Brief History
Heavy metal such as silver, copper and even mercury have been used for centuries as a natural disinfectant because of their biocidal property known as the oligodynamic effect . Historically, heavy metals have been stuffed into wounds to prevent infection, used as topical treatments to rid existing infection, and crafted into surgical tools and bandages. While many of these archaic treatments were once medical breakthroughs, most heavy metals are toxic or carcinogenic to humans.
Affected Microbes
Viruses
Bacteria (AMR)
Fungi
Endospores
Summary
Antimicrobial copper and silver are some of the few heavy metals that have no significant adverse effects on humans with external interaction making copper plating a safe alternative to stainless steel. Due to their germicidal properties, these two metals are used to coat surfaces and utensils. Unfortunately, silver is a valuable and expensive metal so it is typically reserved for medical procedures. Copper on the other hand, can be used to coat commonly touched surfaces such as door handles, prep-tables, and bathroom fixtures. The antimicrobial properties of metallic copper and copper alloys are very effective at contact killing. Copper was officially recognized as the first solid antimicrobial material in 2008 by the Environmental Protection Agency (EPA).
How does Antimicrobial Copper Work?
The exact mechanism behind the oligodynamic effect is not completely understood, however researchers have several ongoing theories:
1) The cell membrane ruptures or cell wall is damaged eventually leading to cell death
2) Copper ions cause oxidative stress which is toxic and damaging to the cell
3) Genetic material becomes damaged leading to the deactivation of pathogenic or reproductive properties
Antimicrobial copper works most effectively in heated conditions, high humidity, and when higher concentrations of copper are present in alloys. Copper’s effect on specific organisms varies widely. Some microbes like bacteria can be deactivated within minutes and 99.9% of all bacteria is killed within two hours, whereas stubborn endospores may take up to a day.
Concerns
Antimicrobial copper is effective at deactivating bacteria with antibiotic resistance that most disinfectants and medications fail to accomplish. The biggest concern with wide use of copper surfaces is copper resistance. Bacteria have evolved several methods to protect themselves against copper ions. The exact mechanisms of this type of resistance is complicated, but some strategies involve extracellular sequestration of copper ions, stronger impermeability of the cell membrane, and active removal of copper ions.
Current research suggests that copper does not lose its antimicrobial properties over time or with extensive usage, however not many long-term studies have not been conducted.
Sustainability
Copper plating does not lose its functionality so it does not need to be replaced unless damaged. The cost of copper is roughly $0.18 per ounce or $2.93 per pound. For reference, silver runs about $0.85 per gram and $26.58 per ounce. Copper plating typically uses copper-alloys as opposed to pure metalic copper, which reducing the cost. A role of pure copper foil (0.1 x 100 x 1000MM 39") runs about $10 online, whereas the cost for fitting an entire building would vary drastically based on size, type of copper coating, and copper concentrations.
Learn more about Cuverro: A Copper Surfaces Company