Dry Heat as a Decontamination Method for N95 Respirator Reuse

Abstract

<div> <div> <p>A pandemic such as COVID-19 can cause a sudden depletion in the worldwide supply of respirators, forcing healthcare providers to reuse them. In this study, we systematically evaluated dry heat treatment as a viable option for the safe decontamination of N95 respirators (1860, 3M) before its reuse. We found that the dry heat generated by an electric cooker (100°C, 5% relative humidity, 50 min) effectively inactivated Tulane virus (>5.2-log<sub>10</sub> reduction), rotavirus (>6.6-log<sub>10</sub> reduction), adenovirus (>4.0-log<sub>10</sub> reduction), and transmissible gastroenteritis virus (>4.7-log<sub>10</sub> reduction). The respirator integrity (determined based on the particle filtration efficiency and quantitative fit testing) was not compromised after 20 cycles of 50-min dry heat treatment. Based on these results, we propose dry heat decontamination generated by an electric cooker (e.g., rice cookers, instant pots, ovens) to be an effective and accessible decontamination method for the safe reuse of N95 respirators.<br></p> </div> </div>

Effects of surface charge and environmental factors on the electrostatic interaction of fiber with virus-like particle: A case of coronavirus

“… 30–33 Understanding the interaction force between the virus and inanimate substrate, such as fiber, is essential to study the filtration process 34,35 and decontamination method. 36–38 …”

Decontamination and Reuse of N95 Filtering Facepiece Respirators: Where Do We Stand?

“…Most studies report preserved filter function following T ≤100°C. 36 , 37 , 52 , 61 , 62 , 65 , 67 , 68 Aerosol filtration was retained in 6 N95 models after dry heat ≤90°C × 1 hour but deteriorated following T ≥100°C. 37 Using fewer models, recent reports also found preserved N95 filtration following 20 heat cycles ≤100°C with wide-ranging RH, 62 , 67 , 68 although high RH with T>85°C may decrease electret function.…”

“… 52 Daeschler et al 65 completely inactivated SARS-CoV-2 on N95 fabric from 4 N95 models with 70°C dry heat × 60 minutes. Oh et al 67 inactivated 4 surrogate viruses on 1 FFR model fabric using a cooker to deliver 100°C dry × 50 minutes.…”

“…Ou tested 1 model after 10 cycles, 77°C x 30 minutes. 68 Oh et al 67 tested 1 model after 20 cycles, 100°C 5%RH × 50 minutes in a cooker.…”

Photosensitized Electrospun Nanofibrous Filters for Capturing and Killing Airborne Coronaviruses under Visible Light Irradiation

“…The copyright holder for this preprint (which this version posted July 30, 2021. ; https://doi.org/10.1101/2021.07.29.454404 doi: bioRxiv preprint hydrogen peroxide vapor, [46][47][48] photosensitized electrospun air filters generate broad-spectrum biocides of 1 O2 in situ under visible light exposure at the room temperature and pressure, and 1 O2 could potentially damage multiple viral biomolecules and multiple steps in viral lifecycle to effectively inactivate coronaviruses. Photosensitized disinfection is less chemical and energy intensive, and it does not compromise the aerosol filtration efficiency after disinfection.…”