Antimicrobial Properties of Copper


With this distressing time of the COVID-19 pandemic, people are searching for ways, things, ALL WAYS and ALL THINGS that can help kill viruses and bacteria. You cannot find Clorox® disinfecting wipes to save your sole and hand sanitizer is as hard to come by as your sole being saved by Clorox® disinfecting wipes.

I have read that copper is superior to silver for its antibacterial and antimicrobial properties. This is appealing to me as I work mostly with copper. After some online research it would seem that, in clinical studies, copper does beat its metal counterparts by hours to days, even, in effectiveness of killing these germs.

This is exciting news, however, wearing a piece of copper jewelry won’t save you from getting a serious illness. Even though you need to take more precautions than simply wearing copper to be protected from infections, I still find the research fascinating on the efficacy of copper’s antimicrobial properties, in general.

How Long Does COVID-19 Live on Copper Surfaces?

A new study published in the New England Journal of Medicine found that COVID-19 remained viable in aerosols for up to 3 hours, on cardboard up to 24 hours, and on plastic and stainless steel for up to 72 hours after application to these surfaces. However, the virus remained contagious on copper for up to 4 hours; a significantly shorter time than on many other hard surfaces.

I found the following excerpt particularly interesting as it echos what most scientific websites stated about how copper kills virus germs, only in terms that are a bit more relatable.

By Ashley Laderer Mar 25, 2020 ~ For the full article read:

Copper has antimicrobial properties, meaning it can kill microorganisms like bacteria and viruses. However, the microorganism has to come in contact with the copper in order for it to be killed. This is referred to as “contact killing.”

According to Edward Bilsky, Ph.D., Provost and Chief Academic Officer at Pacific Northwest University of Health Sciences, copper can kill germs in a few ways:

  • It disrupts bacterial cell membranes — copper ions damage cell membranes or “envelopes” and can destroy the DNA or RNA of the microbe
  • It generates oxidative stress on bacterial cells and creates hydrogen peroxide that can kill the cell
  • It interferes with proteins that operate important functions that keep bacterial cells alive

The exact mechanism of how copper interferes with proteins in bacterial cells is not fully understood yet, but the current hypothesis is mis-metalation, thanks to the fact that copper is a stable metal.

“Mis-metalation is the ability of a metal to basically replace another metal,” says Michael D. L. Johnson, Ph.D., Assistant Professor of Immunobiology at the University of Arizona College of Medicine in Tucson. “Copper can just replace some of the other metals that are present in some of these other proteins [in bacteria] and by doing so, it blocks the function of those proteins.”

When you block a protein’s function, it starts a bacteria-killing chain reaction. “By blocking the function of the protein, you block the function of the pathway. When you block the function of the pathway, you block the function of the organism, and then the organism is just dead in the water,” says Johnson.

Wikipedia offers the following information about copper’s antimicrobial properties.

Antimicrobial efficacy of copper alloy touch surfaces

Copper alloy surfaces have intrinsic properties to destroy a wide range of microorganisms. In the interest of protecting public health, especially in healthcare environments with their susceptible patient populations, an abundance of peer-reviewed antimicrobial efficacy studies have been conducted in the past 10 years regarding copper’s efficacy to destroy E. coli O157:H7, methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus, Clostridium difficile, influenza A virus, adenovirus, and fungi.[25] Stainless steel was also investigated because it is an important surface material in today’s healthcare environments. The studies cited here, plus others directed by the United States Environmental Protection Agency, resulted in the 2008 registration of 274 different copper alloys as certified antimicrobial materials that have public health benefits.

E. coli

E. coli O157:H7 is a potent, highly infectious, ACDP (Advisory Committee on Dangerous Pathogens, UK) Hazard Group 3 foodborne and waterborne pathogen. The bacterium produces potent toxins that cause diarrhea, severe aches and nausea in infected persons. Symptoms of severe infections include hemolytic colitis (bloody diarrhea), hemolytic uremic syndrome (kidney disease), and death. E. coli O157:H7 has become a serious public health threat because of its increased incidence and because children up to 14 years of age, the elderly, and immunocompromised individuals are at risk of incurring the most severe symptoms.

Efficacy on copper surfaces

Recent studies have shown that copper alloy surfaces kill E. coli O157:H7.[26][27] Over 99.9% of E. coli microbes are killed after just 1–2 hours on copper. On stainless steel surfaces, the microbes can survive for weeks.

Results of E. coli O157:H7 destruction on an alloy containing 99.9% copper (C11000) demonstrate that this pathogen is rapidly and almost completely killed (over 99.9% kill rate) within ninety minutes at room temperature (20 °C).[28] At chill temperatures (4 °C), over 99.9% of E. coli O157:H7 are killed within 270 minutes. E. coli O157:H7 destruction on several copper alloys containing 99%–100% copper (including C10200, C11000, C18080, and C19700) at room temperature begins within minutes.[27] At chilled temperatures, the inactivation process takes about an hour longer. No significant reduction in the amount of viable E. coli O157:H7 occurs on stainless steel after 270 minutes.

Studies have been conducted to examine the E. coli O157:H7 bactericidal efficacies on 25 different copper alloys to identify those alloys that provide the best combination of antimicrobial activity, corrosion/oxidation resistance, and fabrication properties.[27][29][30] Copper’s antibacterial effect was found to be intrinsic in all of the copper alloys tested. As in previous studies,[31][32] no antibacterial properties were observed on stainless steel (UNS S30400). Also, in confirmation with earlier studies[31][32] the rate of drop-off of E. coli O157:H7 on the copper alloys is faster at room temperature than at chill temperature.

For the most part, the bacterial kill rate of copper alloys increased with increasing copper content of the alloy.[29][30] This is further evidence of copper’s intrinsic antibacterial properties.

Efficacy on brass, bronze, copper-nickel alloys

Brasses, which were frequently used for doorknobs and push plates in decades past, also demonstrate bactericidal efficacies, but within a somewhat longer time frame than pure copper.[27] All nine brasses tested were almost completely bactericidal (over 99.9% kill rate) at 20 °C within 60–270 minutes. Many brasses were almost completely bactericidal at 4 °C within 180–360 minutes.

The rate of total microbial death on four bronzes varied from within 50–270 minutes at 20 °C, and from 180 to 270 minutes at 4 °C.

The kill rate of E. coli O157 on copper-nickel alloys increased with increasing copper content. Zero bacterial counts at room temperature were achieved after 105–360 minutes for five of the six alloys. Despite not achieving a complete kill, alloy C71500 achieved a 4-log drop within the six-hour test, representing a 99.99% reduction in the number of live organisms.

Efficacy on stainless steel

Unlike copper alloys, stainless steel (S30400) does not exhibit any degree of bactericidal properties against E. coli O157:H7.[27] This material, which is one of the most common touch surface materials in the healthcare industry, allows toxic E. coli O157:H7 to remain viable for weeks. Near-zero bacterial counts are not observed even after 28 days of investigation. Epifluorescence photographs have demonstrated that E. coli O157:H7 is almost completely killed on copper alloy C10200 after just 90 minutes at 20 °C; whereas a substantial number of pathogens remain on stainless steel S30400.[23]


Methicillin-resistant Staphylococcus aureus (MRSA) is a dangerous bacteria strain because it is resistant to beta-lactam antibiotics.[33][34] Recent strains of the bacteria, EMRSA-15 and EMRSA-16, are highly transmissible and durable. This is of extreme importance to those concerned with reducing the incidence of hospital-acquired MRSA infections.

In 2008, after evaluating a wide body of research mandated specifically by the United States Environmental Protection Agency (EPA), registration approvals were granted by EPA in 2008 granting that copper alloys kill more than 99.9% of MRSA within two hours.

Subsequent research conducted at the University of Southampton (UK) compared the antimicrobial efficacies of copper and several non-copper proprietary coating products to kill MRSA.[35][36] At 20 °C, the drop-off in MRSA organisms on copper alloy C11000 is dramatic and almost complete (over 99.9% kill rate) within 75 minutes. However, neither a triclosan-based product nor two silver-based antimicrobial treatments (Ag-A and Ag-B) exhibited any meaningful efficacy against MRSA. Stainless steel S30400 did not exhibit any antimicrobial efficacy.

In 2004, the University of Southampton research team was the first to clearly demonstrate that copper inhibits MRSA.[37] On copper alloys — C19700 (99% copper), C24000 (80% copper), and C77000 (55% copper) — significant reductions in viability were achieved at room temperatures after 1.5 hours, 3.0 hours and 4.5 hours, respectively. Faster antimicrobial efficacies were associated with higher copper alloy content. Stainless steel did not exhibit any bactericidal benefits.

Leyland Nigel S., Podporska-Carroll Joanna, Browne John, Hinder Steven J., Quilty Brid, Pillai Suresh C. (2016). “Highly Efficient F, Cu doped TiO2 anti-bacterial visible light active photocatalytic coatings to combat hospital-acquired infections”. Scientific Reports. 6. doi:10.1038/srep24770.

Clostridium difficile

Clostridium difficile, an anaerobic bacterium, is a major cause of potentially life-threatening disease, including nosocomial diarrheal infections, especially in developed countries.[38] C. difficile endospores can survive for up to five months on surfaces.[39] The pathogen is frequently transmitted by the hands of healthcare workers in hospital environments. C. difficile is currently a leading hospital-acquired infection in the UK,[40] and rivals MRSA as the most common organism to cause hospital acquired infections in the US.[41] It is responsible for a series of intestinal health complications, often referred to collectively as Clostridium difficile Associated Disease (CDAD).

The antimicrobial efficacy of various copper alloys against Clostridium difficile was recently evaluated.[42] The viability of C. difficile spores and vegetative cells were studied on copper alloys C11000 (99.9% copper), C51000 (95% copper), C70600 (90% copper), C26000 (70% copper), and C75200 (65% copper). Stainless steel (S30400) was used as the experimental control. The copper alloys significantly reduced the viability of both C. difficile spores and vegetative cells. On C75200, near total kill was observed after one hour (however, at 6 hours total C. difficile increased, and decreased slower afterwards). On C11000 and C51000, near total kill was observed after 3 hours, then total kill in 24 hours on C11000 and 48 hours on C51000. On C70600, near total kill was observed after 5 hours. On C26000, near total kill was achieved after 48 hours. On stainless steel, no reductions in viable organisms were observed after 72 hours (3 days) of exposure and no significant reduction was observed within 168 hours (1 week).

Influenza A

Influenza, commonly known as flu, is an infectious disease from a viral pathogen different from the one that produces the common cold. Symptoms of influenza, which are much more severe than the common cold, include fever, sore throat, muscle pains, severe headache, coughing, weakness and general discomfort. Influenza can cause pneumonia, which can be fatal, particularly in young children and the elderly.

After incubation for one hour on copper, active influenza A virus particles were reduced by 75%.[43][44] After six hours, the particles were reduced on copper by 99.999%. Influenza A virus was found to survive in large numbers on stainless steel.

Once surfaces are contaminated with virus particles, fingers can transfer particles to up to seven other clean surfaces.[45] Because of copper’s ability to destroy influenza A virus particles, copper can help to prevent cross-contamination of this viral pathogen.


Adenovirus is a group of viruses that infect the tissue lining membranes of the respiratory and urinary tracts, eyes, and intestines. Adenoviruses account for about 10% of acute respiratory infections in children.[citation needed] These viruses are a frequent cause of diarrhea.

In a recent study, 75% of adenovirus particles were inactivated on copper (C11000) within one hour. Within six hours, 99.999% of the adenovirus particles were inactivated. Within six hours, 50% of the infectious adenovirus particles survived on stainless steel.[44]


The antifungal efficacy of copper was compared to aluminium on the following organisms that can cause human infections: Aspergillus spp., Fusarium spp., Penicillium chrysogenum, Aspergillus niger and Candida albicans.[46] An increased die-off of fungal spores was found on copper surfaces compared with aluminium. Aspergillus niger growth occurred on the aluminium coupons[clarification needed] growth was inhibited on and around copper coupons.

*** Medical and General Disclaimer: All the information on this website – – is published in good faith and for general information purpose only. Any action you take upon the information you find on this website (, is strictly at your own risk. GaleForce Design Jewelry will not be liable for any losses and/or damages in connection with the use of our website. The information contained in or made available through cannot replace or substitute for the services of trained professionals in the medical field. We do not recommend any specific treatment, drug, food or supplement. The information contained on this website is not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional advice or delay in seeking it because of something you have read or received from the GaleForce Design Jewelry website. contains links to outside websites that are not maintained by GaleForce Design Jewelry. GaleForce Design Jewelry is not responsible for the content on nor does it endorse any site.***