scholarly journals Assessment of Fabric Masks as Alternatives to Standard Surgical Masks in Terms of Particle Filtration Efficiency

2020 ◽  
Author(s):  
Amy Mueller ◽  
Loretta Fernandez
Keyword(s):  
Health Care Providers ◽  
Ambient Air ◽  
Filtration Efficiency ◽  
Airborne Particles ◽  
Particle Removal ◽  
Breathing Zone ◽  
Care Providers ◽  
Particle Filtration ◽  
Surgical Masks ◽  
Mask Design

AbstractIn response to the critical shortage of medical masks resulting from the COVID-19 pandemic, large portions of the population are mobilizing to produce cloth masks using locally-sourced fabrics, however the efficacy of these masks as a means of protecting the wearer from airborne particles carrying virus is not well known. Further, existing protocols are designed for testing the fit and performance N95 respirators and tight-fitting facemasks rather than the relatively more loose-fitting surgical mask style most cloth masks follow. In this study tools and methods typically used to assess tight-fitting facemasks were modified to assess the efficacy of community-produced fabric and commercially-produced surgical masks in terms of protecting the wearer from airborne particles that may be carrying virus. Two TSI PortaCount (model 8028) instruments were operated concurrently to collect particle counts (particles/cm3) in size range 0.02 to >1 µm from ambient air and air just inside the breathing zone of the mask (1 measurement per second, evaluation period of 1 minute per test). Percent particle removal was determined for ten home-made, fabric masks of different designs, with and without filter layers, as well as three commercially-produced surgical-type masks. N95 masks were used to validate the method, and a 3M model 1826 surgical mask was used as a baseline for comparison of other masks of this style. Home-made masks worn as designed always had lower particle removal rates than the 3M masks, achieving between 38% and 96% of this baseline. As has been previously observed by Cooper et al. (1983), adding a layer of nylon stocking over the masks minimized the flow of air around the edges of the masks and improved particle filtration efficiency for all masks, including all commercial products tested. Use of a nylon stocking overlayer brought the particle filtration efficiency for five of the ten fabric masks above the 3M surgical mask baseline. This rapid testing method (<2 hours per mask design) provides a holistic evaluation of mask particle removal efficacy (material, design, and fit), and use of this method for testing a wider range of mask materials and designs will provide the public and health care providers with information needed to optimize health protection given resources at hand.

Microwave structured polyamide-6 nanofiber/net membrane with embedded poly(m-phenylene isophthalamide) staple fibers for effective ultrafine particle filtration

2016 ◽  
Vol 4 (16) ◽  
pp. 6149-6157 ◽  
Author(s):  
Shichao Zhang ◽  
Hui Liu ◽  
Jianyong Yu ◽  
Wenjing Luo ◽  
Bin Ding
Keyword(s):  
Pressure Drop ◽  
Ultrafine Particle ◽  
Polyamide 6 ◽  
Low Pressure ◽  
Filtration Efficiency ◽  
Airborne Particles ◽  
Particle Filtration

Microwave structured PA-6/PMIA NFN membrane can filter airborne particles with high filtration efficiency, low pressure drop, and large dust-holding capacity.

scholarly journals A highly efficient cloth facemask

2021 ◽  
Author(s):  
Christopher Cappa ◽  
The San Francisco Opera Costume Department ◽  
William Ristenpart ◽  
Santiago Barreda ◽  
Nicole Bouvier ◽  
...  
Keyword(s):  
High Efficiency ◽  
Separation Distance ◽  
Filtration Efficiency ◽  
Ambient Aerosols ◽  
The Public ◽  
Professional Singers ◽  
Surgical Masks ◽  
Mask Design ◽  
N95 Respirators ◽  
Better Than

Abstract Wearing masks and face coverings helps reduce transmission of respiratory diseases. Much prior research on mask filtration efficiency has focused on fabric type, with less consideration given to mask design and shape. Here, we present evidence that increasing the mouth-mask separation distance engenders an increase in the mask-fabric filtration efficiency towards expiratory aerosols emitted via vocalization, which we attribute to a decrease in the expiratory jet velocity and expansion of the breath-mask contact area. We further assess the performance of a new reusable cloth facemask design, originally made for, but not exclusive to, professional singers and having a large mouth-mask separation distance. With proper fitting, these masks achieve overall filtering efficiencies of >93% for both exhaled expiratory aerosols >0.5 microns in diameter from singing and speaking and for inhaled ambient aerosols, better than surgical masks and approaching N95 respirators. Air exchange between the mask deadspace and the ambient environment limits the extent of CO2 buildup and in inhaled air and maintains O2 levels near ambient. The mask design also provides for less inhibited mouth and jaw movement and lower relative humidity, suggesting it may provide a more palatable, high-efficiency alternative to medical-grade masks for the public.

Surgical Mask Particle Filtration Efficiency (PFE)

2020 ◽  
Vol 2 (3) ◽  
pp. 1-11
Author(s):  
Behnam Pourdeyhimi
Keyword(s):  
Test Methods ◽  
Filtration Efficiency ◽  
Standard Test ◽  
Regulatory Agencies ◽  
Guidance Document ◽  
Test Procedures ◽  
Particle Filtration ◽  
Fda Guidance ◽  
Surgical Masks

The particle filtration efficiency (PFE) of surgical (procedure) masks is a key differentiator of its classification and therefore, its use by healthcare workers.  Surgical masks are regulated by the Food and Drug Administration (FDA).  The FDA Guidance document has adopted a number of ASTM standards for establishing the criteria for the classification of masks.  ASTM F2299 is recommended for the measurement of PFE with minor modifications. Both ASTM F2299 and the FDA Guidance Document fail however to establish standard test procedures and therefore, it is possible to attain diverging results.  This creates a major problem in one’s ability to be able to relate the measured performance across different masks on the market.  In this paper, we outline the deficiencies of these test methods and discuss the challenges that need to be addressed by FDA and other regulatory agencies.

Quick laboratory methodology for determining the particle filtration efficiency of face masks/respirators in the wake of COVID-19 pandemic

2020 ◽  
pp. 152808372097508
Author(s):  
Manish Joshi ◽  
Arshad Khan ◽  
BK Sapra
Keyword(s):  
Pressure Drop ◽  
Filter Material ◽  
Filtration Efficiency ◽  
Capture Efficiency ◽  
Particle Capture ◽  
Particle Filtration ◽  
Mask Design ◽  
Mask Material ◽  
Present Context ◽  
The Times

Recent crisis in the form of COVID-19 has rendered wearing of mask mandatory for patients, health care workers and members of public worldwide. This has caused a sudden shift of focus on availability, effectiveness, re-use and development of face masks/respirators. In the current pandemic situation, the shortage of masks has also led to rethinking on strategies of reuse of masks after due sterilization. This work discusses a quick laboratory methodology to test/determine the particle filtration efficiency of face masks/respirators. The testing parameters include the particle capture efficiency of the mask material/full mask, pressure drop and the fit factor. Two different, simple, make-shift set-ups have been adopted for the present context. The first is used to measure the intrinsic particle capture efficiency and pressure drop of the filter material and the second as a ‘full mask sampler’ to assess the leakages through seams and joints of the mask. Experiments conducted with atomized NaCl test particles on three types of mask viz. commercial N-95 respirator, surgical mask and cloth mask have been used for evolving the methodology. The differences in terms of capture efficiency of aerosol particles for the filter material and for the full mask in face fix/sealed fixture have been linked to improvement of the mask design in development phase. This paper hopes to provide a crucial laboratory link between the mask developers and the certification agencies in the times of urgency. Needless to mention that commercialization of the same is subject to certification from authorized agencies, following standard procedures.

scholarly journals Expiratory aerosol particle escape from surgical masks due to imperfect sealing

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christopher D. Cappa ◽  
Sima Asadi ◽  
Santiago Barreda ◽  
Anthony S. Wexler ◽  
Nicole M. Bouvier ◽  
...  
Keyword(s):  
Aerosol Particle ◽  
Aerosol Particles ◽  
Filtration Efficiency ◽  
Particle Removal ◽  
Emission Rates ◽  
Leakage Flows ◽  
Surgical Masks ◽  
Overall Efficiency ◽  
Substantial Control ◽  
Estimate Flow

AbstractWearing surgical masks or other similar face coverings can reduce the emission of expiratory particles produced via breathing, talking, coughing, or sneezing. Although it is well established that some fraction of the expiratory airflow leaks around the edges of the mask, it is unclear how these leakage airflows affect the overall efficiency with which masks block emission of expiratory aerosol particles. Here, we show experimentally that the aerosol particle concentrations in the leakage airflows around a surgical mask are reduced compared to no mask wearing, with the magnitude of reduction dependent on the direction of escape (out the top, the sides, or the bottom). Because the actual leakage flowrate in each direction is difficult to measure, we use a Monte Carlo approach to estimate flow-corrected particle emission rates for particles having diameters in the range 0.5–20 μm. in all orientations. From these, we derive a flow-weighted overall number-based particle removal efficiency for the mask. The overall mask efficiency, accounting both for air that passes through the mask and for leakage flows, is reduced compared to the through-mask filtration efficiency, from 93 to 70% for talking, but from only 94–90% for coughing. These results demonstrate that leakage flows due to imperfect sealing do decrease mask efficiencies for reducing emission of expiratory particles, but even with such leakage surgical masks provide substantial control.

scholarly journals Comparative Study upon using Sanitizers and Personal Protective Equipment during COVID-19 Pandemic between Saudi and Egyptian Health Care Providers

2021 ◽  
pp. 61-73
Author(s):  
Madiha Rabie Mahmoud ◽  
Jomana Adel Jasim Almuaili ◽  
Safaa Malek Shaheen ◽  
Manal Nasser Zaben Alatifi ◽  
Osama Gad Abdelaziz ◽  
...  
Keyword(s):  
Adverse Reaction ◽  
Health Care Providers ◽  
Personal Protective Equipment ◽  
Protective Equipment ◽  
Care Providers ◽  
Nasal Bridge ◽  
Skin Reactions ◽  
Surgical Masks ◽  
Long Time ◽  
Structured Questionnaire

Wearing masks were effective in reducing the probability of infection with COVID-19, but wearing them for long time cause many problems. This paper was aimed to compare between Saudi and Egyptian HCWs upon using sanitizers and personal protective equipment (PPE) during COVID-19 pandemic. Data was collected through a well-structured questionnaire, among Saudi HCWs (online) and Egyptian HCWs through paper questionnaire interview. The questionnaire consists of 23 questions about Socio-demographic, types of masks, gloves and sanitizers they used during their works. It includes the adverse skin reactions on hands and face upon using PPE for long periods during COVID 19 pandemic. Our results revealed that most of Saudi & Egyptian HCWs wearing surgical masks (57.8% & 63.6%), > N95 (12.9% &18.2%), using latex surgical gloves (44.9% & 56.8%), > plastic gloves (11.1% &18.2%) respectively. The most affected area from wearing PPE are hands (49.8% & 54.5%) followed by Auricular area (44% & 40.9%), nasal bridge (28.9% & 22.7%), check (16.9% & 13.6%), whole face (15.6% & 25%) among Saudi & Egyptian HCWs respectively. About 70% of Egyptian HCWs from our participants used alcohol 70% in form of gel as sanitizer which was significantly higher than Saudi HCWs (59.1%). While no significant differences were found from using other sanitizers such as liquid alcohol 70% or Dettol. The most adverse reaction due to using sanitizers was skin dryness (55.1% & 63.6%) among Saudi & Egyptian HCWs respectively. We can conclude that significant increase was found among HCWs in Egypt either in wearing surgical and N95 masks or in wearing surgical and plastic gloves when compared to Saudi HCWs. According to the side effects on hands and face due to wearing PPE among HCWs either from KSA or Egypt, there were some variations by increase or decrease in the percentages. The most adverse reaction due to using sanitizers (specially alcohol 70% in form of gel) was skin dryness.

scholarly journals An improved and highly efficient geometry for facemasks

2021 ◽  
Author(s):  
Christopher Cappa ◽  
William Ristenpart ◽  
Santiago Barreda ◽  
Nicole Bouvier ◽  
Anthony Wexler ◽  
...  
Keyword(s):  
High Efficiency ◽  
Separation Distance ◽  
Filtration Efficiency ◽  
Ambient Aerosols ◽  
The Public ◽  
Professional Singers ◽  
Surgical Masks ◽  
Mask Design ◽  
N95 Respirators ◽  
Better Than

Abstract Wearing masks and face coverings helps reduce transmission of respiratory diseases. Much prior research on mask filtration efficiency has focused on fabric type, with little consideration given to mask geometry. Here, we present evidence that increasing the mouth-mask separation distance engenders an increase in the mask-fabric filtration efficiency towards expiratory aerosols emitted via vocalization, which we attribute to a decrease in the expiratory jet velocity. We further assess the performance of a new reusable cloth facemask design, originally made for professional singers and having a large mouth-mask separation distance. With proper fitting, these masks achieve overall filtering efficiencies of >93% for both exhaled expiratory aerosols from singing and speaking and for inhaled ambient aerosols, better than surgical masks and approaching N95 respirators. The mask design also provides for less inhibited mouth and jaw movement, suggesting it may provide a more palatable, high-efficiency alternative to medical-grade masks for the public.

scholarly journals Live Scoping Review of N95 and Surgical Facemask Decontamination and Reuse: A Scoping Review Protocol

2020 ◽  
Author(s):  
Katie O'Hearn ◽  
Anirudh Agarwal ◽  
Karen Choong ◽  
Shira Gertsman ◽  
Nassr Nama ◽  
...  
Keyword(s):  
Health Care ◽  
Health Care Providers ◽  
Systematic Reviews ◽  
Scoping Review ◽  
Potential Method ◽  
Original Research ◽  
Care Providers ◽  
Term Care ◽  
Surgical Masks ◽  
Open Access Database

During the COVID-19 pandemic, a shortage of personal protective equipment (PPE), namely surgical masks, N95 masks, and gowns, has been experienced by some hospitals and could be expected in others due to a rapidly increased need. The Centres for Disease Control and Prevention (CDC) specifically recommends N95 filtering facepiece respirators (FFRs) for healthcare workers who are interacting with patients with COVID-19 under aerosol precautions, and when performing aerosol generating medical procedures. In contrast, surgical masks have much broader use and are recommended for use by health care providers to protect against the risk of droplet transmission in inpatient healthcare settings and outpatient settings (e.g. COVID-19 assessment centres, long-term care facilities, and community care settings). One potential method of addressing the shortage and ensuring adequate protection for health care workers in accordance with the above recommendations would be to decontaminate and reuse N95 FFRs and surgical masks. Our group recently conducted a series of systematic reviews to synthesize the existing literature on N95 and surgical mask decontamination. However, literature in this area is rapidly evolving and these systematic reviews will require updates in order to provide clinicians, hospital administrators, and public health officials with the most up-to-date and comprehensive information available. The purpose of this living scoping review is to identify all original research on N95 and surgical mask decontamination and reuse, and to build an open-access database of the existing literature.

scholarly journals Health Effects of Air Pollution in Canada: Expert Panel Findings for The Canadian Smog Advisory Program

1995 ◽  
Vol 2 (3) ◽  
pp. 155-160
Author(s):  
David M Stieb ◽  
L David Pengelly ◽  
Nina Arron ◽  
S Martin Taylor ◽  
Mark E Raizenne
Keyword(s):  
Air Pollution ◽  
Health Effects ◽  
Health Care Providers ◽  
Hospital Admissions ◽  
Ground Level ◽  
Ambient Air ◽  
Health Messages ◽  
Airway Hyperreactivity ◽  
Care Providers ◽  
Advisory Program

OBJECTIVE: To review the evidence on health effects of air pollution for the Canadian Smog Advisory Program.METHODS: Evidence was reviewed by two expert panels, who were asked to define the health effects expected at levels of exposure given by the National Ambient Air Quality Objectives, to examine a variety of issues related to communicating with the public about environmental health risks, and to draft health messages for the advisory program.RESULTS: The panels concluded that health effects of ground-level ozone at levels that occur in Canada include pulmonary inflammation, pulmonary function decrements, airway hyperreactivity, respiratory symptoms, possible increased medication use and physician/emergency room visits among individuals with heart or lung disease, reduced exercise capacity, increased hospital admissions and possible increased mortality. Similar effects were felt to occur in association with airborne particles, with the exception of inflammatory changes, and with the addition of increased school absenteeism. Poor data on individual exposure were identified as a limitation of studies on hospital admissions and mortality.RECOMMENDATIONS: The panels identified the need to reflect the evidence accurately without unduly raising public concern and recommended that advisory health messages identify expected health effects, while health care providers could more appropriately recommend protective actions to individuals. Supplementary educational strategies and evaluation of the advisory program were also recommended.

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