Type of Mask

Filtering Capacity and Protection

Author, year

Professional N95 Respirators

-Removes 95% of the smallest droplets

-It fits around the nose and mouth with a strong seal, so air and viral particles will not get around the side of the respirator.

Asadi et al., 2020 [19]; Bartoszko et al., 2020 [20]; Gralton & McLaws, 2010 [21]; John Hopkins, 2020 [43];

MacIntryre & Chughtai, 2020 [44];

NIH, 2020 [5]

Procedural and Surgical Masks

-Seal around the nose and the mouth, meaning smaller droplets can still be inhaled.

-Surgical masks are useful for shielding the nose and mouth from larger droplets from coughs or sneezes and for preventing the transmission of droplets by infected individuals.

-Around 60% of the tiny inhaled particles can be filtered out by surgical face masks. They are mainly meant to avoid droplets, sprays and splatters.

Asadi et al., 2020 [19]; Bartoszko et al., 2020 [20]; Gralton & McLaws, 2010 [21]; John Hopkins, 2020 [43];

Fink, 2020 [45];

MacIntryre & Chughtai, 2020 [44];

NIH, 2020 [5]

Cloth masks with filter

-Some big droplets are removed by homemade cloth masks but provide little protection against aerosols.

-They do not have a seal around the nose and mouth, and face shields are unlikely to increase their effectiveness. Cloth masks worn by infected individuals can decrease the spread of droplets if surgical masks are not available.

-Filtration can be improved by 35% to almost 70% by applying a polypropylene filter to a two-layer cloth mask.

- Results highlight the importance of regular changing of disposable masks and washing of homemade masks.

Asadi et al., 2020 [19]; John Hopkins, 2020 [43];

Felter, 2020 [36];

Fink, 2020 [45];

Ghandhi, 2020 [29]; Rengasamy, Eimer & Shaffer, 2010 [28]

Cloth or Paper Mask

-Single-layer masks can only provide 1 percent filtration of particles. Around 35 percent of the small particles are filtered by a two-layer cotton mask. From 8 feet to 2,1⁄2 inches, cotton face masks will minimise droplet spray.

-A homemade cloth face mask 's efficacy depends largely on its construction. Thickly woven cotton fabrics, such as quilting cotton. Single-layer cloth masks, which could be less efficient than triple-layer masks, are less efficient than double-layer masks.

- While the efficacy of cloth and paper masks is not as clear and confounded by shedding of mask fibers, it is likely that they provide some reductions in emitted large expiratory particles (> 0.5 μm).

-Results highlight the importance of regular changing of disposable masks and washing of homemade masks.

Asadi et al., 2020 [19]; John Hopkins, 2020 [43];

Fink, 2020 [45];

Ghandhi, 2020 [29]; Rengasamy, Eimer & Shaffer, 2010 [28]

Cone style masks

-Cone-style face masks are less functional than cloth face masks. It is made of quilting cotton to accommodate droplets and spray.

-Bandanas are more effective the cone-style masks.

Fink, 2020 [45]

Bandana

-Bandana covering the mouth and nose is a good way to keep dust and other particles out of the respiratory system.

- Bandanas offer some protection against droplets and "spray" related to cough or sneeze.

-Without shielding the nose or mouth, droplets can spray more than 8 feet, and with the bandana it can decrease up to 4 feet.

Fink, 2020 [45]

T-shirt mask

-Not effective

-1/3 effective as surgical masks

-More than 1 layer of material can increase the effectivity

Fink, 2020 [45]