The Science behind Antimicrobial Copper.
The mechanism by which Antimicrobial Copper kills bacteria is a complex by nature, but the effect is simple.
Science suggests that Antimicrobial Copper kills bacteria with a
multifaceted attack. The questions and answers below
summarize active and ongoing research seeking to explain how
Antimicrobial Copper is a highly effective touch surface.
How does copper affect bacteria?
Science suggests that copper surfaces affect bacteria in two
sequential steps: the first step is a direct interaction between
the surface and the bacterial outer membrane, causing the membrane
to rupture. The second is related to the holes in the outer
membrane, through which the cell loses vital nutrients and water,
causing a general weakening of the cell.
How can copper punch holes in a bacterium?
Every cell's outer membrane, including that of a single cell
organism like a bacterium, is characterized by a stable electrical
micro-current. This is often called "transmembrane potential", and
is, literally, a voltage difference between the inside and the
outside of a cell. It is strongly suspected that when a bacterium
comes in contact with a copper surface, a short circuiting of the
current in the cell membrane can occur. This weakens the membrane
and creates holes.
Another way to make a hole in a membrane is by localized
oxidation or "rusting." This happens when a single copper molecule,
or copper ion, is released from the copper surface and hits a
building block of the cell membrane (either a protein or a fatty
acid). If the "hit" occurs in the presence of oxygen, we speak of
"oxidative damage", or "rust." An analogy is rust weakening and
making holes in a piece of metal.
After punching holes, how do copper ions further damage
Now that the cells main defense (its outer envelope) has been
breached, there is an unopposed stream of copper ions entering the
cell. This puts several vital processes inside the cell in danger.
Copper literally overwhelms the inside of the cell and obstructs
cell metabolism (i.e., the biochemical reactions needed for life).
These reactions are accomplished and catalyzed by enzymes. When
excess copper binds to these enzymes, their activity grinds to a
halt. The bacterium can no longer "breathe", "eat", "digest" or
How can copper's effect be so fast, and affect such a
wide range of microorganisms?
Experts explain the speed with which bacteria perish on copper
surfaces by the multi-targeted nature of copper's effects. After
membrane perforation, copper can inhibit any given enzyme that
"stands in its way," and stop the cell from transporting or
digesting nutrients, from repairing its damaged membrane, from
breathing or multiplying.
It is also thought that this is why such a wide range of
microorganisms are susceptible to contact action by copper.
*Laboratory testing shows that, when cleaned regularly,
antimicrobial copper surfaces kill greater than 99.9% of the
following bacteria within 2 hours of exposure: MRSA, VRE,
Staphylococcus aureus, Enterobacter aerogenes, Pseudomonas
aeruginosa, and E. coli O157:H7. Antimicrobial copper surfaces
are a supplement to and not a substitute for standard infection
control practices and have been shown to reduce microbial
contamination, but do not necessarily prevent cross contamination
or infections; users must continue to follow all current infection