The Filtration Efficiency of Single-Layer Textiles for Respiratory protection

2021 ◽  
Vol 3 (2) ◽  
pp. 1-12
Author(s):  
Behnam Pourdeyhimi ◽  
Simon Schick ◽  
Robert Groten
Keyword(s):  
Particle Size ◽  
Single Layer ◽  
Face Mask ◽  
Filtration Efficiency ◽  
Respiratory Protection ◽  
Test Protocol ◽  
Astm Standard ◽  
The Face

Due to the increasing number of corona cases and the face mask industry's associated bottleneck, this work focuses on the various single-layer textiles used as cloth masks. The purpose of this work is to test ten different single-layer textiles for their suitability as face masks. All tests in this work were carried out based on the ASTM F2299 and the new ASTM Standard for barrier masks (3502-21). The new standard offers a more precisely defined test protocol and is consistent with how respirators are tested. The results show that only one of the ten textiles tested meets the ASTM requirements for a barrier mask. We also include data for ASTM F2299 and report the results for unneutralized challenge particles at various face velocities for the same single-layer textiles. These results are different from those of the ASTM 3502 because the particle size and the procedure used are different.  Under ASTM 3502, the resistance values ​​are significantly higher, and the efficiency values ​​are significantly lower than those reported by using the ASTM F2299.

scholarly journals Filtration efficiency of face masks and veils as protective measures during COVID-19 pandemic

2021 ◽  
Author(s):  
Khaled S. Al-Hadyan ◽  
◽  
Ghazi A. Alsbeih Alsbeih ◽  
Najla M. Al-Harbi ◽  
Sara S. Bin Judia ◽  
...  
Keyword(s):  
Particle Size ◽  
Control Measure ◽  
Filtration Efficiency ◽  
Experimental Conditions ◽  
Surgical Masks ◽  
Significant Difference ◽  
Comparable Performance ◽  
The Face ◽  
3D Printed ◽  
The Mean

Wearing face masks have been implemented as a public and personal health control measure against the spread of coronavirus disease (COVID-19). However, the protection level of nonmedical face masks, such as women face veils, is still uncertain. This study aimed to assess the filtration efficiency (FE; percentage of particles retained by a mask) of different types of medical masks (either as sealed or unsealed, single or doubled), non-medical masks (cloth masks) and face veils. FE of face masks was evaluated using an in-house 3D-printed air duct connected to the Aerotrak particle counter with a capability of counting particle sizes of 0.3, 0.5, 0.7, 1, 2 and 5 μm. A set of 10 earloop surgical masks,10 tie-on surgical masks, 3 triple-layers reusable cloth masks and 3 types (short, medium and long) of traditional face veils were included in the study. The unsealed surgical masks showed intermediate FE (36.54-80.58%), with no observed differences between tie-on and earloop or single and doubled masks. For each mask type, the mean FE values of sealed surgical masks (FE≥99.16%) was significantly higher (P<0.001) than the unsealed ones (FE≤80.58%). No significant difference was observed in the mean FE values between unsealed surgical masks and either cloth masks (FE=23.19-75.35%, P=0.26) or face veils (FE=19.10- 70.68%, P=0.14). However, a mockup experiment showed that wearing a surgical mask under the face veil significantly improve the FE (33.73-79.18%; P<0.001). We conclude that besides sealed surgical masks that ensure optimal filtration under the experimental conditions, the unsealed surgical and cloth masks and face veils showed comparable performance and acceptable protection at 5 μm particle size, which is the most relevant particle size associated with COVID-19 infectious droplets. Wearing a surgical mask under the face veil significantly improves the FE compared to wearing a face veil alone.

scholarly journals Comparison of Bacterial Filtration Efficiency vs. Particle Filtration Efficiency to Assess the Performance of Non-Medical Face Masks in the Emergency Context of COVID-19 Pandemic

2021 ◽  
Author(s):  
Henrietta Essie Whyte ◽  
Yoann Montigaud ◽  
Estelle Audoux ◽  
Paul Verhoeven ◽  
Amélie Prier ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Filtration Efficiency ◽  
Reference Test ◽  
Test Protocol ◽  
Particle Filtration ◽  
Different Types ◽  
The Difference ◽  
Biological Particle ◽  
Specific Expertise

Abstract As a result of the current COVID-19 pandemic, the use of facemasks has become commonplace. The performance of medical facemasks is assessed using Bacterial Filtration Efficiency (BFE) tests. However, as BFE tests, require specific expertise and equipment and are time-consuming, the performance of non-medical facemasks is assessed with non-biological Particle Filtration Efficiency (PFE) tests which are comparatively easier to implement. It is necessary to better understand the possible correlations between BFE and PFE to be able to compare the performances of the different types of masks (medical vs. non-medical). In this study BFE results obtained in accordance with the standard EN 14683 are compared to the results of PFE from a reference test protocol defined by AFNOR SPEC S76-001 with the aim to determine if BFE could be predicted from PFE. Our results showed a correlation between PFE and BFE. It was also observed that PFE values were higher than BFE and this was attributed to the difference in particle size distribution considered for efficiency calculation. In order to properly compare these test protocols for a better deduction, it would be interesting to compare the filtration efficiency for a similar granulometric range.

scholarly journals Making cotton face masks extra-protective by use of impervious cloth as the front layer to restrict flow of aerosols and droplets

2020 ◽  
Author(s):  
Priyanka L Shahane-Kapse ◽  
Moreshwar R Shende ◽  
Sumit Kar ◽  
Pradeep Deshmukh ◽  
Dhiraj Bhandari ◽  
...  
Keyword(s):  
Single Layer ◽  
Middle Layer ◽  
Face Mask ◽  
The Other ◽  
Outer Side ◽  
Carbol Fuchsin ◽  
Triple Layer ◽  
Impervious Layer ◽  
Surgical Masks ◽  
The Face

Introduction: One of the important measures to prevent spread of COVID-19 in community is use of face mask. Though the debate is going on regarding the airborne transmission of SARS-CoV-2 it makes reasonable point for universal use of face masks. A large variety of face masks are available in the market or people can make their own using household items. The efficacy of masks depends upon the type of cloth and number of layers of the cloth. Material and methods: We have created an innovative mask with two layers of cotton and an impervious layer. The impervious layer made from polypropylene coated with polyurethane was applied on the outer side in the middle half of the mask in front of mouth and nose. The efficacy of this test mask was measured against N95FFR (reference standard), triple layer surgical masks and single layer cotton mask. A manikin was used wearing these masks/respirator and aerosols/droplets of diluted red colored carbol fuchsin and fluorescent Auramine O were sprayed from distance of 1m and 2m. We also tested use of face shield. Both macroscopic and microscopic examination of the dissected masks and respirator was performed. Results: The N95FFR was able to block the aerosols/droplets by its front layer. One triple layer surgical mask showed microscopic presence of stain in its innermost layer while the other blocked it with middle layer. The single layer cotton mask was not able to protect as we observed stain on the face itself. The test mask blocked most of the stain on impervious layer and also on the front cotton layer on lateral sides, where impervious layer was absent. When fluorescent stain was used, ultraviolet examination demonstrated that the whole area covered by test mask was clean while the other non covered area was fluorescent. Conclusion: We believe that our innovation can be used in the community as well as in general areas of the hospital like, offices, labs, etc. and can be a better alternative to single use triple layer surgical masks. Further testing may be done by other organizations to rule out bias in our study.

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.

Graphene versus coronavirus: A study of the graphene properties that can help to combat coronavirus

Coronaviruses ◽  
2021 ◽  
Vol 02 ◽  
Author(s):  
T. Guerra ◽  
I. O. Assis ◽  
A. B. Guerra
Keyword(s):  
Water Molecule ◽  
Graphene Sheet ◽  
Density Functional ◽  
Single Layer ◽  
Face Mask ◽  
Spatial Dimension ◽  
Biological Phenomena ◽  
High Elasticity ◽  
The Face ◽  
Novel Coronavirus

: New and fascinating physical, chemical and biological phenomena arise in ultra-small materials, such as graphene. Graphene is a single layer formed only for carbon atoms, super-strong, 200 times stronger than steel and as much as 6 times lighter. It also has a high elasticity and density. Furthermore, it seems to be impermeable to almost everything, but it allows the passage of water and air. Due to its versatility, modern and urgent applications arise every day, one of the most necessary, currently, is the control of severe acute respiratory syndrome coronavirus 2 (SARS-CoV2), the virus responsible for the novel coronavirus disease (COVID-19), which has dimensions around 100 nm and has caused a worldwide public health emergency. Different ways to prevent coronavirus contagion has been proposed and one of them is through the use of masks. Here, we investigated some properties of graphene that can help combat COVID-19. A scale appropriate for comparison shows that the spatial dimension of a virus is much larger than the graphene sheet, making it a great candidate for manufacturing face masks, filters and respirators. We also make use of first-principles calculations, based on the density functional theory (DFT), to investigate the interaction between graphene and a water molecule. We observed that the water molecule undergoes a repulsion force when it is very close to the graphene sheet. The hydrophobicity of graphene can be important to prevent the face mask that doesn’t get wet when you breathe with it.

scholarly journals Ability of fabric face mask materials to filter ultrafine particles at coughing velocity

BMJ Open ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. e039424 ◽  
Author(s):  
Eugenia O'Kelly ◽  
Sophia Pirog ◽  
James Ward ◽  
P John Clarkson
Keyword(s):  
Ultrafine Particles ◽  
Single Layer ◽  
Face Mask ◽  
Filtration Efficiency ◽  
Adult Human ◽  
Air Concentrations

ObjectiveWe examined the ability of fabrics which might be used to create home-made face masks to filter out ultrafine (0.02–0.1 µm) particles at the velocity of adult human coughing.MethodsTwenty commonly available fabrics and materials were evaluated for their ability to reduce air concentrations of ultrafine particles at coughing face velocities. Further assessment was made on the filtration ability of selected fabrics while damp and of fabric combinations which might be used to construct home-made masks.ResultsSingle fabric layers blocked a range of ultrafine particles. When fabrics were layered, a higher percentage of ultrafine particles were filtered. The average filtration efficiency of single layer fabrics and of layered combination was found to be 35% and 45%, respectively. Non-woven fusible interfacing, when combined with other fabrics, could add up to 11% additional filtration efficiency. However, fabric and fabric combinations were more difficult to breathe through than N95 masks.ConclusionsThe current coronavirus pandemic has left many communities without access to N95 face masks. Our findings suggest that face masks made from layered common fabric can help filter ultrafine particles and provide some protection for the wearer when commercial face masks are unavailable.

scholarly journals Efficacy of face masks, neck gaiters and face shields for reducing the expulsion of simulated cough-generated aerosols

2020 ◽  
Author(s):  
William G. Lindsley ◽  
Francoise M. Blachere ◽  
Brandon F. Law ◽  
Donald H. Beezhold ◽  
John D. Noti
Keyword(s):  
Double Layer ◽  
Aerosol Particles ◽  
Single Layer ◽  
Face Mask ◽  
Cotton Cloth ◽  
Source Control ◽  
The Face ◽  
Community Transmission ◽  
Small Aerosol ◽  
Control Devices

AbstractFace masks are recommended to reduce community transmission of SARS-CoV-2. One of the primary benefits of face masks and other coverings is as source control devices to reduce the expulsion of respiratory aerosols during coughing, breathing, and speaking. Face shields and neck gaiters have been proposed as an alternative to face masks, but information about face shields and neck gaiters as source control devices is limited. We used a cough aerosol simulator with a pliable skin headform to propel small aerosol particles (0 to 7 µm) into different face coverings. An N95 respirator blocked 99% of the cough aerosol, a medical grade procedure mask blocked 59%, a 3-ply cotton cloth face mask blocked 51%, and a polyester neck gaiter blocked 47% as a single layer and 60% when folded into a double layer. In contrast, the face shield blocked 2% of the cough aerosol. Our results suggest that face masks and neck gaiters are preferable to face shields as source control devices for cough aerosols.

scholarly journals Effectiveness of Different Cellulose-Based Filtration Materials against Inhalation of SARS-CoV-2-Like Particles

2021 ◽  
Vol 1 (2) ◽  
pp. 57-66
Author(s):  
Alyne R. de Araújo ◽  
Lívio C. C. Nunes ◽  
Karla C. B. F. Oliveira ◽  
Maria G. F. M. Carvalho ◽  
Juliana C. Cardoso ◽  
...  
Keyword(s):  
Low Cost ◽  
Filter Material ◽  
Face Mask ◽  
Filtration Efficiency ◽  
Testing Time ◽  
Respiratory Protection ◽  
Health Crisis ◽  
The Public ◽  
Public Health Crisis ◽  
Retention Testing

The respiratory protection equipment (RPE) used by health professionals consists of an essential device to prevent infectious diseases, especially those caused by biological agents such as the coronavirus (SARS-CoV-2). The current epidemiological panorama is worrying, and the context of creation and production of the mask has emerged as an alternative to RPE to face the public health crisis worldwide. The aim of this work is to present a low-cost alternative as an FFP2-like filter for a reusable respirator face mask. This study presents the comparison of different cellulose-based filtering materials performed by retention testing, time saturation testing, aerosol penetration testing, nanoparticle (~140 nm) filtration testing, bacterial filtration efficiency (BFE), analysis of material morphology and usability. The reusable respirator face mask used in this study is an open-source innovation, using 3D printing. Cotton disc proved to be the best filter material for the reusable mask, with satisfactory results and a performance similar to that shown by the N95-type mask. The cotton disc ensured effectiveness over 6 h of use, and after that, the reusable respirator face mask (here, Delfi-TRON®) needed to be sanitized and replenished with a new cotton disc. Upon preliminary analyses of filtration efficiency, the selected filter was shown to be a low-cost biodegradable and biocompatible alternative.

scholarly journals Efficacy of face-masks used in Uganda: a laboratory-based inquiry during the COVID-19 pandemic

2020 ◽  
Author(s):  
Gerald Mboowa ◽  
Derrick Semugenze ◽  
Hellen Nakabuye ◽  
Douglas Bulafu ◽  
Dickson Aruhomukama
Keyword(s):  
High Risk ◽  
Risk Groups ◽  
Face Mask ◽  
Descriptive Study ◽  
Filtration Efficiency ◽  
Middle Income ◽  
Different Types ◽  
The Face ◽  
Restricted Use ◽  
Low And Middle Income

Background With shortages of face-masks continuing to be reported worldwide, critical questions like whether or not there is an adequate alternative to commercially manufactured face-masks continue to linger especially in low- and middle- income settings. This study aimed at addressing this through testing and comparing various materials and forms of face-masks for filtration efficiency, breathability, microbial cleanliness, distance-dependent fitness, and re-usability of different face-masks procured from face-mask vendors in Kampala, Uganda. Methods This was a laboratory-based descriptive study that applied new protocols and already existing protocols with substantive modifications to ten different types of face-mask types each in quadruplicate to achieve each specified aim. Results Surgical face-masks had better filtration efficiency, distance-dependent fitness and breathability compared to other face-masks tested. Decontamination of these face-masks with 70% ethanol negatively affected their efficacy. Locally-made double layered face-masks had better: filtration efficiency, distance-dependent fitness and breathability compared to other locally-made cloth face-masks, and re-usability compared to all the face-mask types that had been tested. Discussion/conclusions Locally-made double layered cloth face-masks could serve as alternative face-masks especially for populations in low- and middle- income settings like Uganda while allowing restricted use of surgical face-masks and other respirators like the KN95 to high-risk groups only.

scholarly journals The use of the respiratory protective devices by the population during the COVID-19 pandemic

2021 ◽  
Vol 65 (6) ◽  
pp. 527-532
Author(s):  
Ekaterina A. Shashina ◽  
Denis V. Shcherbakov ◽  
Tatiana S. Isiutina-Fedotkova ◽  
Valentina V. Makarova ◽  
Vitaly A. Sukhov ◽  
...  
Keyword(s):  
Face Mask ◽  
Grocery Stores ◽  
Protective Equipment ◽  
Respiratory Protection ◽  
Protective Devices ◽  
Different Types ◽  
Respiratory Protective Devices ◽  
The Face ◽  
Almost All ◽  
Spread Of Infection

Introduction. Wearing a face mask is an important measure against spread of infection during the COVID-19 pandemic. The purpose of the study was to analyze various aspects of the face masks use by the population during the pandemic. The questioner was used. Results. Almost all respondents (96.4%) wore respiratory protective devices during the pandemic; 91.4% respondents worn face masks visiting grocery stores, pharmacies and medical organizations; 64.0% - visiting non-food trade facilities; 76.9% - travelling by surface transport, and 76.1% - being on the subway. Different types of face masks were used, 93.3% of respondents used disposable medical mask, 25.4% - reusable cloth masks. However, only 44.8% of respondents indicated that their protective equipment was made of non-woven material; 26.1% did not know how many layers their protective equipment contained; about a third of respondents (20.1% - 30.21%) were not able to assess the effectiveness of different types of respiratory protection. A third of the respondents (33.6%) wore a disposable medical mask for 2 hours, 35.2% - more than 2 hours in one day, 28.0% - for several days. Conclusions. Most of the respondents wore the face mask. Disposable medical masks were most commonly used. Requirements for the duration of wearing of face masks were met by about third of the respondents, for the handling - half of the respondents. Spontaneous choice of face mask by respondents confirms the importance of the development of hygiene guideline for choosing the most effective respiratory protection.

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