scholarly journals Material Suitability Testing for Nonmedical Grade Community Face Masks to Decrease Viral Transmission During a Pandemic

2020 ◽  
pp. 1-7
Author(s):  
Csanad Varallyay ◽  
Ningcheng (Peter) Li ◽  
Brendan Case ◽  
Bryan Wolf
Keyword(s):  
Pressure Gauge ◽  
Filtration Efficiency ◽  
Viral Transmission ◽  
Airflow Resistance ◽  
Nonwoven Fabrics ◽  
Filtration Performance ◽  
Surgical Masks ◽  
Fit Testing ◽  
Control And Prevention ◽  
Fabric Material

Abstract Objectives: Cloth face covering has been recommended by the Centers for Disease Control and Prevention to decrease community viral transmission. This study aims to determine the filtration efficiency and airflow resistance of common household materials available for homemade mask production by comparing numbers of fabrics, various layers, and manipulation. Methods: Common household woven, knitted, and nonwoven fabrics were tested for filtration efficiency using a fit testing setup and airflow resistance with pressure gauge setup. Three different levels of layering (1, 2, and 4) were tested. Some fabric material was further tested after washing and drying. Filtration performance, the area under the fitted curve comparing airflow resistance and filtration efficiency, was calculated for each fabric material and compared. Results: Layering increased filtration efficiency and airflow resistance (P < 0.0001 and P < 0.01, respectively). Polyester felt demonstrated the highest filtration performance index (P < 0.0001), higher than all tested 100% cotton materials (all P < 0.05) as well as surgical masks (P < 0.05). Washing plus drying did not alter filtration performance significantly (P > 0.05). Conclusions: A filtration performance of common household fabrics were compared. Homemade mask designers and producers will have improved data to better balance effectiveness, availability, and comfort with the goal of decreasing community viral transmission.

scholarly journals Preliminary Evaluation of Filtration Efficiency and Differential Pressure ASTM F3502 Testing Methods of Non-Medical Masks Using a Face Filtration Mount

2021 ◽  
Vol 18 (8) ◽  
pp. 4124
Author(s):  
Charles Freeman ◽  
Reuben Burch ◽  
Lesley Strawderman ◽  
Catherine Black ◽  
David Saucier ◽  
...  
Keyword(s):  
Filtration Efficiency ◽  
Preliminary Evaluation ◽  
Testing Methods ◽  
Airflow Resistance ◽  
Minimum Standards ◽  
New Methods ◽  
Evaluation Procedures ◽  
Upper Limits ◽  
Control And Prevention ◽  
The Mean

Research surrounding the mandated use of non-medical fabric masks is inconsistent and often confusing when compared to the standard N95. A recently published standard from ASTM International and the Centers for Disease Control and Prevention attempts to normalize evaluation procedures. The purpose of this study is to conduct a preliminary evaluation of the new methods for testing filtration efficiency of masks outlined by ASTM International F3502, where results can be directly compared to standards outlined for non-medical fabric masks. Eleven consumer non-medical fabric masks were tested for filtration efficiency and airflow resistance using a face filtration mount in accordance with the newly released ASTM International standard for facial barriers. The mean FE% (SD) ranged from 0.46% (0.44) to 11.80% (2.76) with the 3-layer athletic mesh having the highest performance and the highest deviations. All the masks tested following the procedure failed to meet to minimum FE of 20%; however all masks performed below the minimum upper limits for airflow resistance. Using a non-medical fabric masks as the sole mitigation strategy may not be as effective, as previously reported. With efforts to standardize and regulate the non-medical fabric mask market, this study demonstrates a variety of currently available consumer mask products do not meet the minimum standards nor are these remotely close to the standards of surgical or N95 masks.

scholarly journals Development of Needle-Punched Nonwoven Fabrics from Reclaimed Fibers for Air Filtration Applications

2014 ◽  
Vol 9 (1) ◽  
pp. 155892501400900 ◽  
Author(s):  
S. Sakthivel ◽  
Anban J.J. Ezhil ◽  
T. Ramachandran
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Air Permeability ◽  
Filtration Efficiency ◽  
Raw Material ◽  
Fine Tuning ◽  
Physical Parameters ◽  
Air Filtration ◽  
Nonwoven Fabrics

This paper reports an investigative study on the fabrication and measurement of the air permeability, mechanical properties, pore size distribution, and filtration efficiency of different nonwoven fabrics produced from reclaimed fibers by analytically changing the machine variables to manipulate the physical parameters of the nonwoven fabrics. Reclaimed fiber of cotton (60%) and polyester (40%) blend was used, so that the prospect of value addition to an inexpensive source of raw material could be explored. The changes in air permeability were interpreted in terms of fabric density profile and pore size distribution. The filtration parameters of filtration efficiency, dust holding capacity, and pressure drop were also calculated. Additionally, the effects of calendering on pore size and filtration properties were evaluated to discover the opportunity of fine-tuning and the performance of the filters. The outcome in this study reflected an overall development in all filtration characteristics due to the calendering operation.

Preparation and filtration performance of the circular weft-knitted seamless weft-insertion fabric materials

2019 ◽  
pp. 152808371985532 ◽  
Author(s):  
Fei Tian ◽  
Gaoming Jiang ◽  
Zhe Gao
Keyword(s):  
Pore Size ◽  
Production Efficiency ◽  
Filtration Efficiency ◽  
High Porosity ◽  
Filtration Performance ◽  
Air Particulate ◽  
Forming Technology ◽  
New Type ◽  
High Production ◽  
Fabric Materials

Air particulate matter pollution has become a severe environment concern calling for filtration materials with great filtration performance. As the development of seamless forming technology, knitted filtration materials gradually show great potential. This study aimed to develop a novel kind of knitted seamless structure for filtration materials of filter bags with high production efficiency and excellent filtration performance. A new type of the circular weft-knitted seamless weft-insertion fabric (CKSW) filtration materials were developed on the modified circular knitting machine. This CKSW filtration materials consisting of the ground yarns, connection yarns and weft-insertion yarns, polyester full drawn yarns, and polyester draw texturing yarns with different yarn configurations were employed to realize series of CKSW samples. The polytetrafluoroethylene filaments with tourmaline particles were used to verify whether the static electric material produced an adsorption filtration effect on the CKSW filtration materials or not. After pretreatment, the filtration performance of the CKSW filtration materials was evaluated by analyzing its pore size, porosity, and filtration efficiency. Ultimately, the CKSW filtration materials with ground yarns and weft insertion yarns of draw texturing yarn and the connection yarns of full drawn yarn exhibited the most excellent filtration performance. The CKSW filtration materials show a high porosity of 87.14%, the pore size of 67.55 µm, and good filtration efficiency of 91.57% with the particles size of ≥ 5.0 µm. The successful fabrication of such knitted filtration materials may provide ideas for the development of filtration materials with new architecture mainly used as filter bags for baghouse.

scholarly journals COVID-19: smoke testing of surgical mask and respirators

2020 ◽  
Vol 70 (8) ◽  
pp. 556-563
Author(s):  
J D M Douglas ◽  
N McLean ◽  
C Horsley ◽  
G Higgins ◽  
C M Douglas ◽  
...  
Keyword(s):  
Health Care ◽  
Health Care Worker ◽  
Facial Trauma ◽  
Respiratory Protection ◽  
Complete Protection ◽  
Surgical Masks ◽  
Fit Testing ◽  
Working Shift ◽  
Smoke Chamber ◽  
Care Worker

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

Respiratory Protection by Respirators: The Predictive Value of User Seal Check for the Fit Determination in Healthcare Settings

2011 ◽  
Vol 32 (4) ◽  
pp. 402-403 ◽  
Author(s):  
Simon Ching Lam ◽  
Joseph Kok Long Lee ◽  
Linda Yin King Lee ◽  
Ka Fai Wong ◽  
Cathy Nga Yan Lee
Keyword(s):  
Electronic Device ◽  
World Health ◽  
Respiratory Pathogens ◽  
Respiratory Protection ◽  
Healthcare Settings ◽  
The World ◽  
Fit Testing ◽  
Control And Prevention ◽  
Health Organization ◽  
N95 Respirators

The N95 respirator is one type that is recommended by the World Health Organization and the Centers for Disease Control and Prevention (CDC) to prevent inhalation of droplets that may act to transmit respiratory pathogens. However, the reliability of this respirator to prevent transmission is dependent on how well it is fitted to the wearer. For ill-fitting respirators, the average penetration by ambient aerosol was found to be 33%, compared with 4% for well-fitting respirators. Such penetration or leakage may be caused by the gap between the respirator and the wearer's face. Therefore, formal fit testing should be carried out prior to the use of N95 respirators. Quantitative fit testing measures “the adequacy of respirator fit by numerically measuring the amount of leakage into the respirator” using an electronic device.

Bacterial Survival on Respirator Filters and Surgical Masks

1997 ◽  
Vol 2 (3) ◽  
pp. 32-43 ◽  
Author(s):  
Lisa M. Brosseau ◽  
Nicole Vars McCullough ◽  
Donald Vesley
Keyword(s):  
Bacillus Subtilis ◽  
Staphylococcus Epidermidis ◽  
Mycobacterium Abscessus ◽  
Bacterial Survival ◽  
Risk Of Infection ◽  
Surgical Masks ◽  
Before And After ◽  
Control And Prevention ◽  
Almost All ◽  
Subtilis Subsp

The Centers for Disease Control and Prevention recently developed recommendations for respirators worn to minimize exposures to Mycobacterium tuberculosis. These recommendations include criteria for filters and facial fit, but do not address how respirators are worn or disposed of. Handling may increase the risk of infection if loaded organisms remain viable. Respirator filters were challenged with aerosols containing three bacteria: Mycobacterium abscessus, Staphylococcus epidermidis, and Bacillus subtilis subsp. niger. Elution and surface contact sampling were used to recover organisms from filters after loading and following 5 days storage at 85% RH. Almost all filters showed culturable organisms immediately after loading. After storage, filters showed the least culturability for M. abscessus (20% of all filters) followed by S. epidermidis (61%), while B. subtilis remained highly culturable (98%). A slimilar trend was seen for the number of organisms recovered before and after storage (M abscessus demonstrated the least survival and B. subtilis the most).

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 Low-cost enhancement of facial mask filtration to prevent transmission of COVID-19

2020 ◽  
Vol 9 (5) ◽  
pp. 169-177
Author(s):  
Hari Bhimaraju ◽  
Nitish Nag ◽  
Ramesh Jain
Keyword(s):  
Activated Carbon ◽  
Low Income ◽  
Low Cost ◽  
Viral Transmission ◽  
Protective Equipment ◽  
Air Filters ◽  
Facial Mask ◽  
Surgical Masks ◽  
Aerosol Chamber ◽  
N95 Respirators

The use of face masks is recommended worldwide to reduce the spread of COVID-19. A plethora of facial coverings and respirators, both commercial and homemade, pervade the market, but the true filtration capabilities of many homemade measures against the virus are unclear and continue to be unexplored. In this work, we compare the following masks in keeping out particulate matter below 2.5 microns in decreasing order of their efficacy: N95 respirators, cloth masks with activated carbon air filters, cloth masks with HVAC air filters, surgical masks, heavily-starched cloth masks, lightly-starched cloth masks, and regular cloth masks. The experiments utilize an inhalation system and aerosol chamber to simulate a masked individual respiring aerosolized air. COVID-19 disproportionately affects people in low-income communities, who often lack the resources to acquire appropriate personal protective equipment and tend to lack the flexibility to shelter in place due to their public-facing occupations. This work tests low-cost enhancements to homemade masks to assist these communities in making better masks to reduce viral transmission. Experimental results demonstrate that the filtration efficacy of cloth masks with either a light or heavy starch can approach the performance of much costlier masks. This discovery supports the idea of low-cost enhancements to reduce transmission and protect individuals from contracting COVID-19.

scholarly journals Temporal Dynamics and Evolution of SARS-CoV-2 Demonstrate the Necessity of Ongoing Viral Genome Sequencing in Ontario, Canada

mSphere ◽  
2021 ◽  
Vol 6 (3) ◽  
Author(s):  
Calvin P. Sjaarda ◽  
Jennifer L. Guthrie ◽  
Samira Mubareka ◽  
Jared T. Simpson ◽  
Bettina Hamelin ◽  
...  
Keyword(s):  
Genetic Variants ◽  
Viral Genome ◽  
Temporal Dynamics ◽  
Viral Transmission ◽  
Mutation Rates ◽  
Protein Mutation ◽  
Rate Of Spread ◽  
Viral Mutation ◽  
Genome Wide ◽  
Control And Prevention

ABSTRACT Genome-wide variation in SARS-CoV-2 reveals evolution and transmission dynamics which are critical considerations for disease control and prevention decisions. Here, we review estimates of the genome-wide viral mutation rates, summarize current COVID-19 case load in the province of Ontario, Canada (5 January 2021), and analyze published SARS-CoV-2 genomes from Ontario (collected prior to 24 November 2020) to test for more infectious genetic variants or lineages. The reported mutation rate (∼10−6 nucleotide [nt]−1 cycle−1) for SARS-CoV-2 is typical for coronaviruses. Analysis of published SARS-CoV-2 genomes revealed that the G614 spike protein mutation has dominated infections in Ontario and that SARS-CoV-2 lineages present in Ontario have not differed significantly in their rate of spread. These results suggest that the SARS-CoV-2 population circulating in Ontario has not changed significantly to date. However, ongoing genome monitoring is essential for identification of new variants and lineages that may contribute to increased viral transmission.

scholarly journals The PPE Pandemic: Sex-Related Discrepancies of N95 Mask Fit

2021 ◽  
pp. 57-63
Author(s):  
Laura Christopher ◽  
Theresa Rohr-Kirchgraber ◽  
Saralyn Mark
Keyword(s):  
Direct Contact ◽  
Healthcare Professionals ◽  
Healthcare Personnel ◽  
Protective Equipment ◽  
Single Institution ◽  
Men And Women ◽  
International Council ◽  
The World ◽  
Fit Testing ◽  
Control And Prevention

During the COVID-19 pandemic, caused by the severe acute respiratory syndrome coronavirus 2, healthcare professionals across the world have been at high risk of transmission because of their direct contact with infected patients. In October 2020, the International Council of Nurses (ICN) confirmed that 1,500 nurses had died from COVID-19 in 44 countries and estimated that healthcare worker COVID-19 fatalities worldwide could be more than 20,000. To ensure protection of healthcare personnel, properly fitting personal protective equipment (PPE) must be worn. In a ‘one size fits all’ world, the differences between the fit of PPE for men and women can have devastating consequences. An N95 respirator mask is a component of PPE outlined by the Centers for Disease Control and Prevention (CDC) for protection against COVID-19; however, N95 masks do not offer protection if they do not fit properly. Fit testing is performed to ensure an adequate seal of the mask on the wearer. A single-institution retrospective review was performed on fit testing results for male versus female wearers in an attempt to elucidate a difference in failure rates. Females failed at a significantly higher rate than their male counterparts (6.67% female, 2.72% male; p=0.001), and the reason reported was often due to being ‘small-boned’ (p<0.0001). Sex-related differences in proper PPE fit are not new; however, the COVID-19 pandemic has made the situation more acute, and sex-specific N95 mask designs must be developed quickly, as the pandemic shows little signs of abating.

Sign in / Sign up

Export Citation Format

Share Document