Capture of 0.1-μm aerosol particles containing viable H1N1 influenza virus by N95 filtering facepiece respirators

Harnish, Delbert A.; Heimbuch, Brian K.; Balzli, Charles L.; Choe, Melanie; Lumley, April E.; Shaffer, Ronald E.; Wander, Joseph D.

doi:10.1080/15459624.2015.1116698

Cited by 9 publications

(13 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[39] Another study generated an aerosol CMD of ∼0.1 µm using viable H1N1 influenza to challenge N95 FFRs. [44] Thus, if there was interest, more challenging VFE methods could be developed by a standards development organization, although a modified VFE with an aerosol challenge in the MPPS range would still be considered unnecessary for determining FFR efficacy as noted previously. [44] The VFE method used in this study is adapted from the ASTM F2101 standard and is not being recognized by standard organizations.…”

Section: Discussionmentioning

confidence: 99%

“…[44] Thus, if there was interest, more challenging VFE methods could be developed by a standards development organization, although a modified VFE with an aerosol challenge in the MPPS range would still be considered unnecessary for determining FFR efficacy as noted previously. [44] The VFE method used in this study is adapted from the ASTM F2101 standard and is not being recognized by standard organizations. VFE method used in this study should not be considered useful for characterizing filter material efficiency.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

A comparison of facemask and respirator filtration test methods

Rengasamy

Shaffer

Williams

et al. 2016

Journal of Occupational and Environmental Hygiene

175

209

View full text Add to dashboard Cite

NIOSH published a Federal Register Notice to explore the possibility of incorporating FDA required filtration tests for surgical masks (SMs) in the 42 CFR Part 84 respirator certification process. There have been no published studies comparing the filtration efficiency test methods used for NIOSH certification of N95 filtering facepiece respirators (N95 FFRs) with those used by the FDA for clearance of SMs. To address this issue, filtration efficiencies of "N95 FFRs" including six N95 FFR models and three surgical N95 FFR models, and three SM models were measured using the NIOSH NaCl aerosol test method, and FDA required particulate filtration efficiency (PFE) and bacterial filtration efficiency (BFE) methods, and viral filtration efficiency (VFE) method. Five samples of each model were tested using each method. Both PFE and BFE tests were done using unneutralized particles as per FDA guidance document. PFE was measured using 0.1 µm size polystyrene latex particles and BFE with ∼3.0 µm size particles containing Staphylococcus aureus bacteria. VFE was obtained using ∼3.0 µm size particles containing phiX 174 as the challenge virus and Escherichia coli as the host. Results showed that the efficiencies measured by the NIOSH NaCl method for "N95 FFRs" were from 98.15-99.68% compared to 99.74-99.99% for PFE, 99.62-99.9% for BFE, and 99.8-99.9% for VFE methods. Efficiencies by the NIOSH NaCl method were significantly (p = <0.05) lower than the other methods. SMs showed lower efficiencies (54.72-88.40%) than "N95 FFRs" measured by the NIOSH NaCl method, while PFE, BFE, and VFE methods produced no significant difference. The above results show that the NIOSH NaCl method is relatively conservative and is able to identify poorly performing filtration devices. The higher efficiencies obtained using PFE, BFE and VFE methods show that adding these supplemental particle penetration methods will not improve respirator certification.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

A comparison of facemask and respirator filtration test methods

Rengasamy

Shaffer

Williams

et al. 2016

Journal of Occupational and Environmental Hygiene

175

209

View full text Add to dashboard Cite

show abstract

“…This similarity in filtration efficiency for different size microbes may reflect, in large part, the fact that the challenge was in the form of aerosol particles with MPS of ~3.0 μm. The particle size used was that stipulated in the relevant Standard (ASTM F2101) (12,13) and reflects the concern over transmission of infectious agents through fine aerosols, as has been demonstrated for influenza virus (25)(26)(27) and smallpox (variola) virus (28). The potential role of fine aerosols in transmission of a variety of viruses, such as measles, influenza, rhinoviruses, severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV), hantavirus (Sin Nombre virus), rabies, pox and Ebola viruses has been reviewed (7,8).…”

Section: Discussionmentioning

confidence: 99%

Assessment of a respiratory face mask for capturing air pollutants and pathogens including human influenza and rhinoviruses

Zhou¹,

Lukula²,

Chiossone³

et al. 2018

J. Thorac. Dis.

145

130

View full text Add to dashboard Cite

The masks, with or without features intended for enhancing comfort, provide protection against both small- and large-size pathogens. Importantly, the mask appears to be highly efficient for filtration of pathogens, including influenza and rhinoviruses, as well as the fine particulates (PM) present in aerosols that represent a greater challenge for many types of dental and surgical masks. This renders this individual-use N95 respiratory mask an improvement over the former types of masks for protection against a variety of environmental contaminants including PM and pathogens such as influenza and rhinoviruses.

show abstract

“…The cloth facemasks, depending on the type of fabrics, is reported to have virus (bacteriophage MS2) filtering efficiency of 50‒70% ( Davies et al, 2013 ). The virus filtering efficiency of three ply SMS (Spun bonded–Melt blown–Spun bonded) type surgical masks and N95 respirators was reported to be 85‒95%( Balazy et al, 2006 ; Davies et al, 2013 ) and 95‒97% ( Balazy et al, 2006 , p. 95; Harnish et al, 2016 ; Rengasamy et al, 2017 ; Zhou et al, 2018 ), respectively. A cluster randomized trial study on the effectiveness of cloth masks ( Davies et al, 2013 ), medical masks ( Leung et al, 2020 ) and respirators ( Radonovich et al, 2016 ) in hospital settings was also reported.…”

Section: Introductionmentioning

confidence: 99%

A smartphone microscopic method for rapid screening of cloth facemask fabrics during pandemics

Neupane

Chaudhary

Sharma

2020

PeerJ

View full text Add to dashboard Cite

Background In pandemics, because of increased demand and subsequent shortage of commercial facemasks, people need to use cloth facemasks, although such masks are reported to provide reduced protection. These masks can be prepared in local levels from different fabric materials. In developing countries, cloth masks are preferable because of low cost and added advantages of reusability. The filtering performance of a cloth facemask depends on the facial fit and on the material properties of fabrics such as porosity, yarn spacing or packing, and pore size. In resource limited settings, an affordable and easy to implement method that can assess the surface properties of cloth facemask fabrics would be important. Methods In this work, we developed a smartphone microscopic method for rapid screening of fabric quality. We measured the field of view of the microscope and as a proof of concept, we implemented the method to examine surfaces of sixteen locally available cloth mask fabrics. Results Out of the 16 masks examined, we found very diverse yarn packing and pore morphology (pore size and shape) in the fabrics. The pore size ranged from ~80 to 720 μm; much larger than respiratory droplet and bio-aerosol. This observation partly explains why such cloth facemasks provide reduced protection to the user during pandemics. The performance of a cloth facemask partly depends on the material properties of fabric such as yarn packing, pore size, porosity. Therefore, the surface properties of fabrics obtained from the smartphone method can be used to get preliminary idea on the facemask quality. We believe that the method can be an affordable and rapid method for selection of better fabrics for cloth facemask during pandemics.

show abstract

Capture of 0.1-μm aerosol particles containing viable H1N1 influenza virus by N95 filtering facepiece respirators

Cited by 9 publications

References 3 publications

A comparison of facemask and respirator filtration test methods

A comparison of facemask and respirator filtration test methods

Assessment of a respiratory face mask for capturing air pollutants and pathogens including human influenza and rhinoviruses

A smartphone microscopic method for rapid screening of cloth facemask fabrics during pandemics

Contact Info

Product

Resources

About