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

Lin, Tzu-Hsien; Tang, Feng-Cheng; Chiang, Chia-Hsiu; Chang, Cheng-Ping; Lai, Chane-Yu

doi:10.4209/aaqr.2015.03.0196

Cited by 16 publications

(30 citation statements)

References 17 publications

(23 reference statements)

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“…A facemask, as a kind of simple and convenient respirator, is widely used in daily life. It has been demonstrated that wearing facemasks for a long time can reduce the probability of infection from influenza-like illnesses (MacIntyre et al, 2009;Natarajan et al, 2016;Lin et al, 2017). Especially, functional facemasks are recommended for frontline healthcare workers to prevent splashes and sprays of blood, body fluids and the spread of infection from the wearer (Siegel et al, 2007;Agarwal et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

Preparation and Characteristic of Antibacterial Facemasks with Chinese Herbal Microcapsules

Wang

Kang

You

et al. 2017

Aerosol Air Qual. Res.

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Along with the current increases in human activities, air pollution, especially that generated from bioaerosols, has begun to receive more extensive attention. Among the bioaerosols, bacteria and fungi can result in organisms that are pathogenic to animals and humans. Therefore, a biological protective respirator with an antibacterial function would be a significant method by which to prevent epidemic spread of respiratory infectious diseases and protect human health. In this study, a type of facemask with an antibacterial function was prepared. The structure of the respirator included a respirator body and an inner filter layer that was assembled with herbal microcapsules. A kind of Chinese herb microcapsule developed through a cross-linking reaction method was successfully prepared to serve as an important component of the respirator. Scutellaria baicalensis (SB), a typical Chinese medicine, was employed to prepare the Chinese herb microcapsule. Three kinds of filter cloth (cotton, polyester fiber, and non-woven fabric, respectively) were employed to assemble with Chinese herb microcapsule. Meanwhile, the antibacterial performance and adhesion of the Chinese herb microcapsule for E. coli and S. aureus were investigated. The measurement results revealed that (i) the antibacterial efficiency of the Chinese herb microcapsule and the respirator filter was above approximately 99.999 and 96.000%, respectively; (ii) the adhesion of the herb microcapsules was still excellent after the filter was washed 100 times; (iii) the as-prepared antibacterial filter modified by an O 2 plasma-surface (PSM-O 2 ) treatment exhibited excellent antibacterial performance. Finally, a chamber simulation utilizing an Anderson first order sampler was designed to simulate the effect of wearing the antibacterial filter in a real environment. Overall, the respirator exhibited excellent biological protection properties compared with general masks, which will satisfy a vast number of application prospects.

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Section: Introductionmentioning

confidence: 99%

Preparation and Characteristic of Antibacterial Facemasks with Chinese Herbal Microcapsules

Wang

Kang

You

et al. 2017

Aerosol Air Qual. Res.

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“…The main test variable in this study is the survival of bacteria that were loaded on N95 FFRs that were decontaminated by various methods under worst‐case temperature and humidity, which prevail when an FFR is placed in a zipper bag in a healthcare worker's pocket with the goal of preventing cross‐contamination, and touching of the respirator . In the experiment, B. subtilis spores were the tested microbial strain; a six‐jet Collison nebulizer (BGI, Waltham, MA) sprayed the spores into a test system, shown in Figure , where they were loaded on N95 FFRs by suction to simulate the respiratory flow of workers during intensive activity . The experimental FFR was an N95 FFR (8210, 3M, St. Paul, MN), certified by NIOSH.…”

Section: Methodsmentioning

confidence: 99%

“… Ethanol: Ethanol with various concentrations and volumes was added to the center of the surface of the N95 FFR using a pipette, the FFR was then dried in a petri dish that was placed in a biosafety cabinet (BSC) for 10 minutes. Bleach: A 0.4 mL volume of bleach with various concentrations (5.4% (w/w) as Cl 2 : original; 2.7%: one part bleach to one part of deionized water; 0.54%: one part bleach to nine parts of deionized water) was added to the center of the surface of the N95 FFR using a pipette, the FFR was then dried in a petri dish in a BSC for 10 minutes. UV: An N95 FFR was placed 10 cm below a 6 W handheld UV lamp (model UVGL‐58, VUP LLC, Upland, CA) that emitted a wavelength of 254 nm (UVC, 18.9 mW/cm 2 ) or 365 nm (UVA, 31.2 mW/cm 2 ). Both sides of each N95 FFR were exposed for different times ‐ 1, 2, 5, 10 and 20 minutes ‐ in a BSC.…”

Section: Methodsmentioning

confidence: 99%

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Relative survival of Bacillus subtilis spores loaded on filtering facepiece respirators after five decontamination methods

et al. 2018

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This study determines the relative survival (RS) of Bacillus subtilis spores loaded on an N95 filtering facepiece respirator (FFR) after decontamination by five methods under worst-case conditions. Relative survival was obtained by testing after decontamination and after storing the FFRs at 37°C and 95% relative humidity for 24 hours. The decontamination methods involved ethanol, bleach, ultraviolet irradiation (UVA 365 nm, UVC 254 nm), an autoclave, and a traditional electric rice cooker (TERC) that was made in Taiwan. Without decontamination, 59 ± 8% of the loaded spores survived for 24 hours. When 70% ethanol was added to the N95 FFR at a packing density of 0.23, the RS was 73 ± 5% initially and decayed to 22 ± 8% in 24 hours. Relative survival remained above 20% after 20 minutes of UVA irradiation. The other four decontamination measures achieved 99%-100% biocidal efficacy, as measured immediately after the methods were applied to the test FFRs. Relative survival is a useful parameter for measuring sterilization or degree of disinfection. Bleach, UVC, an autoclave, and a TERC provide better biocidal efficacy than ethanol and UVA. Not only a higher filter quality but also a lower value of RS produced the most decontaminated FFR.

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“…For future respirator design, facial fit is a critically important parameter to consider for desired protection efficiency. Another problem lies with common materials of masks, such as active carbon and polypropylene melt-brown fabric, which might serve as hotbeds for bacterial growth and virus breeding on the mask, eventually causing secondary pollutants to people and the environment (Lin et al, 2015). In an effort to minimize the problem, some studies focus on developing new materials for respiratory masks, e.g., adding antibacterial agents such as nano-silver to the material of masks (Borkow et al, 2010;Natarajan et al, 2016) or using carbon nanotubes as filtration material (Guan and Yao, 2010;Xu and Yao, 2011;Zou and Yao, 2015).…”

Section: Bioaerosol Concentration Monitoring In a Classroom Before Dmentioning

confidence: 99%

Fluorescent Bioaerosol Particles Resulting from Human Occupancy with and Without Respirators

Yao

2017

Aerosol Air Qual. Res.

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Airborne transmission of pathogenic aerosols via human breath plays a major role in infectious disease outbreaks in indoor environments. Yet, their bioaerosol emission profiles are still not well quantified. Here, we first studied bioaerosol emission rates of human exhaled breath from 12 healthy subjects, and then evaluated the bioaerosol emissions when wearing two different respirators "Doctor masks" and N95 in a controlled environment (27 m 3 ) using a bioaerosol sensorultraviolet aerodynamic particle spectrometer (UV-APS). The human bioaerosol contribution was further confirmed through classroom observation. The results showed that there was a peak around 1.5 µm for the fluorescent particles emitted from humans' breath. For the controlled environment, the presence of 5 people without wearing masks increased bioaerosol concentration by 107% within 30 min at an average emission rate of 8. resulting from the occupancy. When wearing N95 masks or "Doctor masks", bioaerosol increases were observed to be 81% or 31% for the controlled environment, respectively, lower compared to those without masks. In-classroom observation also showed a fluorescent particle concentration increase of about 50%. In all experiments, we observed a decline in PM number concentration. Bioaerosol emission from exhaled breath was calculated to account for about 17% of the increase in the controlled environment. The results here suggest the need for re-evaluating microbial aerosol exposure risks for medical sites that demand high levels of hygiene even while wearing a respirator.

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

Cited by 16 publications

References 17 publications

Preparation and Characteristic of Antibacterial Facemasks with Chinese Herbal Microcapsules

Preparation and Characteristic of Antibacterial Facemasks with Chinese Herbal Microcapsules

Relative survival of Bacillus subtilis spores loaded on filtering facepiece respirators after five decontamination methods

Fluorescent Bioaerosol Particles Resulting from Human Occupancy with and Without Respirators

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