In an experiment with aerosolized SARS-CoV-2 and SARS-CoV-1, at 21-23 degrees C and 40% humidity, both reached undetectable levels within 8 hours exposure to copper; by contrast, they lasted 72 hours on stainless steel and plastic.[1]
H1N1 influenza, which was another pandemic virus, though not a coronavirus, lasted significantly less time on copper than stainless steel; 10^5 viable viruses after 24 hours on stainless steel vs. 10^2 viable viruses after 2 hours on copper.[2]
Human coronavirus 229E remains infectious on plastic, ceramic, glass, and stainless steel for at least 5 days, was inactivated in less than 5 minutes on copper and brass when applied dry, and inactivated in less than an hour when applied in solution to metal alloys containing >75% copper.[4]
Using copper-coated surfaces in real-world environments reduces microbial contamination. In 5 residential healthcare facilities, where half of the doorknobs and handrails were coated with copper alloys while half were not, the bacterial concentration was significantly (p < 0.0001) lower on the copper-coated doorknobs and handrails.[5] Similarly, when weights and grips in a gym were coated with copper alloy or left as rubber or stainless steel, the bacterial concentrations on the copper-coated surfaces were 94% lower than the controls.[6]
Sarah Constantin’s overview: https://srconstantin.github.io/2020/03/31/disinfectants.html
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