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1.
PLoS One ; 15(10): e0240499, 2020.
Article in English | MEDLINE | ID: covidwho-1388890

ABSTRACT

During the current SARS-CoV-2 pandemic there is unprecedented demand for personal protective equipment (PPE), especially N95 respirators and surgical masks. The ability of SARS-CoV-2 to be transmitted via respiratory droplets from asymptomatic individuals has necessitated increased usage of both N95 respirators in the healthcare setting and masks (both surgical and homemade) in public spaces. These precautions rely on two fundamental principles of transmission prevention: particle filtration and droplet containment. The former is the focus of NIOSH N95 testing guidelines, and the latter is an FDA guideline for respirators and surgical masks. While studies have investigated droplet containment to provide guidance for homemade mask production, limited work has been done to characterize the filtration efficiency (FE) of materials used in home mask making. In this work, we demonstrate the low-cost (<$300) conversion of standard equipment used to fit-test respirators in hospital and industrial settings into a setup that measures quantitative FEs of materials based on NIOSH N95 guidelines, and subsequently measure FEs of materials found in healthcare and consumer spaces. These materials demonstrate significant variability in filtration characteristics, even for visually similar materials. We demonstrate a FE of 96.49% and pressure drop of 25.4 mmH20 for a double-layer of sterilization wrap used in surgical suites and a FE of 90.37% for a combination of consumer-grade materials. The excellent filtration characteristics of the former demonstrate potential utility for emergent situations when N95 respirators are not available, while those of the latter demonstrate that a high FE can be achieved using publicly available materials.


Subject(s)
Air Filters/standards , Betacoronavirus , Coronavirus Infections/prevention & control , Equipment Safety/methods , Masks/standards , Materials Testing/methods , Pandemics/prevention & control , Personal Protective Equipment/standards , Pneumonia, Viral/prevention & control , Respiratory Protective Devices/standards , Aerosols , COVID-19 , Coronavirus Infections/virology , Equipment Safety/instrumentation , Health Personnel , Humans , Materials Testing/instrumentation , Occupational Exposure/prevention & control , Pneumonia, Viral/virology , SARS-CoV-2
2.
ACS Nano ; 14(7): 9188-9200, 2020 07 28.
Article in English | MEDLINE | ID: covidwho-1387153

ABSTRACT

Filtration efficiency (FE), differential pressure (ΔP), quality factor (QF), and construction parameters were measured for 32 cloth materials (14 cotton, 1 wool, 9 synthetic, 4 synthetic blends, and 4 synthetic/cotton blends) used in cloth masks intended for protection from the SARS-CoV-2 virus (diameter 100 ± 10 nm). Seven polypropylene-based fiber filter materials were also measured including surgical masks and N95 respirators. Additional measurements were performed on both multilayered and mixed-material samples of natural, synthetic, or natural-synthetic blends to mimic cloth mask construction methods. Materials were microimaged and tested against size selected NaCl aerosol with particle mobility diameters between 50 and 825 nm. Three of the top five best performing samples were woven 100% cotton with high to moderate yarn counts, and the other two were woven synthetics of moderate yarn counts. In contrast to recently published studies, samples utilizing mixed materials did not exhibit a significant difference in the measured FE when compared to the product of the individual FE for the components. The FE and ΔP increased monotonically with the number of cloth layers for a lightweight flannel, suggesting that multilayered cloth masks may offer increased protection from nanometer-sized aerosol with a maximum FE dictated by breathability (i.e., ΔP).


Subject(s)
Coronavirus Infections/prevention & control , Masks/standards , Pandemics/prevention & control , Personal Protective Equipment/standards , Pneumonia, Viral/prevention & control , Respiratory Protective Devices/standards , Textiles/standards , Aerosols/chemistry , Betacoronavirus/pathogenicity , COVID-19 , Filtration , Humans , Masks/virology , Nanoparticles/chemistry , Nanoparticles/virology , Personal Protective Equipment/virology , Respiratory Protective Devices/virology , SARS-CoV-2 , Textiles/adverse effects , Textiles/virology
4.
Am J Emerg Med ; 49: 172-177, 2021 Nov.
Article in English | MEDLINE | ID: covidwho-1260367

ABSTRACT

BACKGROUND: Airborne personal protective equipment is required for healthcare workers when performing aerosol-generating procedures on patients with infectious diseases. Chest compressions, one of the main components of cardiopulmonary resuscitation, require intense and dynamic movements of the upper body. We aimed to investigate the protective effect of tight-fitting powered air-purifying respirators (PAPRs) during chest compressions. METHODS: This single-center simulation study was performed from February 2021 to March 2021. The simulated workplace protection factor (SWPF) is the concentration ratio of ambient particles and particles inside the PAPR mask; this value indicates the level of protection provided by a respirator when subjected to a simulated work environment. Participants performed continuous chest compressions three times for 2 min each time, with a 4-min break between each session. We measured the SWPF of the tight-fitting PAPR during chest compression in real-time mode. The primary outcome was the ratio of any failure of protection (SWPF <500) during the chest compression sessions. RESULTS: Fifty-four participants completed the simulation. Overall, 78% (n = 42) of the participants failed (the measured SWPF value was less than 500) at least one of the three sessions of chest compressions. The median value and interquartile range of the SWPF was 4304 (685-16,191). There were no reports of slipping down of the respirator or mechanical failure during chest compressions. CONCLUSIONS: Although the median SWPF value was high during chest compressions, the tight-fitting PAPR did not provide adequate protection.


Subject(s)
Cardiopulmonary Resuscitation/adverse effects , Protective Factors , Respiratory Protective Devices/standards , Adult , Air Filters/standards , Air Filters/statistics & numerical data , Cardiopulmonary Resuscitation/methods , Female , Humans , Infection Control/methods , Infection Control/standards , Infection Control/statistics & numerical data , Male , Respiratory Protective Devices/statistics & numerical data , Surveys and Questionnaires
5.
J Hosp Infect ; 113: 180-186, 2021 Jul.
Article in English | MEDLINE | ID: covidwho-1275476

ABSTRACT

BACKGROUND: Public Health England guidance stipulates the use of filtering facepiece (FFP3) masks for healthcare workers engaged in aerosol-generating procedures. Mask fit-testing of respiratory protective equipment is essential to protect healthcare workers from aerosolized particles. AIM: To analyse the outcome of mask fit-testing across National Health Service (NHS) hospitals in the UK during the first wave of the coronavirus disease 2019 (COVID-19) pandemic. METHODS: Using the Freedom of Information Act, 137 NHS hospitals were approached on May 26th, 2020 by an independent researcher to provide data on the outcome of fit-testing at each site. FINDINGS: Ninety-six hospitals responded to the request between May 26th, 2020 to October 29th, 2020. There was a total of 86 mask types used across 56 hospitals, 13 of which were used in at least 10% of these hospitals; the most frequently used was the FFP3M1863, used by 92.86% of hospitals. Overall fit-testing pass rates were provided by 32 hospitals with mean pass rate of 80.74%. The most successful masks, in terms of fit-test failure rates, were the Alpha Solway 3030V and the Alpha Solway S-3V (both reporting mean fit-test failures of 2%). Male- and female-specific pass and failure rates were provided by seven hospitals. Across the seven hospitals, 20.1% of men tested failed the fit-test for all masks used, whereas 19.9% of women tested failed the fit-test for all masks used. Failure rates were significantly higher in staff from Black, Asian, and Minority Ethnic (BAME) backgrounds 644/2507 (25.69%) across four hospitals. CONCLUSION: Twenty percent of healthcare workers tested during the first response to the pandemic failed fit-testing for masks. A small sample revealed that this was most prominent in staff from BAME backgrounds.


Subject(s)
COVID-19/prevention & control , Health Personnel , Masks/standards , Occupational Exposure/prevention & control , Respiratory Protective Devices/standards , Female , Humans , Male , Pandemics , State Medicine , United Kingdom
6.
J Occup Environ Hyg ; 18(7): 334-344, 2021 07.
Article in English | MEDLINE | ID: covidwho-1254232

ABSTRACT

Homemade cloth masks and other improvised face coverings have become widespread during the COVID-19 pandemic driven by severe shortages of personal protective equipment. In this study, various alternative (mostly common household) materials, which have not traditionally been used in respiratory protective devices, were tested for particle filtration performance and breathability. Most of these materials were found of some-but rather limited-utility in facemasks. At a breathing flow rate of 30 L min-1, 17 out of 19 tested materials demonstrated collection efficiency below 50%; at 85 L min-1, only one material featured particle collection efficiency above 50%. Pressure drop values were mostly below 4 mm w.g. (observed in 89% of cases for the two flow rates), which provides comfortable breathing. Only for one fabric material (silk) tested at 85 L min-1 did the pressure drop reach 11 mm w.g. Based on these results, a three-layer facemask prototype was designed and fabricated comprised of the best performing materials. Additional tests were conducted to examine possible particle detachment/shedding from the materials used in the newly developed facemask, but no such phenomenon was observed. The prototype was evaluated on 10 human subjects using the standard OSHA-approved quantitative fit testing protocol. The mask protection level, determined as an adopted fit factor, was found to lie between that of the two commercial surgical/medical masks tested for comparison. A 10-cycle washing of the mask prototype lowered its collection efficiency across the particle size range; however, washing did not substantially affect mask breathability. The study revealed that although homemade masks offer a certain level of protection to a wearer, one should not expect them to provide the same respiratory protection as high-end commercial surgical/medical masks or-by any means-NIOSH-certified N95 filtering facepieces.


Subject(s)
COVID-19/prevention & control , Equipment Design , Filtration/instrumentation , Masks/standards , Materials Testing , Humans , Masks/supply & distribution , Occupational Exposure/prevention & control , Particle Size , Personal Protective Equipment/standards , Personal Protective Equipment/supply & distribution , Respiration , Respiratory Protective Devices/standards , Respiratory Protective Devices/supply & distribution , SARS-CoV-2 , Textiles
7.
J Occup Environ Hyg ; 17(11-12): 538-545, 2020.
Article in English | MEDLINE | ID: covidwho-790863

ABSTRACT

Powered air-purifying respirators (PAPRs) that offer protection from particulates are deployed in different workplace environments. Usage of PAPRs by healthcare workers is rapidly increasing; these respirators are often considered the best option in healthcare settings, particularly during public health emergency situations, such as outbreaks of pandemic diseases. At the same time, lack of user training and certain vigorous work activities may lead to a decrease in a respirator's performance. There is a critical need for real-time performance monitoring of respiratory protective devices, including PAPRs. In this effort, a new robust and low-cost real-time performance monitor (RePM) capable of evaluating the protection offered by a PAPR against aerosol particles at a workplace was developed. The new device was evaluated on a manikin and on human subjects against a pair of condensation nuclei counters (P-Trak) used as the reference protection measurement system. The outcome was expressed as a manikin-based protection factor (mPF) and a Simulated Workplace Protection Factor (SWPF) determined while testing on subjects. For the manikin-based testing, the data points collected by the two methods were plotted against each other; a near-perfect correlation was observed with a correlation coefficient of 0.997. This high correlation is particularly remarkable since RePM and condensation particle counter (CPC) measure in different particle size ranges. The data variability increased with increasing mPF. The evaluation on human subjects demonstrated that RePM prototype provided an excellent Sensitivity (96.3% measured on human subjects at a response time of 60 sec) and a Specificity of 100%. The device is believed to be the first of its kind to quantitatively monitor PAPR performance while the wearer is working; it is small, lightweight, and does not interfere with job functions.


Subject(s)
Aerosols/analysis , Equipment Failure Analysis/methods , Respiratory Protective Devices/standards , Manikins , Occupational Exposure/prevention & control , Particle Size , Sensitivity and Specificity , Sodium Chloride/chemistry
8.
PLoS One ; 16(2): e0246720, 2021.
Article in English | MEDLINE | ID: covidwho-1088757

ABSTRACT

Filtering facepiece respirators (FFRs) and medical masks are widely used to reduce the inhalation exposure of airborne particulates and biohazardous aerosols. Their protective capacity largely depends on the fraction of these that are filtered from the incoming air volume. While the performance and physics of different filter materials have been the topic of intensive study, less well understood are the effects of mask sealing. To address this, we introduce an approach to calculate the influence of face-seal leakage on filtration ratio and fit factor based on an analytical model and a finite element method (FEM) model, both of which take into account time-dependent human respiration velocities. Using these, we calculate the filtration ratio and fit factor for a range of ventilation resistance values relevant to filter materials, 500-2500 Pa∙s∙m-1, where the filtration ratio and fit factor are calculated as a function of the mask gap dimensions, with good agreement between analytical and numerical models. The results show that the filtration ratio and fit factor are decrease markedly with even small increases in gap area. We also calculate particle filtration rates for N95 FFRs with various ventilation resistances and two commercial FFRs exemplars. Taken together, this work underscores the critical importance of forming a tight seal around the face as a factor in mask performance, where our straightforward analytical model can be readily applied to obtain estimates of mask performance.


Subject(s)
Filtration/methods , Respiratory Protective Devices/statistics & numerical data , Aerosols/analysis , Air Filters , Equipment Design , Finite Element Analysis , Humans , Inhalation Exposure/analysis , Masks/statistics & numerical data , Masks/trends , Materials Testing/methods , Models, Theoretical , N95 Respirators/statistics & numerical data , Particle Size , Respiration , Respiratory Protective Devices/standards , Ventilators, Mechanical/statistics & numerical data , Ventilators, Mechanical/trends
9.
Int J Environ Res Public Health ; 18(4)2021 02 08.
Article in English | MEDLINE | ID: covidwho-1079658

ABSTRACT

BACKGROUND: During the SARS-CoV-2 pandemic, there was shortage of the standard respiratory protective equipment (RPE). The aim of this study was to develop a procedure to test the performance of alternative RPEs used in the care of COVID-19 patients. METHODS: A laboratory-based test was developed to compare RPEs by total inward leakage (TIL). We used a crossflow nebulizer to produce a jet spray of 1-100 µm water droplets with a fluorescent marker. The RPEs were placed on a dummy head and sprayed at distances of 30 and 60 cm. The outcome was determined as the recovery of the fluorescent marker on a membrane filter placed on the mouth of the dummy head. RESULTS: At 30 cm, a type IIR surgical mask gave a 17.7% lower TIL compared with an FFP2 respirator. At 60 cm, this difference was similar, with a 21.7% lower TIL for the surgical mask compared to the respirator. When adding a face shield, the TIL at 30 cm was further reduced by 9.5% for the respirator and 16.6% in the case of the surgical mask. CONCLUSIONS: A safe, fast and very sensitive test method was developed to assess the effectiveness of RPE by comparison under controlled conditions.


Subject(s)
COVID-19/prevention & control , Infectious Disease Transmission, Patient-to-Professional/prevention & control , Masks/standards , Personal Protective Equipment/standards , Respiratory Protective Devices/standards , Aerosols/adverse effects , Humans , Occupational Exposure/prevention & control , SARS-CoV-2 , Ventilators, Mechanical , Water
11.
Health Secur ; 19(4): 379-385, 2021.
Article in English | MEDLINE | ID: covidwho-1066215

ABSTRACT

National Institute for Occupational Safety and Health (NIOSH)-approved respirators are required by the Occupational Safety and Health Administration (OSHA) when personal respiratory protection is used in US occupational settings. During the COVID-19 pandemic, the demand for NIOSH-approved N95 filtering facepiece respirators overwhelmed the available supply. To supplement the national inventory of N95 respirators, contingency and crisis capacity strategies were implemented and incorporated a component that endorsed the use of non-NIOSH-approved respiratory protective devices that conformed to select international standards. The development and execution of this strategy required the collaborative effort of numerous agencies. The Food and Drug Administration temporarily authorized non-NIOSH-approved international respiratory protective devices through an emergency use authorization, OSHA relaxed their enforcement guidance concerning their use in US workplaces, and NIOSH initiated a supplemental performance assessment process to verify the quality of international devices. NIOSH testing revealed that many of the non-NIOSH-approved respiratory protective devices had filtration efficiencies below 95% and substantial inconsistencies in filtration performance. This article reports the results of the NIOSH testing to date and discusses how it has contributed to continuous improvement of the crisis strategy of temporarily permitting the use of non-NIOSH-approved respirators in US occupational settings during the COVID-19 pandemic.


Subject(s)
COVID-19 , Environmental Health/standards , Filtration/standards , National Institute for Occupational Safety and Health, U.S./standards , Public Health , Respiratory Protective Devices/standards , Filtration/instrumentation , Humans , Internationality , Occupational Exposure/prevention & control , United States
12.
Swiss Med Wkly ; 151: w20459, 2021 01 18.
Article in English | MEDLINE | ID: covidwho-1055197

ABSTRACT

BACKGROUND: SARS-CoV-2 is a respiratory virus. Transmission occurs by droplets, contact and aerosols. In medical settings, filtering facepiece (FFP) respirators are recommended for use by personnel exposed to aerosol-generating procedures. During the COVID-19 pandemic, the demand for FFP respirators exceeded their supply worldwide and low-quality products appeared on the market, potentially putting healthcare workers at risk. AIMS: To raise awareness about variations in quality of imported FFP respirators in Switzerland during the COVID-19 pandemic, to draw attention to the current directives regulating the market launch of FFP respirators in Switzerland, to provide practical support in identifying suspicious products or documents and, finally, to offer strategies aimed at reducing the distribution of low-quality FFP respirators in the future. METHODS: Three Swiss laboratories, Spiez Laboratory and Unisanté in partnership with TOXpro SA individually set up testing procedures to evaluate aerosol penetration and fit testing of FFP respirators imported into Switzerland during COVID-19 pandemic. Additionally, Spiez Laboratory visually inspected the products, examined the certification documents and crosschecked the product information with international databases. RESULTS: Between 31 March and 15 June 2020, 151 FFP respirators were analysed. The initial assessment performed before testing allowed a reduction of up to 35% in the number of FFP respirators sent to Spiez Laboratory for evaluation, for which product information found to be faulty. After filtration efficiency evaluation and fit testing, 52% and 60% of all products tested by Spiez Laboratory and Unisanté-TOXpro SA, respectively, did not meet the minimum performance requirements established independently by the three Swiss laboratories. CONCLUSION: The demand for FFP respirators exceeded the supply capacity from established suppliers of the Swiss market. New production and import channels emerged, as did the number of poor-quality FFP respirators. FFP respirators remaining in stocks should be checked for conformity before being used, or eliminated and replaced if quality does not meet standards.


Subject(s)
COVID-19/prevention & control , N95 Respirators/standards , COVID-19/transmission , Humans , In Vitro Techniques , N95 Respirators/supply & distribution , Product Labeling , Respiratory Protective Devices/standards , Respiratory Protective Devices/supply & distribution , SARS-CoV-2 , Switzerland
15.
J Card Fail ; 27(1): 105-108, 2021 01.
Article in English | MEDLINE | ID: covidwho-963391

ABSTRACT

BACKGROUND: Exercise testing plays an important role in evaluating heart failure prognosis and selecting patients for advanced therapeutic interventions. However, concern for severe acute respiratory syndrome novel coronavirus-2 transmission during exercise testing has markedly curtailed performance of exercise testing during the novel coronavirus disease-2019 pandemic. METHODS AND RESULTS: To examine the feasibility to conducting exercise testing with an in-line filter, 2 healthy volunteer subjects each completed 2 incremental exercise tests, one with discrete stages of increasing resistance and one with a continuous ramp. Each subject performed 1 test with an electrostatic filter in-line with the system measuring gas exchange and air flow, and 1 test without the filter in place. Oxygen uptake and minute ventilation were highly consistent when evaluated with and without use of an electrostatic filter with a >99.9% viral efficiency. CONCLUSIONS: Deployment of a commercially available in-line electrostatic viral filter during cardiopulmonary exercise testing is feasible and provides consistent data compared with testing without a filter.


Subject(s)
COVID-19/epidemiology , COVID-19/prevention & control , Exercise Test/standards , Heart Failure/diagnosis , Heart Failure/epidemiology , Respiratory Protective Devices/standards , Exercise Test/methods , Feasibility Studies , Humans , Male , Oxygen Consumption/physiology , Pandemics , Pulmonary Gas Exchange/physiology , Reproducibility of Results
16.
Rev Sci Instrum ; 91(11): 114101, 2020 Nov 01.
Article in English | MEDLINE | ID: covidwho-951299

ABSTRACT

The SARS-CoV-2 global pandemic has produced widespread shortages of certified air-filtering personal protection equipment and an acute need for rapid evaluation of breathability and filtration efficiency of proposed alternative solutions. Here, we describe experimental efforts to nondestructively quantify three vital characteristics of mask approaches: breathability, material filtration effectiveness, and sensitivity to fit. We focus on protection against aqueous aerosols >0.3 µm using off-the-shelf particle, flow, and pressure sensors, permitting rapid comparative evaluation of these three properties. We present and discuss both the pressure drop and the particle penetration as a function of flow to permit comparison of relative protection for a set of proposed filter and mask designs. The design considerations of the testing apparatus can be reproduced by university laboratories and medical facilities and used for rapid local quality control of respirator masks that are of uncertified origin, monitoring the long-term effects of various disinfection schemes and evaluating improvised products not designed or marketed for filtration.


Subject(s)
COVID-19/prevention & control , Masks , Pandemics/prevention & control , Respiratory Protective Devices , SARS-CoV-2 , Aerosols , Air Microbiology , Air Movements , Air Pressure , COVID-19/transmission , Equipment Design/standards , Face , Filtration/instrumentation , Humans , Masks/standards , Materials Testing/instrumentation , Materials Testing/standards , N95 Respirators/standards , Particle Size , Respiratory Protective Devices/standards
17.
Wound Manag Prev ; 66(11): 13-17, 2020 11.
Article in English | MEDLINE | ID: covidwho-931987

ABSTRACT

At the beginning of the coronavirus disease-19 pandemic, health care staff at a level 1 trauma center in the state of New York experienced facial irritation and skin breakdown under their N95 respirators due to increased and prolonged use. PURPOSE: Members of the Certified Wound and Ostomy Nurse, Nurse Practitioners staff were charged with developing recommendations within 48 hours to help prevent and manage facial skin issues using available products that would not compromise the seal of the respirators. METHOD: With the assistance of a health care safety specialist from the Environmental Health and Safety Department of the hospital, an ambient particle counting device was used to measure the N95 fit factor following application of a liquid skin barrier, transparent film dressing, light silicone-based adhesive dressing, or an extra-thin hydrocolloid dressing on the bridge of the nose and the cheekbones underneath an N95 respirator of 2 hospital staff members who volunteered to test the dressings. RESULTS: All thin dressings tested showed a fit factor over 100, reflecting an effective seal. The highest fit factors were seen with the liquid skin barrier in the 2 volunteers (200 and 198, respectively). Thin dressing usage information was included in the hospital guidelines for N95 respirators and shared with staff. Subsequent feedback suggests that the light silicone-based adhesive dressing and the extra-thin hydrocolloid dressing were preferred. CONCLUSION: Thin dressing use may help reduce skin complications among hospital staff during periods of extended N95 respirator wear time. Because use of the dressings did not result in failure of the quantitative fit test, they were permitted for use by health care staff under their N95 respirators. Studies are needed to help health care facilities optimize N95 respirator use to protect staff from coronavirus disease-19 and respirator-related skin complications while supply shortages remain.


Subject(s)
COVID-19/prevention & control , Hospital Administration , Masks/standards , Respiratory Protective Devices/standards , COVID-19/virology , Humans , Materials Testing , Occupational Exposure/prevention & control , Pandemics , SARS-CoV-2 , Skin/pathology
18.
Occup Med (Lond) ; 70(8): 556-563, 2020 12 12.
Article in English | MEDLINE | ID: covidwho-930045

ABSTRACT

BACKGROUND: Fluid Resistant Surgical Masks have been implemented in UK personal protective equipment (PPE) guidelines for COVID-19 for all care sites that do not include aerosol-generating procedures (AGPs). FFP3 masks are used in AGP areas. Concerns from the ENT and plastic surgery communities out with intensive care units have questioned this policy. Emerging evidence on cough clouds and health care worker deaths has suggested that a review is required. AIMS: To test the efficacy of Fluid Resistant Surgical Mask with and without adaptions for respiratory protection. To test the efficacy of FFP and FFP3 regarding fit testing and usage. METHODS: A smoke chamber test of 5 min to model an 8-h working shift of exposure while wearing UK guideline PPE using an inspiratory breathing mouthpiece under the mask. Photographic data were used for comparison. RESULTS: The Fluid Resistant Surgical Mask gave no protection to inhaled smoke particles. Modifications with tape and three mask layers gave slight benefit but were not considered practical. FFP3 gave complete protection to inhaled smoke but strap tension needs to be 'just right' to prevent facial trauma. Facial barrier creams are an infection risk. CONCLUSIONS: Surgical masks give no protection to respirable particles. Emerging evidence on cough clouds and health care worker deaths suggests the implementation of a precautionary policy of FFP3 for all locations exposed to symptomatic or diagnosed COVID-19 patients. PPE fit testing and usage policy need to improve to include daily buddy checks for FFP3 users.


Subject(s)
Inhalation Exposure/prevention & control , Masks/standards , Occupational Exposure/prevention & control , Respiratory Protective Devices/standards , Smoke/analysis , Aerosols , COVID-19/prevention & control , COVID-19/transmission , Equipment Design , Equipment Safety , Humans , Infectious Disease Transmission, Professional-to-Patient/prevention & control , SARS-CoV-2 , Smoke Inhalation Injury/prevention & control , Ventilators, Mechanical/standards
19.
PLoS One ; 15(11): e0242304, 2020.
Article in English | MEDLINE | ID: covidwho-926880

ABSTRACT

INTRODUCTION: The COVID-19 pandemic has unveiled widespread shortages of personal protective equipment including N95 respirators. Several centers are developing reusable stop-gap respirators as alternatives to disposable N95 respirators during public health emergencies, using techniques such as 3D-printing, silicone moulding and plastic extrusion. Effective sealing of the mask, combined with respiratory filters should achieve 95% or greater filtration of particles less than 1um. Quantitative fit-testing (QNFT) data from these stop-gap devices has not been published to date. Our team developed one such device, the "SSM", and evaluated it using QNFT. METHODS: Device prototypes were iteratively evaluated for comfort, breathability and communication, by team members wearing them for 15-30min. The fit and seal were assessed by positive and negative pressure user seal checks. The final design was then formally tested by QNFT, according to CSA standard Z94.4-18 in 40 volunteer healthcare providers. An overall fit-factor >100 is the passing threshold. Volunteers were also tested by QNFT on disposable N95 masks which had passed qualitative fit testing (QLFT) by institutional Occupational Health and Safety Department. RESULTS: The SSM scored 3.5/5 and 4/5 for comfort and breathability. The median overall harmonic mean fit-factors of disposable N95 and SSM were 137.9 and 6316.7 respectively. SSM scored significantly higher than disposable respirators in fit-test runs and overall fit-factors (p <0.0001). Overall passing rates in disposable and SSM respirators on QNFT were 65% and 100%. During dynamic runs, passing rates in disposable and SSM respirators were 68.1% and 99.4%; harmonic means were 73.7 and 1643. CONCLUSIONS: We present the design and validation of a reusable N95 stop-gap filtering facepiece respirator that can match existent commercial respirators. This sets a precedence for adoption of novel stop-gap N95 respirators in emergency situations.


Subject(s)
Coronavirus Infections/prevention & control , Equipment Design , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Respiratory Protective Devices/standards , Adult , Betacoronavirus , COVID-19 , Equipment Failure Analysis , Equipment Reuse , Female , Filtration , Humans , Male , Middle Aged , SARS-CoV-2
20.
Otolaryngol Head Neck Surg ; 163(1): 98-103, 2020 07.
Article in English | MEDLINE | ID: covidwho-913959

ABSTRACT

The correct selection and utilization of respiratory personal protective equipment is of the utmost importance in the current COVID-19 pandemic. This is especially true for health care workers exposed to high-risk aerosol-generating procedures, including otolaryngologists, ophthalmologists, neurosurgeons, maxillofacial surgeons, and laparoscopic surgeons. This communication provides a review of approved forms of respiratory protection and compares their characteristics, including surgical masks, N95 respirator, elastomeric respirators, powered air-purifying respirators, and controlled air-purifying respirators. For standard airborne precautions, N95 respirator are appropriate for respiratory protection. However, high-risk aerosol-generating procedures may create aerosolization of high viral loads that represent increased risk to health care workers. In these situations, enhanced respiratory protection with filters certified as 99, 100, or HEPA (high-efficiency particulate air) may be appropriate.


Subject(s)
Aerosols/administration & dosage , Betacoronavirus , Coronavirus Infections/epidemiology , Disease Transmission, Infectious/prevention & control , Pandemics , Personal Protective Equipment/standards , Pneumonia, Viral/epidemiology , Respiratory Protective Devices/standards , COVID-19 , Coronavirus Infections/transmission , Humans , Pneumonia, Viral/transmission , Risk Factors , SARS-CoV-2
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