Factors Affecting Filter Penetration and Quality Factor of Particulate Respirators

Huang, Sheng-Hsiu; Chen, Chun-Wan; Kuo, Yu-Mei; Lai, Chane-Yu; McKay, Roy T.; Chen, Chih-Chieh

doi:10.4209/aaqr.2012.07.0179

Cited by 127 publications

(110 citation statements)

References 29 publications

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“…5(a) show that the penetration efficiency for charcoal cartridge against NaCl aerosols was increased with the increase of air intake, but decreased with the increase of particle size (less significant). Huang et al (2013) also found that aerosol penetration through filter media increased with increasing face velocity. According to the NIOSH (1996) requirements for P100 filters or the Department of Energy (2015) requirements for HEPA filters, the filtration efficiency against the most penetrating particle size (MPPS) (0.3 µm) should be at least 99.97%.…”

Section: Penetration Efficiency Of Aerosols In Charcoal Cartridgesmentioning

confidence: 84%

Performance Evaluation of Full Facepiece Respirators with Cartridges

Lee

Chen

Hwang

et al. 2017

Aerosol Air Qual. Res.

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Full facepiece respirators (FFRs) with charcoal cartridges are very common wearable devices for industrial or military purposes preventing respiratory tract, face, eyes, and mouth from hazards exposure. However, related research for performance evaluation was rare. We aimed to use a self-developed testing system investigating (1) filtration efficiency (FE) of aerosols in charcoal cartridges; (2) breakthrough time of cyclohexane in charcoal cartridges; (3) fit factors (FFs) and (4) protection factors (PFs) of FRRs. The results showed that FE of charcoal cartridges against 0.3 µm of sodium chloride (NaCl) and dioctyl phthalate (DOP) particles under 85 L min -1 were 99.93% and 99.89%, respectively, which did not meet the standard 99.97% regulated for filters such as P100 and HEPA. As for 42.5 L min -1 condition (dual canisters), the FE against NaCl (99.97%) did meet the requirement set for HEPA (99.97%); however, that against DOP (99.95%) failed to meet the standard. In addition, the breakthrough time of 3000ppm cyclohexane was 31 min under 32 L min -1 , which was longer than the 30 min standard described in CNS6636 Z2023 and JIS8152. As to the results of fit test among 21 subjects, only 1 failed to meet the requirement (fit factor = 500) and the average of fit factors was 8342 ± 5892. The mean value of protection factors was 112.3 ± 54.6 while 3 users had lower PFs than the assigned protection factor (APF = 50) regulated by Occupational Safety and Health Administration (OSHA). APFs obtained for particles less than 100 nm were smaller than the APF standard regulated by OSHA, indicating APF standards may be overestimated for such particle size. Therefore, users should be aware of potential risks caused by such substances in nano-sized scale (e.g., nanoparticles or viruses) when wearing FFRs.

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Section: Penetration Efficiency Of Aerosols In Charcoal Cartridgesmentioning

confidence: 84%

Performance Evaluation of Full Facepiece Respirators with Cartridges

Lee

Chen

Hwang

et al. 2017

Aerosol Air Qual. Res.

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“…Higher porosity and larger fiber diameter can lead to lower pressure drop, and also negatively impact on the collection efficiency. Therefore, determination of the optimum points among the effecting parameters is so important (Huang et al, 2013). Wang et al (2008) showed that filter efficiency had a negative exponential relationship with the fiber diameter and a positive exponential relationship with solid volume fraction (equal to one minus the porosity), and filter pressure drop had a negative exponential relationship with porosity and fiber diameter (Wang et al, 2008).…”

Section: Determination Of Optimal Conditionsmentioning

confidence: 99%

“…Normally, the lower packing density, higher porosity, thinner filters, and larger fiber diameter can lead to lower pressure drop, whereas all of these properties lead to lower collection efficiency. Therefore, finding the optimum balance between these two factors is very critical (Huang et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

Optimization of electrospinning parameters for polyacrylonitrile-MgO nanofibers applied in air filtration

Dehghan

Golbabaei

Maddah

et al. 2016

Journal of the Air & Waste Management Association

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The present study aimed to optimize the electrospinning parameters for polyacrylonitrile (PAN) nanofibers containing MgO nanoparticle to obtain the appropriate fiber diameter and mat porosity to be applied in air filtration. Optimization of applied voltage, solution concentration, and spinning distance was performed using response surface methodology. In total, 15 trials were done according to the prepared study design. Fiber diameter and porosity were measured using scanning electron microscopic (SEM) image analysis. For air filtration testing, the nanofiber mat was produced based on the suggested optimum conditions for electrospinning. According to the results, the lower solution concentration favored the thinner fiber. The larger diameter gave a higher porosity. At a given spinning distance, there was a negative correlation between fiber diameter and applied voltage. Moreover, there were curvilinear relationships between porosity and both spinning distance and applied voltage at any concentration. It was also concluded that the developed filter medium could be comparable to the high-efficiency particulate air (HEPA) filter in terms of collection efficiency and pressure drop. The empirical models presented in this study can provide an orientation to the subsequent experiments to form uniform and continuous nanofibers for future application in air purification.Implications: High-efficiency filtration is becoming more important, due to decreasing trends air quality. Effective filter media are increasingly needed in industries applying clean-air technologies, and the necessity for developing the high-performance air filters has been more and more felt. Nanofibrous filter media that are mostly fabricated via electrospinning technique have attracted considerable attention in the last decade. The present study aimed to develop the electrospun PAN-containing MgO nanoparticle (using the special functionalities such as absorption and adsorption characteristics, antibacterial functionality, and as a pore-forming agent) filter medium through experimental investigations for application in high-performance air filters.PAPER HISTORY

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“…The filter quality factor (q f ) combines P and ∆p, and is an index of filter media performance (Huang et al, 2013). The term q f is defined as follows.…”

Section: Effects Of Loaded Bacteria On Filter Performancementioning

confidence: 99%

Recovery of Bacteria in Filtering Facepiece Respirators and Effects of Artificial Saliva/Perspiration on Bacterial Survival and Performance of Respirators

Lin

Tang

Chiang

et al. 2017

Aerosol Air Qual. Res.

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This study seeks the optimal method for recovering loaded bacteria from filtering facepiece respirators (FFRs) and investigates the effects of artificial saliva (AS), artificial perspiration (AP) and storage conditions on the survival of bioaerosols and the filter performance of FFRs. Bioaerosols were generated using a Collison nebulizer in a test system and loaded on either N95 or surgical masks. Elution using centrifuge at 3500 rpm for ten min followed by vortexing for one min yielded a high relative survival (RS) rate of airborne Bacillus subtilis (BS) spores. When AS was added to the N95 FFR, the RS of BS declined during the first eight hours of storage and then increased to reach its highest value after 24 hr of storage. The worst case with the highest RS was at 37°C and 95% RH (p < 0.001). When AP was added to the N95 FFR and stored under the worst conditions, RS increased by over 100% during eight hours of storage. When AS was added to a surgical mask, the RS also increased by over 100% in eight hours of storage, but when AP was added to the surgical mask, RS immediately declined. When Escherichia coli (EC) were tested, their RS was lower than those of the BS samples. (Following loading with bacteria, the particle penetration and filter quality factor (q f ) increased (p < 0.001) but the slope of the linear regression between the pressure drop (∆p) and the flow rate through the filter was not statistically significantly changed (p = 0.233). In conclusion, AS and AP increased the survival of BS; AP was especially effective in N95 masks and AS was especially effective in surgical masks.

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Factors Affecting Filter Penetration and Quality Factor of Particulate Respirators

Cited by 127 publications

References 29 publications

Performance Evaluation of Full Facepiece Respirators with Cartridges

Performance Evaluation of Full Facepiece Respirators with Cartridges

Optimization of electrospinning parameters for polyacrylonitrile-MgO nanofibers applied in air filtration

Recovery of Bacteria in Filtering Facepiece Respirators and Effects of Artificial Saliva/Perspiration on Bacterial Survival and Performance of Respirators

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