But now, Duke University researchers have developed a method to clean them so they can be safely re-worn.
Using vaporized hydrogen peroxide, the researchers can kill microbial contaminants that lurk on the masks after they’re worn.
It’s a method labs have used for decades to decontaminate equipment, said Wayne Thomann, director emeritus of the Duke Occupational & Environmental Safety Office.
But the team never thought they’d need it for face masks.
How they do it
Decontaminating requires special equipment in a closed facility to handle the hydrogen peroxide. But the process has already been carried out at Duke Health hospital complexes and can occur at other hospitals, too.
Previous research showed that the respirators could be decontaminated and re-worn between 30 to 50 times, but Thomann and the biocontainment lab crew are still evaluating how often they can be re-worn after treating coronavirus patients.
“It will certainly be less than 30, and we will be conservative to ensure performance and safety,” Thomann told CNN in an email.
The masks tolerate the decontamination well, he said, so the process doesn’t damage them or make them less effective.
Before redistributing the respiratory masks, the team inspects them for tears to make sure they haven’t lost their shape — they must fit snugly and cover the entire mouth to be effective.
N95 masks are essential to fight coronavirus
And if physicians and nurses are sickened, there are fewer people to care for patients.
Decontaminating them keeps physicians fighting the coronavirus safer and bolsters hospitals’ efforts to treat patients, Thomann said.
“The N95 respirator is the most appropriate respiratory protection for patient care personnel attending Covid-19 patients, particularly performing aerosol-producing procedures on those patients,” he told CNN. “Reprocessing helps us ensure they will have the best PPE to protect them.”