Face masks and respirators in the fight against the COVID-19 pandemic: An overview of the standards and testing methods

Forouzandeh, Parnia; O’Dowd, Kris; Pillai, Suresh C.

doi:10.1016/j.ssci.2020.104995

Cited by 102 publications

(85 citation statements)

References 29 publications

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“…The experimental procedure used in this paper is not fully in accordance with any filtration/mask testing national/regional/international protocol as it was developed as an urgent reaction to the demand for a practical mask assessment (using the equipment readily available) and not for actual accreditation purpose. According to the EU standards [ 9 , 10 , 11 ] and literature [ 13 ] the particulate filtration efficiency can be measured with a wide variety of particles such as 0.1-µm polystyrene latex particles or sodium chloride (NaCl) aerosols, where the PFE is determined either by counting the number of particles with an optical counter or measuring the concentration of the material with a flame photometer, upstream and downstream of the mask. During the tests various conditions and requirements need to be fulfilled such as the concentration of the particles, the size distribution of the particles, humidity and the airflow rate through the mask.…”

Section: Methodsmentioning

confidence: 99%

“…The penetration of particles through a mask is measured according to European Standard EN 13274-7 [ 12 ]. Masks are evaluated for a range of characteristics; the most common being breathability (meaning that the wearer should be able to breathe comfortably while wearing the mask), particulate filtration, bacterial filtration, as well as fluid resistance and flame resistance [ 13 ]. The present study focusses on filtration efficiency.…”

Section: Introductionmentioning

confidence: 99%

“…The present study focusses on filtration efficiency. The PRE, also called the particulate filtration efficiency (PFE) is defined as the ratio of the particles detected upstream and downstream of the mask [ 13 ]. Such tests are performed using 0.1 µm polystyrene latex particles which have been suspended in water, and the aerosols were created by means of a particle generator.…”

Section: Introductionmentioning

confidence: 99%

“…For bacterial filtration, Staphylococcus aureus is typically used (size ranges from 3.0 ± 0.3 µm). For the evaluation of viral filtration performance, which is not a standard test protocol, different types of viruses are used [ 2 , 13 ].…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Size- and Time-Dependent Particle Removal Efficiency of Face Masks and Improvised Respiratory Protection Equipment Used during the COVID-19 Pandemic

Krajnc

Pirker

Centa

et al. 2021

Sensors

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Size- and time-dependent particle removal efficiency (PRE) of different protective respiratory masks were determined using a standard aerosol powder with the size of particles in the range of an uncoated SARS-CoV-2 virus and small respiratory droplets. Number concentration of particles was measured by a scanning mobility particle sizer. Respiratory protective half-masks, surgical masks, and cotton washable masks were tested. The results show high filtration efficiency of FFP2, FFP3, and certified surgical masks for all sizes of tested particles, while protection efficiency of washable masks depends on their constituent fabrics. Measurements showed decreasing PRE of all masks over time due to transmission of nanoparticles through the mask-face interface. On the other hand, the PRE of the fabric is governed by deposition of the aerosols, consequently increasing the PRE.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Size- and Time-Dependent Particle Removal Efficiency of Face Masks and Improvised Respiratory Protection Equipment Used during the COVID-19 Pandemic

Krajnc

Pirker

Centa

et al. 2021

Sensors

View full text Add to dashboard Cite

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“…The tensile strength of melt blown polymer materials is in the range of 0.3 to 3 N and depends on the production process parameters [ 24 ]. However, the standards for disposable face masks and respirators do not include mechanical performance requirements for the equipment itself nor for filter material layers [ 26 ]. This allows us to conclude that the mechanical strength of the filter layer is not important unless it is possible to handle and process it in order to integrate it into personal protection equipment.…”

Section: Resultsmentioning

confidence: 99%

Mechanical and Air Permeability Performance of Novel Biobased Materials from Fungal Hyphae and Cellulose Fibers

et al. 2020

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Novel biobased materials from fungal hyphae and cellulose fibers have been proposed to address the increasing demand for natural materials in personal protective equipment (PPE). Materials containing commercially available kraft fibers (KF), laboratory-made highly fibrillated hemp fibers (HF) and fungal fibers (FF) obtained from fruiting bodies of lignicolous basidiomycetes growing in nature were prepared using paper production techniques and evaluated for their mechanical and air permeability properties. SEM and microscopy revealed the network structure of materials. The tensile index of materials was in the range of 8–60 Nm/g and air permeability ranged from 32–23,990 mL/min, depending on the composition of materials. HF was the key component for strength; however, the addition of FF to compositions resulted in higher air permeability. Chemical composition analysis (Fourier-transform infrared spectroscopy) revealed the presence of natural polysaccharides, mainly cellulose and chitin, as well as the appropriate elemental distribution of components C, H and N. Biodegradation potential was proven by a 30-day-long composting in substrate, which resulted in an 8–62% drop in the C/N ratio. Conclusions were drawn about the appropriateness of fungal hyphae for use in papermaking-like technologies together with cellulose fibers. Developed materials can be considered as an alternative to synthetic melt and spun-blown materials for PPE.

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Development of Functional Filter Materials for Virus Protective Face Masks

Zabihi

Reissner

Friese

et al. 2023

Adv Materials Technologies

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Wearing face masks during pandemics is an important protective measure against the spreading of virus‐related infectious diseases. Nevertheless, the risk of indirect transmission of virus by handling masks is one of the earliest concerns. This problem can be minimized by supplementing the masks’ textile structure with virus protective coatings. Therefore, in this concept, suitable techniques for manufacturing virus protective filter media should be evaluated. In this study, nonwoven polyamide 6 (PA6) filter material is functionalized with negatively charged linear polyglycerol sulfate (LPGS) as a virus binding functional group. Two coating conditions are investigated in which the direct covalent coating with LPGS has emerged as the optimum coating method, showing no damage to the PA6 nanofiber structure. The uncoated PA6 and LPGS‐coated PA6 filter materials exhibited virus particle filtration efficiencies of 95% and 94% for airborne feline coronavirus, 98% and 86% for airborne equine herpesvirus 1(EHV‐1), respectively. However, the SARS‐CoV‐2 absorption assay in solution indicates that the LPGS coating reduces viral titres up to 71% when incubating with the LPGS‐coated PA6 filter media for one‐hour. Thus, such an effect is not seen for uncoated PA6 materials. These findings confirm the suitability of LPGS coating as a suitable platform for suppression the spreading of viruses in different pandemics.

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Face masks and respirators in the fight against the COVID-19 pandemic: An overview of the standards and testing methods

Abstract: Graphical abstract

Cited by 102 publications

References 29 publications

Size- and Time-Dependent Particle Removal Efficiency of Face Masks and Improvised Respiratory Protection Equipment Used during the COVID-19 Pandemic

Size- and Time-Dependent Particle Removal Efficiency of Face Masks and Improvised Respiratory Protection Equipment Used during the COVID-19 Pandemic

Mechanical and Air Permeability Performance of Novel Biobased Materials from Fungal Hyphae and Cellulose Fibers

Development of Functional Filter Materials for Virus Protective Face Masks

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