The use of germicidal ultraviolet light, vaporised hydrogen peroxide and dry heat to decontaminate face masks and filtering respirators contaminated with a SARS-CoV-2 surrogate virus

Background In the context of the ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, the supply of personal protective equipment remains under severe strain. To address this issue, re-use of surgical face masks and filtering facepiece respirators has been recommended; prior decontamination is paramount to their re-use. Aim We aim to provide information on the effects of three decontamination procedures on porcine respiratory coronavirus (PRCV)-contaminated masks and respirators, presenting a stable model for infectious coronavirus decontamination of these typically single-use-only products. Methods Surgical masks and filtering facepiece respirator coupons and straps were inoculated with infectious PRCV and submitted to three decontamination treatments, UV irradiation, vaporised H2O2, and dry heat treatment. Viruses were recovered from sample materials and viral titres were measured in swine testicle cells. Findings UV irradiation, vaporised H2O2 and dry heat reduced infectious PRCV by more than three orders of magnitude on mask and respirator coupons and rendered it undetectable in all decontamination assays. Conclusion This is the first description of stable disinfection of face masks and filtering facepiece respirators contaminated with an infectious SARS-CoV-2 surrogate using UV irradiation, vaporised H2O2 and dry heat treatment. The three methods permit demonstration of a loss of infectivity by more than three orders of magnitude of an infectious coronavirus in line with the FDA policy regarding face masks and respirators. It presents advantages of uncomplicated manipulation and utilisation in a BSL2 facility, therefore being easily adaptable to other respirator and mask types.

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RESEARCH: Dry Heat Processing of Single-Use Respirators and Surgical Masks

Biomedical Instrumentation & Technology ◽

10.2345/0899-8205-54.6.410 ◽

2020 ◽

Vol 54 (6) ◽

pp. 410-416

Author(s):

Joyce M. Hansen ◽

Scott Weiss ◽

Terra A. Kremer ◽

Myrelis Aguilar ◽

Gerald McDonnell

Keyword(s):

Microbial Contamination ◽

Healthcare Providers ◽

High Volume ◽

Airborne Particles ◽

Heat Processing ◽

Protective Equipment ◽

Healthcare Facilities ◽

Dry Heat ◽

Surgical Masks ◽

Single Use

The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2, has challenged healthcare providers in maintaining the supply of critical personal protective equipment, including single-use respirators and surgical masks. Single-use respirators and surgical masks can reduce risks from the inhalation of airborne particles and microbial contamination. The recent high-volume demand for single-use respirators and surgical masks has resulted in many healthcare facilities considering processing to address critical shortages. The dry heat process of 80°C (176°F) for two hours (120 min) has been confirmed to be an appropriate method for single-use respirator and surgical mask processing.

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“Don, doff, discard” to “don, doff, decontaminate”—FFR and mask integrity and inactivation of a SARS-CoV-2 surrogate and a norovirus following multiple vaporised hydrogen peroxide-, ultraviolet germicidal irradiation-, and dry heat decontaminations

PLoS ONE ◽

10.1371/journal.pone.0251872 ◽

2021 ◽

Vol 16 (5) ◽

pp. e0251872

Author(s):

Louisa F. Ludwig-Begall ◽

Constance Wielick ◽

Olivier Jolois ◽

Lorène Dams ◽

Ravo M. Razafimahefa ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Filtration Efficiency ◽

Murine Norovirus ◽

Ultraviolet Germicidal Irradiation ◽

Dry Heat ◽

Multiple Cycle ◽

Single Use ◽

Multiple Cycles ◽

Respiratory Coronavirus ◽

Porcine Respiratory

Background As the SARS-CoV-2 pandemic accelerates, the supply of personal protective equipment remains under strain. To combat shortages, re-use of surgical masks and filtering facepiece respirators has been recommended. Prior decontamination is paramount to the re-use of these typically single-use only items and, without compromising their integrity, must guarantee inactivation of SARS-CoV-2 and other contaminating pathogens. Aim We provide information on the effect of time-dependent passive decontamination (infectivity loss over time during room temperature storage in a breathable bag) and evaluate inactivation of a SARS-CoV-2 surrogate and a non-enveloped model virus as well as mask and respirator integrity following active multiple-cycle vaporised hydrogen peroxide (VHP), ultraviolet germicidal irradiation (UVGI), and dry heat (DH) decontamination. Methods Masks and respirators, inoculated with infectious porcine respiratory coronavirus or murine norovirus, were submitted to passive decontamination or single or multiple active decontamination cycles; viruses were recovered from sample materials and viral titres were measured via TCID50 assay. In parallel, filtration efficiency tests and breathability tests were performed according to EN standard 14683 and NIOSH regulations. Results and discussion Infectious porcine respiratory coronavirus and murine norovirus remained detectable on masks and respirators up to five and seven days of passive decontamination. Single and multiple cycles of VHP-, UVGI-, and DH were shown to not adversely affect bacterial filtration efficiency of masks. Single- and multiple UVGI did not adversely affect respirator filtration efficiency, while VHP and DH induced a decrease in filtration efficiency after one or three decontamination cycles. Multiple cycles of VHP-, UVGI-, and DH slightly decreased airflow resistance of masks but did not adversely affect respirator breathability. VHP and UVGI efficiently inactivated both viruses after five, DH after three, decontamination cycles, permitting demonstration of a loss of infectivity by more than three orders of magnitude. This multi-disciplinal approach provides important information on how often a given PPE item may be safely reused.

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Inhibitory Effect of Dry-Heat Treatment and Chemical Sanitizers against Foodborne Pathogens Contaminated on the Surfaces of Materials

Journal of the Korean Society of Food Science and Nutrition ◽

10.3746/jkfn.2009.38.9.1265 ◽

2009 ◽

Vol 38 (9) ◽

pp. 1265-1270 ◽

Cited By ~ 11

Author(s):

Young-Min Bae ◽

Sun-Gi Heu ◽

Sun-Young Lee

Keyword(s):

Heat Treatment ◽

Foodborne Pathogens ◽

Inhibitory Effect ◽

Dry Heat ◽

Dry Heat Treatment

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Effect of moist and dry-heat treatment processes on the structure, physicochemical properties, and in vitro digestibility of wheat starch-lauric acid complexes

Food Chemistry ◽

10.1016/j.foodchem.2021.129303 ◽

2021 ◽

Vol 351 ◽

pp. 129303

Author(s):

Xuemin Kang ◽

Wei Gao ◽

Bin Wang ◽

Bin Yu ◽

Li Guo ◽

...

Keyword(s):

Heat Treatment ◽

Physicochemical Properties ◽

Lauric Acid ◽

Wheat Starch ◽

In Vitro Digestibility ◽

Dry Heat ◽

Treatment Processes ◽

Dry Heat Treatment

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Kinetics of inactivating human parvovirus B19 and porcine parvovirus by dry-heat treatment

Transfusion ◽

10.1111/j.1537-2995.2008.01677.x ◽

2008 ◽

Vol 48 (4) ◽

pp. 790-790 ◽

Cited By ~ 11

Author(s):

Johannes Blümel ◽

Albert Stühler ◽

Herbert Dichtelmüller

Keyword(s):

Heat Treatment ◽

Parvovirus B19 ◽

Porcine Parvovirus ◽

Human Parvovirus B19 ◽

Dry Heat ◽

Dry Heat Treatment ◽

Kinetics Of

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Effect of dry heat treatment along with some dormancy breaking chemicals on oil palm seed germination

South African Journal of Botany ◽

10.1016/j.sajb.2017.06.023 ◽

2017 ◽

Vol 112 ◽

pp. 489-493

Author(s):

K.M. Tabi ◽

G.F. Ngando Ebongue ◽

G.N. Ntsomboh ◽

E. Youmbi

Keyword(s):

Heat Treatment ◽

Seed Germination ◽

Oil Palm ◽

Dormancy Breaking ◽

Dry Heat ◽

Dry Heat Treatment

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Improved heat stability of whey protein isolate stabilized emulsions via dry heat treatment of WPI and low methoxyl pectin: Effect of pectin concentration, pH, and ionic strength

Food Hydrocolloids ◽

10.1016/j.foodhyd.2016.10.025 ◽

2017 ◽

Vol 63 ◽

pp. 716-726 ◽

Cited By ~ 32

Author(s):

Arima Diah Setiowati ◽

Serveh Saeedi ◽

Wahyu Wijaya ◽

Paul Van der Meeren

Keyword(s):

Heat Treatment ◽

Ionic Strength ◽

Whey Protein ◽

Heat Stability ◽

Whey Protein Isolate ◽

Protein Isolate ◽

Dry Heat ◽

Dry Heat Treatment

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Germination, Outgrowth, and Vegetative-Growth Kinetics of Dry-Heat-Treated Individual Spores ofBacillusSpecies

Applied and Environmental Microbiology ◽

10.1128/aem.02618-17 ◽

2018 ◽

Vol 84 (7) ◽

Cited By ~ 2

Author(s):

Lin He ◽

Zhan Chen ◽

Shiwei Wang ◽

Muying Wu ◽

Peter Setlow ◽

...

Keyword(s):

Heat Treatment ◽

Spore Germination ◽

Differential Interference Contrast Microscopy ◽

Content Type ◽

Dry Heat ◽

Heat Treated ◽

Contrast Microscopy ◽

Interference Contrast Microscopy ◽

Dry Heat Treatment ◽

Kinetics Of

ABSTRACTDNA damage kills dry-heated spores ofBacillus subtilis, but dry-heat-treatment effects on spore germination and outgrowth have not been studied. This is important, since if dry-heat-killed spores germinate and undergo outgrowth, toxic proteins could be synthesized. Here, Raman spectroscopy and differential interference contrast microscopy were used to study germination and outgrowth of individual dry-heat-treatedB. subtilisandBacillus megateriumspores. The major findings in this work were as follows: (i) spores dry-heat-treated at 140°C for 20 min lost nearly all viability but retained their Ca2+-dipicolinic acid (CaDPA) depot; (ii) in most cases, dry-heat treatment increased the average times and variability of all major germination events inB. subtilisspore germination with nutrient germinants or CaDPA, and in one nutrient germination event withB. megateriumspores; (iii)B. subtilisspore germination with dodecylamine, which activates the spore CaDPA release channel, was unaffected by dry-heat treatment; (iv) these results indicate that dry-heat treatment likely damages spore proteins important in nutrient germinant recognition and cortex peptidoglycan hydrolysis, but not CaDPA release itself; and (v) analysis of single spores incubated on nutrient-rich agar showed that while dry-heat-treated spores that are dead can complete germination, they cannot proceed into outgrowth and thus not to vegetative growth. The results of this study provide new information on the effects of dry heat on bacterial spores and indicate that dry-heat sterilization regimens should produce spores that cannot outgrow and thus cannot synthesize potentially dangerous proteins.IMPORTANCEMuch research has shown that high-temperature dry heat is a promising means for the inactivation of spores on medical devices and spacecraft decontamination. Dry heat is known to killBacillus subtilisspores by DNA damage. However, knowledge about the effects of dry-heat treatment on spore germination and outgrowth is limited, especially at the single spore level. In the current work, Raman spectroscopy and differential interference contrast microscopy were used to analyze CaDPA levels in and kinetics of nutrient- and non-nutrient germination of multiple individual dry-heat-treatedB. subtilisandBacillus megateriumspores that were largely dead. The outgrowth and subsequent cell division of these germinated but dead dry-heat-treated spores were also examined. The knowledge obtained in this study will help understand the effects of dry heat on spores both on Earth and in space, and indicates that dry heat can be safely used for sterilization purposes.

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