Researchers Eliminate SARS-CoV-2 and Bacteria From N95 Masks With Low-Cost Moist Heat Treatment

N95 Face Mask

A new study shows that moist heat treatment of N95 masks eliminates severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and bacteria, which would allow reuse of these scarce resources. The study is published in CMAJ (Canadian Medical Association Journal).

The researchers found that moist heat treatment (60 min, 70°C, 50% relative humidity) did not damage the mask’s structure or affect function.

“This low-cost reprocessing strategy can be applied 10 times without affecting the mask’s filtration, breathing resistance, fit and comfort, and thus may help to alleviate the global shortage during the COVID-19 pandemic,” says Dr. Gregory Borschel, Institute of Biomaterials and Biomedical Engineering and Division of Plastic and Reconstructive Surgery, The Hospital for Sick Children (SickKids), Toronto, Ontario.

Researchers tested 4 common models of N95 masks at various temperatures and humidity levels to determine whether the virus could be detected on the treated masks. They also analyzed fibre samples for structural integrity and assessed function of the masks after treatment with heat.

“Thermal disinfection of N95 masks may provide a low-cost, effective method for regions with fewer resources to extend their supply of these critical resources, thereby protecting vulnerable front-line workers from job-related risk of infection,” says Dr. Borschel.

Reference: “Effect of moist heat reprocessing of N95 respirators on SARS-CoV-2 inactivation and respirator function” by Simeon C. Daeschler, Niclas Manson, Kariym Joachim, Alex W.H. Chin, Katelyn Chan, Paul Z. Chen, Aaron Jones, Kiana Tajdaran, Kaveh Mirmoeini, Jennifer J. Zhang, Jason T. Maynes, Libo Zhang, Michelle Science, Ali Darbandi, Derek Stephens, Frank Gu, Leo L.M. Poon and Gregory H. Borscheln, 30 July 2020, CMAJ (Canadian Medical Association Journal).
DOI: 10.1503/cmaj.201203

6 Comments on "Researchers Eliminate SARS-CoV-2 and Bacteria From N95 Masks With Low-Cost Moist Heat Treatment"

  1. I spray a fine mist with 70% alcohol to reuse it.

  2. Daniel Evans | August 2, 2020 at 9:39 pm | Reply

    Does the process for reuse of N-95 masks also kill other dangerous microbes to which the user might be exposed?

  3. Sterilization without cleaning is possible but disgusting. I’d rather not put my face against someone else’s secretions- dry and sterile or not. This goes against basic human decency in my mind. I bought a non-disposable filtration mask because my hospital is using this foul practice.

  4. Good to know information. Valved n95 masks provide little to no protection at all. You can also checkout a range of n95 masks over here.

  5. Or just wait 72 hours and reuse with no cleaning for most people

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