Scientists at the University of Southampton, U.K., have found that E. coli O157:H7, a harmful bacterium primarily associated with raw and undercooked ground beef or foods that come into contact with raw meat, cannot survive on certain copper alloy surfaces. The study, published in the June 2006 issue of Applied and Environmental Microbiology, compares the ability of copper alloys to eradicate E. coli with that of stainless steel, which is commonly used for food processing surfaces.
The results were significant. While stainless steel had no effect on the viability of the E. coli at room temperature, three copper casting alloys effectively eliminated it, and two others significantly reduced it. The bacteria sample tested on silicon bronze (95% copper) were significantly reduced in 45 minutes and completely eradicated in 75 minutes. Brass (85% copper) and red brass (93% copper) killed the bacteria in 3.0 hours and 4.5 hours, respectively. Significant reductions were noted after six hours on Ni- Al bronze (81% copper) and yellow brass (61% copper).