• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.9 no.1
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• pp.14-22
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• 1999

This study was conducted to evaluate workplace protection factors(WPF) for two half-facepiece respirators (HR-1, HR-2) in welding workplace and to provide data on the workplace performance of negative-pressure, half-facepiece respirators against airborne particulate contaminants. The outside iron oxide(Fe2O3) concentration of welding fume for the respirator HR-1 ranged from 0.177 to $12.508mg/m^3$ with a geometric mean of $1.118mg/m^3$ and the HR-2 respirator showed a iron oxide range of 0.500 to $3.494mg/m^3$ with a geometric mean of $1.082mg/m^3$. But the inside oxide concentration of welding fume for the respirator HR-1 ranged from 0.002 to $0.364mg/m^3$ with a geometric mean of $0.019mg/m^3$ and the HR-2 respirator showed a iron oxide range of 0.012 to $0.639mg/m^3$ with a geometric mean of $0.041mg/m^3$. The iron oxide inside concentrations were significantly less than $5mg/m^3$(TLV) for both of respirators. The WPF were ranged from 3 to 3744 with a geometric mean of 60 for HR-1 and range from 2 to 129 a geometric mean of 26 for HR-2. And, in this study, the 5th percentile of the workplace protection factors for half-facepiece aspirators (HR-1, HR-2) were 11.2 and 7.1, respectively. The correlation relationship between the Quantative Fit Factors(QNFT) and the WPF for half-mask negative pressure respirators were 0.099 and 0.460.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.30 no.2
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• pp.124-133
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• 2020

Objectives: Mask fit is a crucial factor in preventing respiratory infections among healthcare workers. The current coronavirus(COVID-19) pandemic calls for the replacement of imported N95 medical masks with domestic N95 versions. In this study, we aimed to determine whether these masks provide proper protection. Methods: Thirty-five participants from three healthcare institutions donned four types of masks and Quantitative Fit Tests(Portacount, USA) were performed. The order of fit test for the four types of masks was randomized, and a three-minute washout period was applied between test times(2 min 29 sec) to reduce potential error stemming from physical exhaustion. Results: There were no significant differences in the Fit Factor for the four types of masks, and there were no gender differences. However, the Fit Factor significantly differed across the three healthcare institutions (p=0.007). With eight of the 35 participants passing, the pass rate with the criteria of 100 or higher was 21%. Conclusions: The mask used in this study was a new domestic N95 medical mask, and the participants were unfamiliar with how to wear it. They reported difficulties with mask fitting. In light of a previous finding that mask fit improved with frequently used masks, wearer preferred masks, or when masks that are regularly worn are used during fit training, the fact that participants were unfamiliar with the mask used in this study is a limitation that should not be overlooked.

• Journal of the Korean Society of Safety
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• v.33 no.1
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• pp.47-53
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• 2018

This study compares the interrelation of fit factor(FF) and visual acuity test by the order of wearing preference between Particulate filtering face piece respirators(PFFR) and glasses for 54 participants. Glasses fitting factors is Optical Center Height(OH), Vertex Distance(VD) and Pantoscopic Angle(PA) or Visual acuity. We measured those factors and expressed by the ratio of standard point and change point. Quantitative fit factor was measured by Portacount Pro+ 8038 and compared the result of preference of wearing order between respirators and glasses. Also, we selected to 6 exercises among 8 exercises OSHA QNFT (Quantitative Fit testing) protocol to measure the fit factors. The pass/ fail criterion of FF was set at 100. Visual acuity test chart is developed by Chunsuk Han was used, Descriptive statistics was performed. Descriptive statistics(SAS ver 9.2), it is used geometric means, Wilcoxon analysis, peason correlation(P=0.05) Fit factor was increased when the respirator was worn before wearing the glasses(p=0.000) and decreased for visual acuity(p=0.000) The negative correlation was showed between OH and Overall fit factor(r=-0.409, p=0.002). Among 54 participants, 11 participants(20.3%) were worn respirator before wearing glasses and 1 participant(1.9%) was worn glasses before wearing respirator. The overall fit test showed the higher level was investigated for the group of participants wearing respirator before wearing glasses in 6 exercises. Also, overall fit factor were increased when participants wore glasses prior to respirator(16.6) to respirator prior to glasses(36.6). Visual acuity were increased when participants wore respirator prior to glasses(93.8) to glasses prior to respirator(106.0). Finally, comparison result of overall fit factor and visual acuity were glasses first choice from mask first choice. The results showed that higher overall fit factor was investigate when the participants wore the respirator prior to glassess at all. The results implied that it is important to maintain the overall fit factor and visual acuity according to the consideration of OH for glasses fitting when worker wore respirator and glasses at the same time.