A National Institutes of Health study shows that N95 masks can be decontaminated and reused safely only two or three times, according to MedPage Today.
The study, which has not been peer-reviewed, analyzed four readily available and often used N95 mask decontamination methods, including ultraviolet light, a 70 percent ethanol solution, heat treatment and vaporized hydrogen peroxide.
Researchers found that ultraviolet light and vaporized hydrogen peroxide both killed the virus on N95 masks without affecting the functional integrity of the masks for two rounds of decontamination, compared to control masks that were not treated. Filtration remained "acceptable" after the mask was reused a third time when those two methods of decontamination were used.
The decontamination method using vaporized hydrogen peroxide was the faster than the ultraviolet light method, eliminating viral growth in about 10 minutes, MedPage Today reports.
The study also examined two other methods: using a 70 percent ethanol solution sprayed on the mask until saturated and heat treatment in an oven set to 158 degrees Fahrenheit for 10 minutes.
The ethanol decontaminated the masks quickly but did not preserve the functional integrity; the heat treatment was slow and took an hour to kill the virus but did preserve functional integrity for two rounds of decontamination, according to MedPage Today.