Standard hospital blanket warming cabinets can be utilized for complete moist heat SARS-CoV2 inactivation of contaminated N95 masks for re-use

Anand Kumar,Denis Laframboise,Jay Krishnan,Tracy Drew,Anders Leung,Olivero Orofino,Samantha B Kasloff,Naresh Sharma,Joe Tanelli,Gloria Vazquez-Grande,Todd Cutts

doi:10.1038/s41598-021-97345-w

Anand Kumar, Denis Laframboise + Show 9 more

Open Access

https://doi.org/10.1038/s41598-021-97345-w

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Abstract

Shortages of personal protective equipment for use during the SARS-CoV-2 pandemic continue to be an issue among health-care workers globally. Extended and repeated use of N95 filtering facepiece respirators without adequate decontamination is of particular concern. Although several methods to decontaminate and re-use these masks have been proposed, logistic or practical issues limit adoption of these techniques. In this study, we propose and validate the use of the application of moist heat (70 °C with humidity augmented by an open pan of water) applied by commonly available hospital (blanket) warming cabinets to decontaminate N95 masks. This report shows that a variety of N95 masks can be repeatedly decontaminated of SARS-CoV-2 over 6 h moist heat exposure without compromise of their filtering function as assessed by standard fit and sodium chloride aerosol filtration efficiency testing. This approached can easily adapted to provide point-of-care N95 mask decontamination allowing for increased practical utility of mask recycling in the health care setting.

Highlights

Shortages of personal protective equipment for use during the SARS-CoV-2 pandemic continue to be an issue among health-care workers globally
To determine whether the application of moist heat at 70 °C could decontaminate six different types of N95 respirators experimentally contaminated with SARS-CoV-2 without degrading fit and filtration efficiency over a series of decontamination cycles
Dry heat and relative humidity data measured from the middle shelf of the incubator without the pan of water showed the temperature and RH plateau at 71.5 °C and 3.5% respectively

Summary

Introduction

Shortages of personal protective equipment for use during the SARS-CoV-2 pandemic continue to be an issue among health-care workers globally. We report a simple decontamination method using a hospital blanket warming cabinet that could potentially be implemented at the local ward level and would substantially reduce logistic management issues allowing easy return of decontaminated respirators to their previous users. To determine whether the application of moist heat at 70 °C could decontaminate six different types of N95 respirators experimentally contaminated with SARS-CoV-2 without degrading fit and filtration efficiency over a series of decontamination cycles.

Results

Conclusion