What is the Oligodynamic Effect?

Antimicrobial metals

It can’t be seen with the naked eye, but some metals are constantly attacking and destroying bacteria, fungi, viruses and other germs they come in contact with. This is called the oligodynamic effect – and explains how these metals can be classified as antimicrobial. Studies have shown that healthcare acquired infection rates have been reduced by up to 58 percent in hospitals fitted with oligodynamic metals (specifically copper and it’s alloys) on frequently touched surfaces like handles and rails.

With two decades of observing the oligodynamic effect, Professor of environmental healthcare at the University of Southampton, Bill Keevil has said “we’ve seen viruses just blow apart” when they land on a copper surface – beginning to die within minutes and are undetectable within hours.

The oligodynamic effect was discovered by Karl Wilhelm von Nägeli in 1893 as a toxic effect of metal ions on algae, bacteria, fungi, eukaryotic and prokaryotic microorganisms, fungi, moulds, spores and viruses.

There isn’t complete consensus of exactly what is happening, however, it is evident that the antimicrobial activity is linked to the oxidative behaviour of the metal. Recent research has begun to explain what is actually occurring at the cellular level – metals oxidise when they are able to come into contact with water, either liquid or air moisture. As this happens, electrons are pulled from the bacteria’s cell wall – just like removing bricks from an actual wall – eventually the cell wall breaks, killing the bacteria. According to University of Southampton’s Dr Sarah Warnes, “Exposure to copper damages the bacterial respiration and DNA, resulting in irreversible cell breakdown and death.”

Although the mechanisms are yet to be completely understood, it is obvious how useful the oligodynamic effect of metals, and specifically copper, can be in minimising the spread of infection and viruses, leading people to wonder why it’s not used more frequently.