scholarly journals Scalable in-hospital decontamination of N95 filtering face-piece respirator with a peracetic acid room disinfection system

2020 ◽  
pp. 1-10 ◽  
Author(s):  
Amrita R. John ◽  
Shine Raju ◽  
Jennifer L. Cadnum ◽  
Kipum Lee ◽  
Phillip McClellan ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Peracetic Acid ◽  
Structural Integrity ◽  
Filtration Efficiency ◽  
Material Structure ◽  
Cycle Duration ◽  
Bacteriophage Ms2 ◽  
Large Numbers ◽  
High Level ◽  
N95 Respirators

Abstract Background: Critical shortages of personal protective equipment, especially N95 respirators, during the coronavirus disease 2019 (COVID-19) pandemic continues to be a source of concern. Novel methods of N95 filtering face-piece respirator decontamination that can be scaled-up for in-hospital use can help address this concern and keep healthcare workers (HCWs) safe. Methods: A multidisciplinary pragmatic study was conducted to evaluate the use of an ultrasonic room high-level disinfection system (HLDS) that generates aerosolized peracetic acid (PAA) and hydrogen peroxide for decontamination of large numbers of N95 respirators. A cycle duration that consistently achieved disinfection of N95 respirators (defined as ≥6 log10 reductions in bacteriophage MS2 and Geobacillus stearothermophilus spores inoculated onto respirators) was identified. The treated masks were assessed for changes to their hydrophobicity, material structure, strap elasticity, and filtration efficiency. PAA and hydrogen peroxide off-gassing from treated masks were also assessed. Results: The PAA room HLDS was effective for disinfection of bacteriophage MS2 and G. stearothermophilus spores on respirators in a 2,447 cubic-foot (69.6 cubic-meter) room with an aerosol deployment time of 16 minutes and a dwell time of 32 minutes. The total cycle time was 1 hour and 16 minutes. After 5 treatment cycles, no adverse effects were detected on filtration efficiency, structural integrity, or strap elasticity. There was no detectable off-gassing of PAA and hydrogen peroxide from the treated masks at 20 and 60 minutes after the disinfection cycle, respectively. Conclusion: The PAA room disinfection system provides a rapidly scalable solution for in-hospital decontamination of large numbers of N95 respirators during the COVID-19 pandemic.

scholarly journals Scalable In-hospital Decontamination of N95 Filtering Facepiece Respirator with a Peracetic Acid Room Disinfection System

2020 ◽  
Author(s):  
Amrita R. John ◽  
Shine Raju ◽  
Jennifer L. Cadnum ◽  
Kipum Lee ◽  
Phillip McClellan ◽  
...  
Keyword(s):  
Peracetic Acid ◽  
Structural Integrity ◽  
Filtration Efficiency ◽  
Material Structure ◽  
Cycle Duration ◽  
Bacteriophage Ms2 ◽  
Large Numbers ◽  
Care Workers ◽  
High Level ◽  
N95 Respirators

AbstractBackgroundCritical shortages of personal protective equipment (PPE) especially N95 respirators, during the SARS-CoV-2 pandemic continues to be a source of great concern among health care workers (HCWs). Novel methods of N95 filtering facepiece respirator (FFR) decontamination that can be scaled-up for in-hospital use can help address this concern and keep HCWs safe.MethodsA multidisciplinary pragmatic study was conducted to evaluate the use of an ultrasonic room high-level disinfection system (HLDS) that generates aerosolized peracetic acid (PAA) and hydrogen peroxide for decontamination of large numbers of N95 respirators. A cycle duration that consistently achieved disinfection of N95 respirators (defined as ≤ 6 log10 reductions in bacteriophage MS2 and Geobacillus stearothermophilus spores inoculated onto respirators) was identified. The treated masks were then assessed for changes to their hydrophobicity, material structure, strap elasticity, and filtration efficiency (FE). Assessment of PAA off-gassing from a treated mask was also performed.ResultsThe PAA room HLDS was effective for disinfection of N95 respirators in a 2447 cubic feet room with deploy and dwell times of 16 and 32 minutes respectively, and a total cycle time of 1 hour and 16 minutes. After 5 treatment cycles, no adverse effects were detected on filtration efficiency, structural integrity, or strap elasticity. There was no detectable off-gassing of PAA from the treated masks.ConclusionThe PAA room disinfection system provides a rapidly scalable solution for in-hospital decontamination of large numbers of N95 respirators to meet the needs of HCWs during the SARS-CoV-2 pandemic.

scholarly journals Disinfection of N95 Respirators with Ozone

2020 ◽  
Author(s):  
Edward P Manning ◽  
Matthew D Stephens ◽  
Sannel Patel ◽  
Sylvie Dufresne ◽  
Bruce Silver ◽  
...  
Keyword(s):  
Ambient Air ◽  
Filtration Efficiency ◽  
Ozone Exposure ◽  
Healthcare Personnel ◽  
First Report ◽  
High Level ◽  
N95 Respirators ◽  
Airtight Chamber ◽  
Ozone Disinfection ◽  
Chamber Exposure

The coronavirus disease 2019 crisis is creating a shortage of personal protective equipment (PPE), most critically, N95 respirators for healthcare personnel. Our group was interested in the feasibility of ozone disinfection of N95 respirators as an alternative for healthcare professionals and organizations that might not have access to other disinfection devices. We tested the effectiveness of ozone on killing Pseudomonas aeruginosa (PsA) on three different N95 respirators: 3M 1860, 3M 1870, and 3M 8000. We used an ozone chamber that consisted of: an airtight chamber, an ozone generator, an ozone destruct unit, and an ozone UV analyzer. The chamber was capable of concentrating ozone up to 500 parts per million (ppm) from ambient air, creating an airtight seal, and precisely measuring ozone levels within the chamber. Exposure to ozone at 400 ppm with 80% humidity for two hours effectively killed bacteria on N95 respirators, types 1860, 1870, and 8000. There were no significant changes in filtration efficiency of the 1860 and 1870 type respirators for up to ten cycles of ozone exposure at similar conditions. There was no change in fit observed in the 1870 type respirator after ozone exposure. There was no significant change in the strap integrity of the 1870 type respirator after ozone exposure. Tests for filtration efficiency were not performed on the 8000 type respirator. Tests for fit or strap integrity were not performed on the 8000 or 1860 type respirators. This study demonstrates that an ozone application achieves a high level of disinfection against PsA, a vegetative bacteria that the CDC identifies as more difficult to kill than medium sized viruses such as SARS-CoV-2 (Covid-19). Furthermore, conditions shown to kill these bacteria did not damage or degrade respirator filtration. This is the first report of successful disinfection of N95 PPE with ozone of which the authors are aware. It is also the first report, to the authors' knowledge, to identify necessary conditions for ozone to kill organisms on N95 masks without degrading the function of N95 filters.

Disinfection of Endoscopes: Review of New Chemical Sterilants Used for High-Level Disinfection

1999 ◽  
Vol 20 (01) ◽  
pp. 69-76 ◽  
Author(s):  
William A. Rutala ◽  
David J. Weber
Keyword(s):  
Hydrogen Peroxide ◽  
Infection Control ◽  
Peracetic Acid ◽  
Advantages And Disadvantages ◽  
High Level ◽  
Patient Use ◽  
System 1

AbstractChemical sterilants are used to high-level disinfect heat-sensitive semicritical items such as endoscopes. Most endoscopes have been reprocessed between each patient use with glutaraldehyde (>2%) or the Steris System 1. Several new chemical sterilants have been developed recently, including 7.5% hydrogen peroxide, 0.08% peracetic acid plus 1.0% hydrogen peroxide, and 0.55% orthophthalaldehyde. In order to aid the infection control professional in choosing the appropriate disinfection methodology, this article reviews the characteristics, advantages, and disadvantages of high-level disinfectants intended for reprocessing endoscopes.

scholarly journals Validation of N95 filtering facepiece respirator decontamination methods available at a large university hospital

2020 ◽  
Author(s):  
Krista R. Wigginton ◽  
Peter J. Arts ◽  
Herek Clack ◽  
William J Fitzsimmons ◽  
Mirko Gamba ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Relative Humidity ◽  
Hepatitis Virus ◽  
Biological Indicators ◽  
Biological Indicator ◽  
Filtration Efficiency ◽  
Full Scale ◽  
Moist Heat ◽  
N95 Respirators ◽  
The Impact

AbstractImportanceFiltering facepiece respirators, including N95 masks, are a critical component of infection prevention in hospitals. Due to unprecedented shortages in N95 respirators, many healthcare systems have explored reprocessing of N95 respirators. Data supporting these approaches are lacking in real hospital settings. In particular, published studies have not yet reported an evaluation of multiple viruses, bacteria, and fungi along with respirator filtration and fit in a single, full-scale study.ObjectiveWe initiated a full-scale study to evaluate different N95 FFR decontamination strategies and their impact on respirator integrity and inactivating multiple microorganisms, with experimental conditions informed by the needs and constraints of the hospital.MethodsWe explored several reprocessing methods using new 3M™ 1860 N95 respirators, including dry (<10% relative humidity) and moist (62-66% relative humidity) heat (80-82 °C) in the drying cycle of industrial instrument washers, ethylene oxide (EtO), pulsed xenon UV (UV-PX), hydrogen peroxide gas plasma (HPGP), and vaporous hydrogen peroxide (VHP). Respirator samples were treated and analyzed for biological indicator inactivation using four viruses (MS2, phi6, influenza A virus, murine hepatitis virus), three bacteria (Escherichia coli, Staphylococcus aureus, Geobacillus stearothermophilus), and the fungus Aspergillus niger. The impact of different application media was also evaluated. In parallel, decontaminated respirators were evaluated for filtration integrity and fit.ResultsVHP resulted in >2 log10 inactivation of all tested biological indicators. The combination of UV-PX + moist heat resulted in >2 log10 inactivation of all biological indicators except G. stearothermohphilus. Greater than 95% filtration efficiency was maintained following 2 (UV-PX + <10% relative humidity heat) or 10 (VHP) cycles of treatment, and proper fit was also preserved. UV-PX + dry heat was insufficient to inactivate all biological indicators. Although very effective at virus decontamination, HPGP resulted in decreased filtration efficiency after 3 cycles, and EtO treatment raised potential toxicity concerns. The observed inactivation of viruses with UV-PX, heat, and hydrogen peroxide treatments varied as a function of which culture media (PBS buffer or DMEM) they were deposited in.Conclusions and RelevanceHigh levels of biological indicator inactivation were achieved following treatment with either moist heat or VHP. These same treatments did not significantly impact mask filtration or fit. Hospitals have a variety of scalable options to safely reprocess N95 masks. Beyond value in the current Covid-19 pandemic, the broad group of microorganisms and conditions tested make these results relevant in potential future pandemic scenarios.

What are the effective methods of decontaminating N95 mask for reuse?

2020 ◽  
Vol 54 ◽  
Author(s):  
Ian Theodore G. Cabaluna ◽  
Abigail F. Melicor
Keyword(s):  
Hydrogen Peroxide ◽  
Standard Care ◽  
Healthcare Workers ◽  
Structural Integrity ◽  
Influenza Viruses ◽  
Moist Heat ◽  
Ultraviolet Germicidal Irradiation ◽  
The Mean ◽  
N95 Respirators ◽  
Hydrogen Peroxide Vapor

KEY FINDINGS Based on laboratory-based studies, ultraviolet germicidal irradiation (UVGI), microwave generated steam, warm moist heat, and hydrogen peroxide vapor (HPV) were able to reduce the load of influenza viruses (A/H5N1, H1N1) or G. stearothermophilus and at the same time maintain the integrity of N95 respirators. • Considering the current pandemic, there is a potential for shortage of N95 facepiece filtering respirator (FFR) for healthcare workers. • No studies in humans were found comparing effectiveness of N95 post-decontamination. • Laboratory based studies done on influenza virus (A/H5N1, H1N1) have shown that ultraviolet germicidal irradiation, microwave generated steam, or warm moist heat was able to reduce the viral load by as much as 4 log and at the same time maintain respirator performance by keeping the percent penetration below 5% and the pressure drop within standards. • While UVGI was able to maintain integrity of FFRs up to 3 cycles, microwave generated steam may melt the metallic components of certain N95 masks. • Hydrogen peroxide vapor (HPV) had minimal effect on respirator performance and structural integrity up to 20 cycles and was also effective in eradicating G. stearothermophilus and aerosolized bacteriophages. • Bleach, ethanol and isopropanol all affected the mean penetration of the mask beyond the 5% limit. • The Centers for Disease Control (CDC) does not recommend decontamination then reuse of FFRs as standard care but decontamination with UVGI, HPV or moist heat may be considered as an option in FFR shortages.

scholarly journals Validation of N95 filtering facepiece respirator decontamination methods available at a large university hospital

2020 ◽  
Author(s):  
Krista R Wigginton ◽  
Peter J Arts ◽  
Herek Clack ◽  
William J Fitzsimmons ◽  
Mirko Gamba ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Influenza A ◽  
Hepatitis Virus ◽  
Biological Indicator ◽  
Filtration Efficiency ◽  
University Hospital ◽  
Murine Hepatitis Virus ◽  
Gas Plasma ◽  
Bacteria And Fungi ◽  
N95 Respirators

Abstract Background Due to unprecedented shortages in N95 filtering facepiece respirators, healthcare systems have explored N95 reprocessing. No single, full-scale reprocessing publication has reported an evaluation including multiple viruses, bacteria, and fungi along with respirator filtration and fit. Methods We explored reprocessing methods using new 3M™ 1860 N95 respirators, including moist (50-75% relative humidity, RH) heat (80-82 oC for 30 minutes), ethylene oxide (EtO), pulsed xenon UV-C (UV-PX), hydrogen peroxide gas plasma (HPGP), and hydrogen peroxide vapor (HPV). Respirator samples were analyzed using four viruses (MS2, phi6, influenza A virus (IAV), murine hepatitis virus (MHV)), three bacteria (Escherichia coli, Staphylococcus aureus, Geobacillus stearothermophilus spores and vegetative bacteria), and Aspergillus niger. Different application media were tested. Decontaminated respirators were evaluated for filtration integrity and fit. Results Heat with moderate RH most effectively inactivated virus, resulting in reductions of &gt;6.6 log10 MS2, &gt;6.7 log10 Phi6, &gt;2.7 log10 MHV, and &gt;3.9 log10 IAV and prokaryotes, except for G. stearothermohphilus. HPV was moderately effective at inactivating tested viruses, resulting in 1.5 to &gt;4 log10 observable inactivation. S. aureus inactivation by HPV was limited. Filtration efficiency and proper fit were maintained following 5 cycles of heat with moderate RH, and HPV. Although effective at decontamination, HPGP resulted in decreased filtration efficiency, and EtO treatment raised toxicity concerns. Observed virus inactivation varied depending upon the application media used. Conclusion Both moist heat and HPV are scalable N95 reprocessing options as they achieve high levels of biological indicator inactivation while maintaining respirator fit and integrity.

scholarly journals Aerosolized Hydrogen Peroxide Decontamination of N95 Respirators, with Fit-Testing and Virologic Confirmation of Suitability for Re-Use During the COVID-19 Pandemic

2020 ◽  
Author(s):  
T. Hans Derr ◽  
Melissa A. James ◽  
Chad V. Kuny ◽  
Devanshi Patel ◽  
Prem P. Kandel ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Healthcare Providers ◽  
Biological Indicators ◽  
Filtration Efficiency ◽  
Virus Inactivation ◽  
Virus Species ◽  
Viral Pathogen ◽  
Low Concentration ◽  
Fit Testing ◽  
N95 Respirators

AbstractIn response to the current demand for N95 respirators by healthcare workers responding to the COVID-19 pandemic, we evaluated decontamination of N95 respirators using a low concentration aerosolized hydrogen peroxide (aHP) system. This system dispenses a consistent atomized spray of micron-sized, low concentration, hydrogen peroxide (H2O2) particles over a treatment cycle. Multiple N95 respirator models were subjected to ten or more cycles of respirator decontamination, and masks were periodically assessed for qualitative and quantitative fit testing to verify respirator integrity. In parallel, we assessed the ability of aHP treatment to inactivate multiple viruses absorbed onto masks, including phi6 bacteriophage, HSV-1, CVB3, and SARS-CoV-2. Given that SARS-CoV-2 is transmitted via expired respiratory droplets and aerosols, it is critical to address respirator safety for reuse. This study provided experimental validation of a suitable aHP treatment process that decontaminates the respirators while maintaining N95 function. After ten rounds of aHP treatment, respirators passed N95 filtration efficiency testing. Virus inactivation by aHP was comparable to the sterilization of commercial spore-based biological indicators. These data demonstrate that the aHP process is effective, on the basis of zero failure rate on fit-testing of respirators, effective decontamination of multiple virus species including SARS-CoV-2, successful sterilization of bacterial spores, and filtration efficiency maintained at or greater than 95%. Collectively, these studies support the use of specific aHP decontamination protocol that permits safe reuse of N95 respirators by healthcare providers.ImportanceThe ongoing COVID-19 pandemic has led to unprecedented pressure on healthcare and research facilities to provide adequate personal protective equipment. Given that the current pandemic is caused by a respiratory viral pathogen, the availability of highly protective respirator facepieces is critical to limit inhalation of this virus. While respirator facepieces were designed for single-use and disposal, the pandemic has increased overall demand for N95 respirators, and corresponding manufacturing and supply chain limitations have necessitated the safe reuse of respirators when necessary. The biosafety level 3 (BSL3) facility used in this study regularly utilizes aerosolized hydrogen peroxide (aHP) to decontaminate equipment and spaces. We repurposed this technology for N95 respirator decontamination during the COVID-19 pandemic. Results from virus inactivation, biological indicators, respirator fit testing, and filtration efficiency testing all indicated that the process was effective at rendering N95 respirator safe for reuse.

Negotiations over Accounting Issues: The Congruency of Audit Partner and Chief Financial Officer Recalls

2005 ◽  
Vol 24 (s-1) ◽  
pp. 171-193 ◽  
Author(s):  
Michael Gibbins ◽  
Susan A. McCracken ◽  
Steven E. Salterio
Keyword(s):  
Negotiation Process ◽  
Chief Financial Officers ◽  
Chief Financial Officer ◽  
Relative Importance ◽  
Common Elements ◽  
Contextual Features ◽  
Large Numbers ◽  
The Common ◽  
High Level ◽  
Two Sides

Much of what takes place in auditor-client management negotiations occurs in unobservable settings and normally does not result in publicly available archival records. Recent research has increasingly attempted to probe issues relating to accounting negotiations in part due to recent events in the financial world. In this paper, we compare recalls from the two sides of such negotiations, audit partners, and chief financial officers (CFOs), collected in two field questionnaires. We examine the congruency of the auditors' and the CFOs' negotiation recalls for all negotiation elements and features that were common across the two questionnaires (detailed analyses of the questionnaires are reported elsewhere). The results show largely congruent recall: only limited divergences in recall of common elements and features. Specifically, we show a high level of congruency across CFOs and audit partners in the type of issues negotiated, parties involved in resolving the issue, and the elements making up the negotiation process, including agreement on the relative importance of various common accounting contextual features. The analysis of the common accounting contextual features suggests that certain contextual features are consistently important across large numbers of negotiations, whether viewed from the audit partner's or the CFO's perspective, and hence may warrant future study. Finally, the comparative analysis allows us to identify certain common elements and contextual features that may influence both audit partners and CFOs to consider the accounting negotiation setting as mainly distributive (win-lose).

Heritability of the Effect of Corticosteroids on Intraocular Pressure

1970 ◽  
Vol 19 (1-2) ◽  
pp. 264-267 ◽  
Author(s):  
F.H. Reuling ◽  
J.T. Schwartz
Keyword(s):  
Intraocular Pressure ◽  
Clinical Signs ◽  
Topical Steroids ◽  
Frequency Distributions ◽  
Steroid Response ◽  
Large Numbers ◽  
Wide Range ◽  
Allele Pair ◽  
High Level ◽  
Genetically Determined

In the late 1950's and early 1960's, it became evident that some glaucoma patients developed elevations of intraocular pressure, which were difficult to control, following prolonged use of systemic or ocular medications containing corticosteroids (Chandler, 1955, Alfano, 1963; Armaly, 1963). In addition, some patients without glaucoma, when treated with steroids for long periods of time, developed clinical signs of chronic simple glaucoma (McLean, 1950; François, 1954; Covell, 1958; Linner, 1959; Goldman, 1962). Fortunately, the elevation of intraocular pressure was reversible if the drug was discontinued.Over the past decade, extensive investigation of the “steroid response” has been undertaken. For this presentation, the steroid response may be considered as a gradual elevation of intraocular pressure, occurring over several weeks, in an eye being medicated with corticosteroid drops several times a day. The elevation in pressure is usually accompanied by a reduction in the facility of aqueous outflow. When relatively large numbers of subjects were tested with topical steroids, so that a wide range of responsiveness could be observed, a variation in individual sensitivity was demonstrated. Frequency distributions of intraocular pressure or change in pressure following steroids showed a skew toward the high side. On the basis of trimodal characteristics which they observed in such frequency distributions, Becker and Hahn (1964), Becker (1965) and Armaly (1965, 1966) considered the possible existence of several genetically determined subpopulations. These investigators distinguished three subpopulations on the basis of low, intermediate, and high levels of pressure response. It was hypothesized that these levels of response characterized three phenotypes, corresponding to the three possible genotypes of an allele pair, wherein one member of the pair determined a low level of response, and the other member determined a high level of response (Armaly, 1967).

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