Assessing changes to N95 respirator filtration efficiency, qualitative and quantitative fit, and seal check with repeated vaporized hydrogen peroxide (VHP) decontamination

2022 ◽  
Author(s):  
Christina F. Yen ◽  
Robert Seeley ◽  
Patrick Gordon ◽  
Lalitha Parameswaran ◽  
Sharon B Wright ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Filtration Efficiency ◽  
Qualitative And Quantitative

scholarly journals Evaluation of Enzymes Production Activity of Trichoderma, Aspergillus and Rhizopus Species in Paraeforce (Herbicide) Degradation

2020 ◽  
pp. 1-7
Author(s):  
F. I. Onianwah ◽  
H. O. Stanley ◽  
V. C. Eze ◽  
V. O. Ifeanyi ◽  
C. J. Ugboma
Keyword(s):  
Hydrogen Peroxide ◽  
Soil Samples ◽  
Laccase Production ◽  
Methyl Red ◽  
Aerobic Incubation ◽  
Fungal Isolation ◽  
Qualitative And Quantitative ◽  
Herbicide Degradation ◽  
Production Activity ◽  
Catalase Peroxidase

The study aims to evaluate enzymes that facilitate fungal degradation of paraeforce. Soil samples for fungal isolation were collected from impacted sites and inoculated on potato dextrose agar (PDA). The isolates were screened for growth and tolerance to paraefoce in 50 mg/l concentration of the test herbicides. Trichoderma, Aspergillus and Rhizopus species were found to grow in paraeforce supplemented PDA. Qualitative and quantitative assay for different enzyme production in hydrogen peroxide, methyl red, guaiacol and hydrogen peroxide-pyrogallol complex proved potential for catalase, lignin peroxidase, laccase and manganese peroxidase production, respectively. The results showed that these three fungi have great potential for catalase, peroxidase and laccase production after six days aerobic incubation in paraeforce and these enzymes facilitated the utilization of the paraeforce.  

scholarly journals Covid-19 respiratory protection: the filtration efficiency assessment of decontaminated FFP2 masks responding to associated shortages

2021 ◽  
Author(s):  
M. Benboubker ◽  
B. Oumokhtar ◽  
F. Hmami ◽  
K. El Mabrouk ◽  
L.EL Alami ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Structural Changes ◽  
Fourier Transforms ◽  
Chemical Characterization ◽  
Small Variation ◽  
Filtration Efficiency ◽  
Respiratory Protection ◽  
Filter Media ◽  
Test Protocol ◽  
Efficiency Measures

AbstractDuring the Covid-19 pandemic, healthcare workers were extremely vulnerable to infection with the virus and needed continuous protection. One of the most effective and widely used means of protection was the FFP2 respirator. Unfortunately, this crisis created a shortage of these masks, prompting hospitals to explore opportunities to reuse them after decontamination.An approach for assessing the filtration efficiency of decontaminated FFP2 masks has been proposed and applied to evaluate the possibilities of their safe reuse. The decontamination processes adopted are those based on moist heat or hydrogen peroxide. The approach introduces efficiency measures that define the filtration and protection capacity of the masks, which characterize both chemical and structural changes, and encompasses many techniques including scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The test protocol was applied to mask samples that had endured different decontamination cycles and the results of their efficiency measures were compared to brand-new masks’ performances.The main result was that chemical and structural characterization of the decontaminated masks have shown no substantial change or deformation of their filter media structures. Indeed, the respiratory resistance test has shown that the results of both the FFP2 masks that have undergone a hydrogen peroxide disinfection cycle or a steam autoclave cycle remained constant with a small variation of 10 Pa from the EN149 standard. The chemical characterization, on the other hand, has shown that the filter media of the decontaminated masks remains unchanged, with no detectable chemical derivatives in its constituents.

scholarly journals “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 ◽  
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.

scholarly journals In-House Filtration Efficiency Assessment of Vapor Hydrogen Peroxide Decontaminated Filtering Facepiece Respirators (FFRs)

2021 ◽  
Vol 18 (13) ◽  
pp. 7169
Author(s):  
Khaled Al-Hadyan ◽  
Ghazi Alsbeih ◽  
Ahmad Nobah ◽  
Jeffrey Lindstrom ◽  
Sawsan Falatah ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Fine Particle ◽  
High Stability ◽  
Production Control ◽  
Low Cost ◽  
Filtration Efficiency ◽  
Particle Sizes ◽  
Emergency Procedure ◽  
Efficiency Assessment ◽  
3D Printed

To cope with the shortage of filtering facepiece respirators (FFRs) caused by the coronavirus disease (COVID-19), healthcare institutions have been forced to reuse FFRs using different decontamination methods, including vapor hydrogen peroxide (VHP). However, most healthcare institutions still struggle with evaluating the effect of VHP on filtration efficiency (FE) of the decontaminated FFRs. We developed a low-cost in-house FE assessment using a novel 3D-printed air duct. Furthermore, we assessed the FE of seven types of FFRs. Following 10 VHP cycles, we evaluated the FE of KN95 and 3M-N95 masks. The 3M-N95 and Benehal-N95 masks showed significant lower FE (80.4–91.8%) at fine particle sizes (0.3–1 µm) compared to other FFRs (FE ≥ 98.1%, p < 0.05). Following 10 VHP cycles, the FE of KN95 masks was almost stable (FE stability > 99.1%) for all particle sizes, while 3M-N95 masks were stable only at 2 and 5 µm (FE stability > 98.0%). Statistically, FE stability of 3M-N95 masks at 0.3, 0.5, and 0.7 µm was significantly lower (p ≤ 0.006) than 2 and 5 µm. The in-house FE assessment may be used as an emergency procedure to validate the decontaminated FFRs, as well as a screening option for production control of FFRs. Following VHP cycles, both masks showed high stability at 5 µm, the size of the most suspected droplets implicated in COVID-19 transmission.

scholarly journals Decontamination and reuse of surgical masks and N95 filtering facepiece respirators during the COVID-19 pandemic: A systematic review

2020 ◽  
Vol 42 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Kachorn Seresirikachorn ◽  
Vorakamol Phoophiboon ◽  
Thitiporn Chobarporn ◽  
Kasenee Tiankanon ◽  
Songklot Aeumjaturapat ◽  
...  
Keyword(s):  
Systematic Review ◽  
Hydrogen Peroxide ◽  
Medical Personnel ◽  
Physical Structure ◽  
Filtration Efficiency ◽  
Level Of Evidence ◽  
Low Level ◽  
Moist Heat ◽  
Surgical Masks ◽  
Hydrogen Peroxide Vapor

AbstractObjectives:Surgical masks and N95 filtering facepiece respirators (FFRs) prevent the spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection and protect medical personnel. Increased demands for surgical masks and N95 FFRs during the coronavirus disease 2019 (COVID-19) pandemic has resulted in the shortage crisis. However, there is no standard protocol for safe reuse of the N95 FFRs. In this systematic review, we aimed to evaluate the effectiveness of existing decontamination methods of surgical masks and N95 FFRs and provide evidence-based recommendations for selecting an appropriate decontamination method.Methods:We performed systematic searches of Ovid MEDLINE and Ovid EMBASE electronic databases. The last search was performed April 11, 2020. Any trials studying surgical masks and/or N95 FFRs decontamination were included. Outcomes were disinfections of virus and bacteria, restoration of the filtration efficiency, and maintenance of the physical structure of the mask.Results:Overall, 15 studies and 14 decontamination methods were identified. A low level of evidence supported 4 decontamination methods: ultraviolet (UV) germicidal irradiation (9 studies), moist heat (5 studies), microwave-generated steam (4 studies), and hydrogen peroxide vapor (4 studies). Therefore, we recommended these 4 methods, and we recommended against use were given for the other 10 methods.Conclusions:A low level of evidence supported the use of UV germicidal irradiation, moist heat, microwave-generated steam, and hydrogen peroxide vapor for decontamination and reuse of N95 FFRs. These decontamination methods were effective for viral and bacterial disinfection as well as restoration of the filtration efficiency, and the physical structure of the FFRs.

scholarly journals Surgical masks decontamination for reuse by members of the public: feasibility study and development of home-based methods

2020 ◽  
Author(s):  
Mun Cheok Hong ◽  
Tan Sook Lan ◽  
Phua Soo Zeng Fiona ◽  
Lim Wei Qi ◽  
Pang Shyue Wei ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Staphylococcus Aureus ◽  
Ultraviolet Irradiation ◽  
Influenza A ◽  
H1n1 Influenza ◽  
Filtration Efficiency ◽  
The Public ◽  
Enveloped Virus ◽  
Log Reduction ◽  
Surgical Masks

Abstract This study aims to propose decontamination methods that are suitable for use by members of the public to cope with the shortage of surgical masks during the current COVID-19 pandemic. 3-ply surgical masks were subjected to different decontamination protocols (heat, chemical, ultraviolet irradiation) to assess their abilities to achieve at least 4-log reduction of two common respiratory pathogens, H1N1 Influenza A virus, a single-stranded RNA enveloped virus similar to SARS-CoV-2 and Staphylococcus aureus, a Gram-positive bacterium that is more resistant to decontamination than single stranded RNA enveloped virus. Decontaminated surgical masks were assessed for differences in breathability, particle filtration efficiency and bacteria filtration efficiency as compared with non-decontaminated masks. The number of decontamination cycles that the 3-ply surgical masks could undergo without significant changes in breathability and filtration efficiencies were also determined. It was found that surgical masks decontaminated by either soaking for 60 min in 0.5% (v/v) aqueous hydrogen peroxide solution, or 30 min of soaking in 0.05% - 0.5% (v/v) aqueous sodium hypochlorite diluted from household bleach or ultraviolet irradiation by a surface dose of 13.5 kJ/m2 were able to achieve at least a 4-log reduction of both Staphylococcus aureus and H1N1 Influenza A virus spiked on surgical mask test swatches. No significant changes in breathability and filtration efficiencies of the surgical masks were observed after ten decontamination cycles of hydrogen peroxide or diluted bleach treatment or 30 cycles of ultraviolet irradiation.

scholarly journals DEVELOPMENT AND RESEARCH OF ELECTROCATALYTIC SYSTEMS FOR ELECTRODES OF SOLID-OXIDE HYDROGEN-AIR FUEL CELLS

2021 ◽  
pp. 4-10
Author(s):  
M. K. Skakov ◽  
A. M. Zhilkashinova ◽  
S. K. Kabdrakhmanova ◽  
M. E. Seitkanova ◽  
E. Shaimardan ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Hydrogen Peroxide ◽  
Electronic Structure ◽  
Fuel Cell ◽  
Bimetallic Catalysts ◽  
Electrocatalytic Activity ◽  
Experimental Studies ◽  
Solid Oxide ◽  
Membrane Electrode ◽  
Qualitative And Quantitative

The article describes the results of experimental studies on the development of new active electrocatalysts for their use in the electrodes of the membrane-electrode block of a solid-oxide hydrogen-air fuel cell. Since the composition of the synthesized catalysts has a significant effect on its electrokinetic activity (electrical conductivity), the synthesis of nanoscale bimetallic catalysts of various qualitative and quantitative compositions is carried out. The choice of metal for the synthesis of the catalyst was determined by its electronic structure. The electrocatalytic activity of the developed catalysts was evaluated by studying the activity of the catalysts with respect to the decomposition of hydrogen peroxide. The developed bimetallic PVPD-Pt/ZnO/C catalysts exhibit activity with respect to the decomposition of hydrogen peroxide at 40–50 °C.

scholarly journals Evaluating N95 Respirator Filtration, Seal, Qualitative and Quantitative Fit with Vaporous Hydrogen Peroxide Reprocessing

2021 ◽  
Vol 1 (S1) ◽  
pp. s21-s21
Author(s):  
Christina Yen ◽  
Preeti Mehrotra ◽  
Dana Pepe ◽  
Sharon Wright ◽  
Patrick Gordon ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Filtration Rate ◽  
Factor Score ◽  
Significant Degree ◽  
Fisher Exact Test ◽  
Qualitative And Quantitative ◽  
Significant Difference ◽  
Fit Testing ◽  
N95 Respirators ◽  
Change In Mean

Background: The COVID-19 pandemic has created personal protective equipment (PPE) shortages, particularly of N95 respirators. Institutions have used decontamination strategies including vaporous hydrogen peroxide (VHP) to augment respirator supplies. VHP can be used to decontaminate nonporous surfaces without compromising material integrity. However, little is known about its impact on N95 respirator efficacy. We assessed whether repeated VHP reprocessing altered 4 key respirator efficacy qualities: quantitative fit, qualitative fit, seal check, and filtration rate. Methods: We conducted a prospective cohort study from June 15 to August 31, 2020. In total, 7 participants were fitted to a 3M 1860 small or regular N95 respirator based on qualitative and quantitative fit testing. Respirators underwent 25 disinfection cycles with the Bioquell BQ-50 VHP generator. After each cycle, participants donned and doffed respirators and performed a seal check. Participants were given 2 attempts to pass their seal check. Every 10 cycles, qualitative fit testing was done using an aerosolized Bitrex solution. Quantitative fit testing was conducted using a PortaCount Pro 8038 Fit Tester to generate a fit factor score. Appropriate fit is defined as a fit factor score of 100 or greater. Quantitative testing was done at cycles 1, 3, 5, 7, 10, 15, 20, and 25. Filtration efficiencies of particles ≥0.3 µm in diameter were measured using the TSI Optical Particle Sizer 3330 at cycles 1, 5, 10, 15, 20, and 25. The Fisher exact test was used to assess qualitative fit and seal check. The Kruskal-Wallis test was used to analyze quantitative fit and filtration rate. Results: We observed no seal-check or quantitative-fit test failures during the study window. All participants passed qualitative fit testing. Although there was a significant degree of variability in fit factor scores across disinfection cycles (mean score 163.5, p <0.05), there was no significant difference between participants (p = 0.6) (Figure 1). There was no statistically significant change in mean filtration rate from cycle 10 to 25 (P = .05), and the filtration rate remained >95% by cycle 25 (Figure 2). Conclusions: VHP reprocessing did not diminish the efficacy of N95 respirators based on the 4 metrics we assessed: filtration rate, seal check, qualitative fit, and quantitative fit. Of significance, the filtration rate remained well above the 95% standard filtration for N95 respirators—even through 25 cycles of reprocessing. VHP reprocessing is a safe, viable strategy to disinfect N95 respirators and extend their use, particularly during supply shortages.Funding: NoDisclosures: None

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