobial effectiveness of Copper Alloys, and the efforts to conduct clinical trials concerning Copper Alloys with the Environmental Protection agency and the Department of Defense he has also co-authored several technical papers on the effects of Copper Alloys on Bacterial and other Pathogens.

Copper is a non-ferrous metal with the following characteristics: Chemical Symbol = Cu, Atomic Number 29, Atomic Weight – 63.54, Density = 0.321lbs/in3, Melting Point = 1981.4oF. The metal copper and its alloys are widely used because of their high thermal and electrical conductivity, good corrosion resistance, ease of workability, and its unique ability to form alloys with other elements. The widespread use of copper dates back to the ancient world where the metal was used or its medicinal properties, such as a healing of wounds, a cure for infections skin conditions, and as an additive for water purification, and such esoteric problems as sore throats and intestinal diseases. In the nineteenth century the French scientist Louis Pasteur used copper compounds to create immunity to a local Cholera Epidemic, as well as treatments for infections inside the human body. In the modern era copper is used widely for Anti-Corrosion properties. For example, a sailboat was built in Holland with a copper hull in 1964, and this boat is in perfect sailing condition today. However, until recently, the medicinal properties of copper have been glossed over.

Dr. Michels then reported that upwards of tow million patients become infected during their hospitalizations per year. Of these, 100,000 patients pass away at an additional treatment cost of almost $30 Billion. These hospitals-acquired infections are caused by the methicillin-resistant Staphylococcus aureus (MRSA) also known as the “Hospital Superbug”. Hospital infections are far from the only problem. For example, almost 80 million illnesses caused by contaminated food occur annually in the United States Resulting in 325,000 Hospitalizations and 5000 deaths at costs of $5 Billion. Food contamination is caused by various strains of the E. Coli Bacteria, and in 2006 packaged spinach had to be recalled because of this bacteria as well as the recall in 2007 of 10 Million pounds of hamburger meat. Also consider the currently prevalent influenza epidemic which is spread by human contact such as shaking hands and sharing kisses, etc.

Recent laboratory tests show that many forms of bacteria are killed when they come in contact with dry copper and copper alloy surfaces at ordinary room temperatures. In these tests the concentrations of live bacteria on these surfaces is reduced to zero within two hours. These tests also showed that no such reduction occurs on surfaces such as stainless steel, aluminum and aluminum coatings, plastics, and painted elements. However, before copper and its alloys can be employed to reduce bacterial contamination in the United Sates, approval of this environmental protection agency (EPA) is necessary. Dr. Michels then coordinated a formal series of tests in accordance with EPA regulations, such as the Federal Insecticide, Fungicide and rodenticide act (FIFRA). These tests in a laboratory setting were successful and then the EPA authorized additional tests in hospital settings such as the Veterans Administration Hospital in South Carolina, and these tests were also successful. Dr. Michels showed the results of these tests by illustrating a series of graphs defining the reduction of contamination versus several hours of exposure. The sanitizing effects of copper and copper alloys clearly exceeded those of other material. The materials tested consisted of 99% pure copper and alloys such as brasses, bronzes, copper-nickels, phosphur bronzes, and Nickel silver. The pathogens tested were E. Coli Bacteria and the hospital superbug MRSA. Temperatures were varied from 4oC to 20oC.

Other significant test results showed that the purer the copper surface, the more effective the sanitizing effect. Copper plated surfaces were not nearly as effective as pure copper surfaces. The tarnished copper surfaces were clearly less effective than clean copper surfaces. Tests were also conducted on copper-free materials such as type S304 stainless steel, Polyethylene, and stainless steel with silver-ion coating. The copper and copper plated surfaces consistently outperformed all non-copper materials. The overall results of all these tests is that the anti-microbial response of copper and its alloys is strongly effective, long-lasting, can be continually reproduced, and provides a deadly control of human pathogens. It is clearly possible by employing copper and copper alloys to reduce or eliminate entirely the $5,000 to $15,000 per day spent to treat hospital infections.

Now that the scientific evidence has been proven, the engineering and architectural communities must take the lead in employing copper and copper alloys in hospitals, nursing homes, schools, airports, ships, public buildings, and even in private homes. Critical components include door hardware, plumbing handles, electrical control buttons, instrument control knobs, and even arms of chairs – any routinely touched surface. It is still necessary to convince hospital administrators, government healthcare officials, infectious disease medical experts, and the building construction designers. They must be made to understand that by increasing the utilization of copper and copper alloys, infectious diseases can be substantially reduced and human lives saved with a general improvement in worldwide health. If these are still skeptics and doubters just ask them to consider why almost all nations of the world utilize copper in their coinage. Th answer is that experience has shown that, in addition to corrosion prevention and high-wear properties, copper coins dramatically reduce disease transmission during financial transactions. Case Closed!

Great Work Dr. Michels and excellent lecture! The Met Section extends it sincere thanks and best wishes for future success in promoting the beneficial properties of copper.

 Posted by at 2:45 pm