Pub. 3 2013 Issue 1

14 At the Center of Utah Industry Copper Alloys C opper is a bacteriostatic material. That means copper does not harm bacteria, but bacteria cannot reproduce on its surface. As a result, copper is often used in plastics or in hospital or laboratory settings to inhibit bacteria. Compounds that include copper can also preserve wood or function as a fungicide. How effective is it? According to laboratory studies that were conducted using EPA protocols, copper applied as an antimicrobial will kill more than 99.9 percent of the following bacteria within two hours of contact if the surface is also cleaned regularly and is not cross-contaminated: • Vancomycin-resistant enterococcus, or VRE • Staphylococcus aureus; it causes staph infections • Enterobacter aerogenes, which causes skin or tissue infections • Escherichia coli O157:H7, otherwise known as E. coli • Pseudomonas aeruginosa, a source of lung infections • Methicillin-resistant staphylococcus aureus, or MRSA The EPA has a list of about 355 alloys that have been registered as being antimicrobial copper, although surfaces made with these alloys are not exempt from good, thorough, regular cleaning. Copper’s properties are not a substitute for the need to clean and disinfect surfaces. Still, just being on the EPA list is important: no alloy can be included unless it has been rigorously studied in order to verify the claims made about it. Other bacteria and alloys are currently being studied to find out howmany other additional useful applications exist. Although the EPA has approved hundreds of proven alloys, whichmeans their manufacturers can make claims about their public-health benefits, the EPA is mindful about manufacturers not claiming more benefits from the copper alloys than can be backed up by scientific research. That is almost certainly a result of its long and colorful history in medicine. The ability to kill bacteria was known anciently even though it was not understood. For example: • Egyptians sterilized water in copper drinking vessels. The Smith papyrus, written sometime around 2400 B.C., talks about using copper to sterilize both water and injuries. The Ebers papyrus, written sometimearound1500 B.C., talks about using copper to treat headaches, shaking, burns, and itching. • H i ppoc r a t es , who l i ved f r om approximately 460 B.C. to 370 B.C. in Greece, found copper useful when he was dealing with leg ulcers caused by varicose veins. Records tell us that the Greeks also mixed copper oxide and copper sulfate on wounds, and they also treated wounds with a compound made from red copper oxide and honey. • A Roman named Celsus, who may have lived at the same time as Augustus and Tiberius, wrote a medical encyclopedia in which he discussed copper and how to use it. For example, he explained how to mix copper oxide with raisin wine, saffron, and myrrh. This was his treatment for venereal disease. Another combination, copper mixed with rose oil, was supposed to be a cure for chronic ulcers. Pliny mixed black copper oxidewith honey as a treatment for intestinal worms. He also made diluted nose drops that had copper in them, eardrops to treat infection and continued on page 17 Antimicrobial