What is meant by 'antimicrobial'?
'Antimicrobial' is the ability of a substance to kill or inactivate microbes, such as bacteria, fungi (including moulds) and viruses.
Which microbial pathogens can copper inactivate?
The scientific literature cites the efficacy of copper to inactivate many different types of harmful bacteria, fungi and viruses, including:
Carbapenem-resistant Enterobacteriaceae (CRE)
Clostridium difficile (including spores)
Coronavirus (Human 229E)
Enterobacter aerogenesEscherichia coli O157:H7Helicobacter py
Influenza A (H1N1)
Norovirus or Norwalk-like virus
Staphylococcus aureus (MRSA, E-MRSA and MSSA)
Vancomycin-resistant enterococcus (VRE)
Is copper effective against the novel coronavirus (COVID-19)?
A New England Journal of Medicine article authored by van Doremalen et al. reported that Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the newly emerged strain of coronavirus that causes COVID-19 infections, retains infectivity in aerosols and on a variety of common surfaces for extended periods of time. Most significantly, while the virus remained infective on plastic and 304 stainless steel for up to 48-72 hours, inactivation was observed in 4 hours on a 99.9% copper alloy.
Another coronavirus, Human Coronavirus 229E (Hu-CoV-229E) causes a broad spectrum of lung disorders. An article published in 2015 authored by Warnes et al.3 showed that Hu-CoV-229E remained infectious following exposure to polytetrafluoroethylene (PTFE or Teflon), polyvinyl chloride (PVC), ceramic tile, glass, silicone rubber, and stainless steel, but was rapidly inactivated on copper and on a range of copper-zinc and copper-nickel alloys. Complete loss of infectious activity was reached after as little as a 5-minute exposure, depending on the particular alloy tested. Not only was the inactivation rapid but it was accompanied by the irreversible destruction of viral RNA and massive structural damages.
van Doremalen, N. T. et al., 2020. Aerosol and surface stability of SARS-CoV-2 as compared with SARS-CoV-1. N. Engl. Jour. Med. DOI: 10.1056/NEJMc2004973
Warnes, S.L., Z.R. Little, C.W. Keevil, 2015. Human coronavirus 229E remains infectious on common touch surface materials. mBio 6:e01697-15.
What does the EPA registration mean?
Registration of copper and certain copper alloys such as brass and bronze means that the EPA recognises these solid materials' antimicrobial properties. Products made from any of the registered alloys are legally permitted to make public health claims in the US.
Where can copper be used?
In addition to antimicrobial copper for frequently touched surfaces in hospitals, those materials may be used in other settings where transmission of infection could occur, such as care homes, ambulances, gyms, schools, public buildings, public transport, cruise ships and offices.
How is copper superior to other antimicrobial surfaces?
Copper and copper alloy products are antimicrobial through and through. Even when surfaces made of these materials are scratched, their antimicrobial efficacy continues to work - they won't wear away like coatings or other treatments can. Copper alloys are the only solid metals with an EPA public health product registration.
If microbes die on copper, is it safe?
Yes, antimicrobial copper surfaces are safe and long lasting. The copper industry initiated a Voluntary Risk Assessment for copper. The assessment process was agreed with the Italian Government's Istituto Superiore di Sanità, acting as the review country on behalf of the European Commission and the EU Member States. The risk assessment has now been completed and one of the main conclusions, accepted by the European Commission and EU Member State experts, is 'the use of copper products is in general safe for Europe's environment and the health of its citizens.'
Copper is also an essential micronutrient in the human diet, along with zinc and iron. An adult needs 1mg of copper every day. Foods rich in copper include chocolate, nuts and seeds. A balanced diet should provide enough copper to avoid a copper deficiency.