Eight hours. It takes a piece of brass approximately eight hours to disinfect itself naturally.
Brass is an alloy of copper and zinc that naturally disinfects itself. The copper in the brass makes the alloy germicidal, which means that it is capable of destroying microbes that grow upon its non-living surface. Copper is effective against Staphylococcus aureus (more commonly known as the hospital ward bothering MRSA), which is usually methicillin-resistant, and other pathogens such as Escherichia oil.
This is due to the oligodynamic effect, first discovered by the Swiss botanist Karl Wilhelm von Nageli in 1893, which allows certain metals - especially heavy metals - to self-sanitize. Although the exact mechanism is unknown, it is thought this is because the ions of the metals denature enzymes of the cells or organisms found upon their surfaces by binding to reactive groups, resulting in their inactivation and precipitation. This explanation has been gleaned from data recovered from experiments on silver. Silver disinfects itself ever more quickly than copper.
Due to their wide use by a wide ranger of people over the course of any given day, door knobs made from non-disinfectant materials such as aluminum or stainless steel are veritable breeding grounds for infections. As such, unvarnished brass door knobs are used widely in buildings where viruses and infections need to be kept to a minimum, such as hospitals, although they are highly useful in any buildings.
Brass is an alloy of copper and zinc that naturally disinfects itself. The copper in the brass makes the alloy germicidal, which means that it is capable of destroying microbes that grow upon its non-living surface. Copper is effective against Staphylococcus aureus (more commonly known as the hospital ward bothering MRSA), which is usually methicillin-resistant, and other pathogens such as Escherichia oil.
This is due to the oligodynamic effect, first discovered by the Swiss botanist Karl Wilhelm von Nageli in 1893, which allows certain metals - especially heavy metals - to self-sanitize. Although the exact mechanism is unknown, it is thought this is because the ions of the metals denature enzymes of the cells or organisms found upon their surfaces by binding to reactive groups, resulting in their inactivation and precipitation. This explanation has been gleaned from data recovered from experiments on silver. Silver disinfects itself ever more quickly than copper.
Due to their wide use by a wide ranger of people over the course of any given day, door knobs made from non-disinfectant materials such as aluminum or stainless steel are veritable breeding grounds for infections. As such, unvarnished brass door knobs are used widely in buildings where viruses and infections need to be kept to a minimum, such as hospitals, although they are highly useful in any buildings.
