The COVID-91 pandemic has created worldwide shortages of personal protective equipment, in particular, respiratory protection such as N95 respirators.
In general, N95 respirators are designed for single use prior to disposal. A study by the National Institutes of Health (NIH) has revealed three methods of effectively sanitizing the N95 masks for reuse.
Researchers tested small sections of N95 filter fabric that had been exposed to the coronavirus that causes COVID-19 using four decontamination methods:
- Vaporized hydrogen peroxide;
- 70° C dry heat;
- Ultraviolet light; and
- 70% ethanol spray.
The researchers then treated “fully intact, clean respirators” with the same decontamination methods to test their reuse durability. Volunteers wore the masks for two hours to determine if they maintained a proper fit and seal over the face; decontamination was repeated three times.
Vaporized hydrogen peroxide proved to be the most effective decontamination method, as no virus could be detected after only a 10-minute treatment. Further, the respirator showed no failures during the integrity testing process, suggesting it could be reused three times.
UV light and dry heat were acceptable methods as long as they were applied for at least 60 minutes, and the respirator began showing fit and seal issues after three decontaminations, leading to the conclusion that it could be reused only twice.
Ethanol spray, on the other hand, damaged the integrity of the respirator’s fit after two decontaminations, so is not recommended by NIH.
Anyone using decontamination methods to reuse N95 respirators is advised to check the fit and seal before each reuse.