Face Mask Filtration Efficiency In A Classroom Environment

Presenter: Constantinos Manoli1
Co-Author(s): -
Advisor(s): nan
1St. Cyril of Alexandria Catholic School, Tucson, Arizona

Panapto Presentation Video
Poster PDF
Poster Session 1

This study investigated the filtration efficiency of different face masks using six testing techniques. The masks were divided into three categories: high efficiency KN-95 and N-95; fabric home/factory-made; and disposable, non-surgical masks. In addition, double masking was also tested. Existing literature on mask efficiency revealed a number of testing methods, we tested the five most reliable. The first method utilized an air particle counter to detect the presence of aerosols after exhaling the mist from a nebulizer. The second method tested the ability of each mask to prevent the detection of a strong odor. A third method tested the ability to blow a candle through the mask at various distances. The fourth method investigated the time it takes for 20ml of water to filtrate through each mask. Finally, a fifth method examined the porous structure of each mask under the microscope. A handheld CO2 meter was used in order to determine whether the air exhaled during breathing is truly filtered through the mask or whether it escapes from the sides due to poor mask design (fitting). This sixth method was improvised during class and directly related to the strapping options of each mask (behind the ears or around the head). For the most part, the conclusions aligned with those of the literature. High efficiency masks, such as KN-95 and N-95, outperform all others. Fabric masks are slightly better than disposable, non-surgical masks, however, it depends on the quality/structure of the mask. Double masking performs as well as high efficiency masks.

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