If you’ve been on the hunt for a mask lately, you might have stumbled across one that contains copper. And if you’re not dialed into the latest on microbial surfaces, this might raise some questions. Why copper? And is it worth spending the extra money?
The answer is complicated. “I have great hopes for copper masks,” says Michael Schmidt, a professor of microbiology and immunology at the Medical University of South Carolina, who has studied the use of copper in medical products. “But there is a lot of research that still needs to be done about [their] effectiveness. If you’re just throwing copper layers onto a mask, we don’t [know] if they work.” Here are some things to consider the next time you see a pop-up ad for a copper mask.
Copper can destroy bacteria and viruses, as my colleague Mark Wilson recently reported. It contains positively charged ions that trap viruses that are negatively charged. Then the copper ions penetrate the viruses, stopping them from replicating. A recent study found that copper is effective at inactivating the novel coronavirus within four hours.
Historically, copper has been used in hospital door knobs and IV stands to curb the spread of illness. It has also been used in fabric. Schmidt points to an innovator in this space, Virginia-based Cupron, which invented a copper-infused fabric more than a decade ago. These fabrics have been made into bedsheets and pillowcases in hospitals. Microbiologist Phyllis Kuhn was another early advocate of using copper in hospitals. She developed a mask made from 99.95% copper mesh, which she sells on her website for $25.
Now, as coronavirus has swept across the planet and forced more people to wear masks, more companies are thinking about incorporating copper into masks. Companies like shoe startup Atoms, The Futon Shop, and an Israeli tech company called Argaman have all started selling copper masks, which cost between $10 and $70 a pop. “These fabrics have been around for some time—it’s just COVID that makes it new again,” Schmidt says.
Cupron, for instance, has started making cloth masks that contain a mix of cotton fibers and polyester blended with cotton, although they’re not available for individual purchase. Last week, the University Hospitals of Cleveland Medical Center bought 25,000 for employees. Daniel Simon, the chief clinical and scientific officer of UHCMC, says that N95 and surgical masks are being reserved for workers caring for confirmed COVID-19 patients. Meanwhile, the copper masks will be worn by all other employees. “We believe copper masks are more effective at protecting our workers than a simple cloth mask because the copper in them kills germs,” Simon says.
How is a copper mask better?
Right now, most copper masks on the market aren’t respirators, like the N95 mask, which creates a perfect seal around the wearer’s face. Instead, they’re looser-fitting cloth masks, which allow particles to enter through gaps in the side. These masks aren’t designed for people who are at high risk of being exposed to those with COVID-19.
Instead, they’re designed to be an improvement on the cloth masks that the CDC recommends people wear in public to curb the spread of the coronavirus. If a wearer is infected, virus-laden droplets that come out of their mouth or nose and land on the mask will be killed off in a matter of hours. On a cloth mask, they could live on the material for several days. In other words, these masks are designed to be more hygienic. “As the viral particles go out of you through the copper mask into the environment, they will die,” says Schmidt.
There are some benefits for the wearer as well. For instance, Cupron’s chief medical scientist says one way the virus could be transmitted is if someone touches an infected surface—like a doorknob—then touches their mask to adjust it. In this situation, the copper in the mask would kill these viruses, whereas they would linger on a traditional cloth mask, potentially contaminating the wearer. “The outside of a mask can pick up the virus,” Schmidt says. “You can pick it up with your fingers, rub your eye, pick your nose, lick your finger, and voila, you’re contaminated.”
However, the effectiveness of a mask depends on how much copper is in it, Schmidt says. Virus particles are very small, so they would need to actually encounter the copper to be deactivated. The best copper masks would have copper incorporated into every fiber, rather than just on one single layer embedded inside the mask.
Can they be washed?
One benefit of copper masks is that many are washable. While the specific details of washability vary, many copper masks—including Cupron’s and Phyllis Kuhn’s—can be washed repeatedly without reducing their efficacy. This is one reason that some hospitals, like UHCMC, are so eager to get their hands on them. “It’s hard procuring new PPE at a time when there is a global shortage,” says Simon. “With these copper masks, our workers can keep them for years and they will be just as effective.”
Schmidt says that copper is unlikely to interact with other chemicals, like cleaning solutions. He points out that copper is found in many everyday objects, including nickels and dimes. Most people aren’t allergic to these objects when they touch them, nor do they create adverse reactions with chemicals.
So should you buy a copper mask? Schmidt says that if a copper textile has been scientifically evaluated, it could be an improvement on the average cloth mask. The problem is that most copper masks on the market haven’t been studied.
Cupron’s copper masks—which are currently only available for institutions to purchase—have been studied and registered by the EPA, so Schmidt believes they’re trustworthy. But most other copper masks popping up haven’t been put to the test. “Many companies selling copper masks have not gone through the rigorous approach of getting their products registered or done studies to evaluate their masks,” says Schmidt. “They could just be bad copycats of Cupron’s mask.”
If you’re interested in purchasing a copper mask, Schmidt urges caution. “You need to know what you’re buying and how to properly use it,” he says. “Do your homework. Don’t buy the first mask you stumble across.”