The recent coronavirus pandemic has shown us that our public facilities are largely ill-prepared for mitigating germ spread.
As we become hyper-aware of the surfaces around us and how they contribute to the transfer of germs, copper, the material already critical to the development of so many advanced technologies, is receiving attention for its potential in building a less bacteria-friendly environment for the future as the antimicrobial coatings market is expected to witness significant growth in the coming years, with many predicting copper as the front runner.
Copper as an Antimicrobial
Copper (along with its alloys) has long been recognized for its antimicrobial properties, essentially serving as a self-disinfecting surface. Studies have shown that copper surfaces can kill more than 99.9% of the following disease-causing bacteria within 2 hours via “contact killing:”¹
- Staphylococcus aureus
- Enterobacter aerogenes
- Escherichia coli O157:H7
- Pseudomonas aeruginosa
- Vancomycin-resistant Enterococcus faecalis (VRE)
- Methicillin-resistant S. aureus (MRSA)
Similarly, a study conducted in the poultry industry found a polished copper surface could kill salmonella and listeria in less than four minutes.²
Copper’s ability to ward off infection was discovered when a physician began investigating on a hunch in the 1800s, after noticing that people working with copper were evading cholera epidemics (though in fact, records of copper’s effectiveness in medical applications exist as far back as the ancient Egyptians).
Copper was subsequently used as an antimicrobial in medical applications until 1932, when antibiotics became commercially available.³
Several factors have renewed interest in the use of copper as a tool in the war on bacteria, not the least of which has been the coronavirus pandemic. According to the National Institutes of Health, one recent study on the coronavirus investigated how long the virus lives on various contact surfaces and found that while other surfaces harbored viral activity for days, the virus could not be found on copper surfaces after just four hours.4 (A statement on the Copper Development Association’s antimicrobial copper stewardship website reads: “Due to an influx of inquiries from the media and external stakeholders, see the following page for clarifying statements on copper alloys and COVID-19 developed as part of the CDA’s EPA-mandated stewardship plan.” )
Copper is even now being studied as a potential antibiotic in itself.5 Its antimicrobial qualities have also been employed in agriculture, where products containing compounds of the red metal aid in crop protection.6
The Push for Antimicrobial Copper
While the coronavirus has further emphasized the need for added germ protection throughout society, researchers and medical professionals have been talking about copper as an antimicrobial for several other reasons in recent years:
The Need to Lower Healthcare-Associated Infections
Healthcare-associated infections (HAI), or infections acquired during a hospital stay or other healthcare-related treatment, though on the decline, still represent a major problem in the healthcare system, affecting about 3% of hospital patients, according to the CDC. HAIs present a risk to both patients and healthcare providers, killing thousands of people each year. They also increase healthcare costs significantly.
Hospital cleanliness and sterilization practices are already scrupulously managed. Implementing self-disinfecting surfaces like copper, in addition to regular cleaning practices, could substantially reduce the potential for spread.
One infamous study conducted by Microbiology and Immunology Professor at the Medical University of South Carolina, Michael Schmidt, showed an incredible 58% infection reduction in hospitals employing copper alloys on commonly touched surfaces.7
The Growing Threat of Antibiotic-Resistant Bacteria
Since their advent, the use of antibiotics has bred antibiotic-resistant strains of bacteria. These antibiotic-resistant bacteria are recognized by the CDC as one of the most pressing public health issues, because they are difficult and sometimes impossible to treat, killing an estimated 35,000 people in the US alone each year. This constant bacterial evolution puts public health at risk by taking away our ability to treat and manage infection spread.
As a result, alternative approaches to managing bacteria are necessary, and copper looks good for the job; not only does copper kill bacteria, but it actually destroys the bacteria’s DNA, preventing it from evolving into a more resistant strain.
Copper’s Ability to Work Passively and Tirelessly
Another key advantage of copper surfaces is that their germ-killing ability is always working, even after becoming tarnished. And, copper’s disinfecting properties never diminish. One group looked at the copper railings installed more than a century ago in New York City’s Grand Central Station and found them to be just as effective as the day they were installed.7
Using copper for common touch points in public facilities would serve as an infallible 24/7 disinfectant. In 2008, the US EPA officially recognized copper as the first metallic antimicrobial agent, paving the way for widespread use.
Conclusion
As copper’s infiltration into our everyday lives continues, now with applications in antimicrobial surface coatings, efficient copper processing will become more important than ever in meeting the world’s growing demand for this critical metal.
FEECO has been working with copper producers for decades, providing feasibility testing and process development services, copper processing equipment to maximize recovery, metal recovery technologies, and even parts and service support. For more information on our copper processing capabilities, contact us today!