Exposure to dry copper alloy surfaces, such as brass, kills a wide spectrum of microorganisms including Gram-negative and Gram-positive bacteria and fungi, and permanently inactivates several types of viruses. A large body of published evidence reports that greater than 99.9% killing occurred within a 2-hour period when the microorganism was exposed to the copper alloy samples at room temperature and typical indoor humidity levels. Included in these studies were disease-causing bacteria such as E. coli O157:H7 as well as hospital “super-bugs” such as Methicillin- Resistant Staphylococcus aureus (MRSA) and Vancomycin-Resistant Enterococci (VRE). The results of these laboratory-based tests are reviewed here. The mechanism(s) of action of copper alloy surface killing is still under investigation and progress on this important area of research will be described. It is important to note that mutations that provide resistance to copper alloy surface exposure have not been reported. These results suggest that copper alloy surfaces could be a powerful tool against the transmission of infectious disease in public settings, most particularly hospitals. In a clinical trial, summarized here, the amount of live bacteria found on components made of copper alloys was compared to that found on components made from standard materials and shown to be 83% lower. Most significantly, when infection rates were tracked in these hospital rooms with the copper components and compared to rooms containing the standard components, it was found that the infection rates were reduced by a statistically significant 58%. Thus, the widespread deployment of copper alloy components to frequently touched surfaces, such as door knobs and hand rails, has the potential to significantly reduce the rate of transmission of infections in the clinical settings and public-use spaces such as schools and transit systems.
View Full Article