When influenzas, bacteria like E. coli, superbugs like MRSA, or even coronaviruses land on most hard surfaces, they can live for up to four to five days. But when they land on copper, and copper alloys like brass, they begin to die within minutes and are undetectable within hours. “We’ve seen viruses just blow apart,” says Bill Keevil, professor of environmental healthcare at the University of Southampton. “They land on copper and it just degrades them.”
Copper is still widely used in power networks—the copper market is, in fact, growing because the material is such an effective conductor. But the material has been pushed out of many building applications by a wave of new materials from the 20th century. Plastics, tempered glass, aluminum, and stainless steel are the materials of modernity—used for everything from architecture to Apple products. Brass door knobs and handrails went out of style as architects and designers opted for sleeker-looking (and often cheaper) materials.
With funding from the Copper Development Association (a copper industry trade group), Keevil, working in his lab with some of the most feared pathogens in the world, has demonstrated that not only does copper kill bacteria efficiently; it also kills viruses. (In 2015, he even demonstrated this phenomenon with a precursor to COVID-19, coronavirus 229E).
In 2015, researchers working on a Department of Defense grant 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 pediatric intensive care unit, which charted a similarly impressive reduction in infection rate.
But what about expense? Copper is always more expensive than plastic or aluminum, and often a pricier alternative to steel. But given that hospital-borne infections are costing the healthcare system as much as $45 billion a year—not to mention killing as many as 90,000 people—the copper upgrade cost is negligible by comparison.
As for the rest of the world’s buildings that haven’t been updated to rip out the old copper fixtures, Keevil has a piece of advice: “Don’t remove them, whatever you do. These are the best things you’ve got.”