Comparison of Three Commercially Available Fit-Test Methods

Janssen, Larry; Luinenburg, Michael D.; Mullins, Haskell E.; Nelson, Thomas

doi:10.1202/0002-8894(2002)063<0762:cotcaf>2.0.co;2

Cited by 4 publications

(6 citation statements)

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“…The machine’s air inlet tubing was attached to the probe after an individual wore the respirator ( Figure S4C ). The machine calculated fit factor by using the following equation: 45 For material filtration tests, N95 and KN95 respirators were cut into 2 cm squares and placed into a 2 cm diameter cylindrical chamber with a swivel barb outflow adapter and an inflow tubing from the ambient atmosphere (Fig. S4B).…”

Section: Methodsmentioning

confidence: 99%

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Assessment of N95 and K95 respirator decontamination: fiber integrity, filtration efficiency, and dipole charge density

Yim

Cheng

Patel

et al. 2020

Preprint

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Personal protective equipment (PPE) including N95 respirators are critical for persons exposed to SARS-CoV-2. KN95 respirators and N95 decontamination protocols have been described as solutions to a lack of such PPE. However, there are a few materials science studies that characterize the charge distribution and physical changes accompanying disinfection treatments particularly heating. Here, we report the filtration efficiency, dipole charge density, and fiber integrity of pristine N95 and KN95 respirators before and after various decontamination methods. We found that the filter layer of N95 is 8-fold thicker than that of KN95, which explains its 10% higher filtration efficiency (97.03 %) versus KN95 (87.76 %) under pristines condition. After 60 minutes of 70 °C treatment, the filtration efficiency and dipole charge density of N95 became 97.16% and 12.48 µC/m2, while those of KN95 were 83.64% and 1.48 µC/m2 ; moreover, fit factor of N95 was 55 and that of KN95 was 2.7. In conclusion, the KN95 respirator is an inferior alternative of N95 respirator. In both systems, a loss of electrostatic charge does not directly correlate to a decrease in performance.

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Section: Methodsmentioning

confidence: 99%

“…The machine's air inlet tubing was attached to the probe after an individual wore the respirator (Figure S4C). The machine calculated fit factor by using the following equation: 45 Fit factor = 9:;<=>? @A (9@; >>) BC<A=D@ ;@A9=;:<B; 9:;<=>?…”

Section: Fit Factor and Materials Filtration Testmentioning

confidence: 99%

Assessment of N95 and K95 respirator decontamination: fiber integrity, filtration efficiency, and dipole charge density

Yim

Cheng

Patel

et al. 2020

Preprint

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“…The amount of the evacuated air precisely corresponds to the leaked one. The whole procedure takes only 7-10 s [12]. The method is notable for a relatively low cost of the equipment; though, it cannot be applied for the filtering half-masks.…”

Section: Analysis Of Scholarly Research Sourcesmentioning

confidence: 99%

“…3. The coefficient of suction through the gap along the obturation line is calculated according to the formulas [12] η n = 1 -5. Table 2 shows the measured values of pressure difference for Lepestok-type respirator and various dummies.…”

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confidence: 99%

Evaluation оf the Protective Properties of Filtering Half-Masks by Measuring Pressure Difference

Golinko¹,

Cheberiachko²,

Yavorska³

2018

Nauka innov.

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Introduction. An important characteristic of respirator is the capability of its half-mask to protect the respiratory organs against the surrounding contaminated atmosphere due to a tight half-mask-face contact. Problem statement. Keeping a constant pressure difference under the mask is a low-cost and simple method of alternative diagnostics of half-mask protective properties involving special-purpose test aerosols. The method is based on the determination of the air amount entrained through the gaps while generating rarefaction within the under-mask area. However, there have been no recommendations on the use of the method for evaluating the insulating properties of lightweight filtering half-masks from under which it is impossible to evacuate air. Purpose is to represent a simplified method with measuring the rarefaction under a filtering half-mask making possible to determine its insulating properties and protection coefficient. Materials and Methods. Protection coefficient of respirator can be evaluated in terms of air amount passing through the filtering material and gaps with the preset coefficient of penetration and suction. The latter is calculated as coefficient of aspiration into the gap of the preset length. Air consumption is determined experimentally as pressure difference between the half-mask mounted tightly on a dummy and the tubes of preset diameter positioned along the obturation line. Results. A calibration line of the relation between the pressure difference and the air consumption through a gap for the filtering half-masks has been developed. Coefficients of insulation and protection of Lepestok-type respirators have been calculated. The protection coefficients have been established to proportionally depend on the ratio of air consumption through a filter and gaps between the face and the half-mask along the obturation line. Conclusions. It has been proved that the methods for determining the protective properties of filtering half-masks in terms of measuring pressure difference may be used as a low-cost alternative to expensive diagnostics of the quality of respiratory protective devices. Also, they can be employed for selecting and training workers to properly use the respirators under manufacturing conditions in accordance with EN 529:2006 requirements. K e y w o r d s: concentration of harmful substances, coefficient of penetration, air consumption, protective properties, and filtering half-mask.

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“…However, there is no standard method for simultaneously evaluating the relative efficiency of the filter media and fit when challenged with a bioaerosol. The objective of our study was to develop and evaluate a standard method for use in testing the relative efficiency of commercially available RPE for reducing exposure to a bioaerosol, taking into account previously published studies [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]. We selected a sampling method based on work by Green and Scarpino [9] and Scarpino et al [10] in a controlled bioaerosol chamber.…”

Section: Introductionmentioning

confidence: 99%

Method for Evaluating the Relative Efficiency of Selected N95 Respirators and Surgical Masks to Prevent the Inhalation of Airborne Vegetative Cells by Healthcare Personnel

Davidson

Green

Panlilio

et al. 2010

Indoor and Built Environment

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Aerosol droplet- and airborne-transmitted diseases are an important healthcare concern. The anthrax attacks of 2001, severe acute respiratory syndrome outbreaks in 2003 which resulted in transmission to numerous healthcare personnel (HCP) and concerns about smallpox as a bioterrorist agent have contributed to heightened concern about airborne infectious agents. Respirators and surgical masks can provide respiratory protection against such airborne diseases but their efficacy needs to be assessed. This study describes a method for quantitatively assessing the relative efficiency of respiratory protective equipment (RPE) when challenged with a bioaerosol. Five surgical masks, three N95 respirators and three surgical N95 respirators were evaluated. All are commercially available and used in US healthcare settings. Bacterial aerosols of vegetative Bacillus anthracis strain Sterne 34F2 (a surrogate for pathogenic B. anthracis) were generated with a six-jet Collison nebuliser. To mimic human respiratory breathing, an automated breathing simulator (ABS) calibrated to normal tidal volume and active breathing rate (500 mL/breath and 20 breath/min, respectively) was used. Respirators were placed on manikin head-forms designed for use in cardiopulmonary resuscitation training and used in our investigation as surrogates for HCP. The method showed that a Collison nebuliser could generate monodisperse bacterial aerosol to effectively test RPE total inward leakage. Also, the AGI-30 air samplers, combined with the ABS, provided an accurate method of quantifying RPE relative efficiency. For the 11 RPE this ranged from 34% to 69% with statistically significant differences between several RPE models. We conclude that neither RPE type nor brand name was an indicator of RPE relative efficiency.

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Comparison of Three Commercially Available Fit-Test Methods

Cited by 4 publications

References 0 publications

Assessment of N95 and K95 respirator decontamination: fiber integrity, filtration efficiency, and dipole charge density

Assessment of N95 and K95 respirator decontamination: fiber integrity, filtration efficiency, and dipole charge density

Evaluation оf the Protective Properties of Filtering Half-Masks by Measuring Pressure Difference

Method for Evaluating the Relative Efficiency of Selected N95 Respirators and Surgical Masks to Prevent the Inhalation of Airborne Vegetative Cells by Healthcare Personnel

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