copper kills viruses and bacteria so why aren't our surfaces covered in it?

copper — a material with the power to kill bacteria and viruses in their tracks — has long been exploited for its health benefits. in ancient times, egyptian and babylonian soldiers would use it to sterilise their wounds; the greeks, romans and aztecs used it to treat headaches and ear infections; and in india, copper vessels have been used for millennia in the transportation of water. so why don’t we use it for surfaces in hospitals, toilets, or public spaces? well…

it’s right that today, we understand why copper is strong against viruses: because it is antimicrobial. it kills bacteria. when influenzas, bacteria like E. coli, superbugs like MRSA, they can die within minutes and are undetectable within hours. that’s a massive difference compared to the four to five days they can last on other surfaces. what’s more, copper and its alloys like brasses, bronzes, cupronickel, copper-nickel-zinc can self-sterilize its surface without the need for electricity or bleach.

studio liebel architekten wrapped this house in germany with perforated copper (image by brigida gonzález)| header image: the vessel in new york’s hudson yards is covered in copper-coated steel (image by michael moran for related-oxford)

during the repeated cholera epidemics in the mid-nineteenth century, physician victor burq discovered that using the material could help prevent widespread disease. he recommended using it for preventive and corrective ingestion of copper, after observing that smelter workers were unaffected by the disease. it turned out handling materials such as these back in the 19th century, where human’s understanding of hygiene was significantly less, was been similar to washing your hands.

designer nir shamir combines copper and ceramics to recreate a turkish coffee ritual
image courtesy of nir shamir

the studies continue — as fast company reports, using copper has been shown to reduce bacteria in health care settings by 90 percent. a study from 1983 found that hospital door knobs made of brass barely had any E. coli growth on them, compared to stainless steel knobs which were ‘heavily colonized.’ a more contemporary study, conducted by researchers working on a department of defense in 2015, compared infection rates at three hospitals, and found that when copper alloys were used in three hospitals, it reduced infection rates by 58%. a similar study was done in 2016 inside a paediatric intensive care unit, which charted a similarly impressive reduction in infection rate.

as a result of research like this, the united states environmental protection agency (EPA) has even approved the registrations of copper alloys as ‘antimicrobial materials with public health benefits’ allowing manufacturers to make legal claims to the public health benefits of products made of registered alloys. it has also approved a long list of antimicrobial copper products made from such alloys, like bedrails, handrails, over-bed tables, sinks, faucets, door knobs, toilet hardware, computer keyboards, health club equipment, and shopping cart handles.

so why don’t we make the most of this material today? while copper boomed during the industrial revolution as a material for objects, fixtures, and buildings it was later pushed out by new materials like plastic, tempered glass, aluminium and steel, along with a wave of modernism that done away with brass door knobs, replacing them with sleeker, more minimal styles in cheaper materials. in addition to that, there’s not enough data on copper and other technologies to make recommendations on what hospitals should do.

copper pipes and detailing adorn the interior of a themed pub called ‘refinery 091‘ 
image courtesy of nexus design

the research that has been conducted is significant because of how much of a problem healthcare-acquired infections are, not to mention the current climate. in the US alone, there are about 1.7 million infections and 99,000 deaths linked to hais per year, a total cost between $35.7 and $45 billion annually, from the extra treatments people need when they get infected.

this month, the virus that causes COVID-19 was shown to hang around on plastic packaging and plastic medical equipment for up to three days after contamination, according to a pre-print paper from researchers at the national institute of health. the team behind the paper looked at how long the virus that causes the new coronavirus (SARA-COV-2) can survive on different substances from cardboard to copper, comparing its lifespan to the virus that causes SARS (SARS-COV-1).

the results show that the COVID-19 virus appears to survive longest on polypropylene and stainless steel, where it can survive for two to three days after the initial contamination. on cardboard, it survived for nearly an entire day in some cases—up to 24 hours—post-contamination. not surprisingly, it lasted the least amount of time on copper, where it survived only up to four hours.