An Overview Of Filtration Efficiency Through The Masks (part2)

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2. What is the filtering material in the mask?

Commonly used masks are composed of three layers of materials, and the filtering performance is mainly determined by the filter material in the middle. At present, the main filter material is a melt-blown non-woven fabric made of polypropylene superfine fibers, which is light and thin, has good air permeability, and can filter particulate matter in the air. The thicker the filter layer is not the better, it needs to be measured by professional equipment to verify its filtering effect. Therefore, the mask must have a layer of qualified filter material to have good filtration efficiency. The common two-layer non-woven masks and cloth masks on the market, if there is no intermediate filter layer, there is no real filtration efficiency.

 surgical mask

3. The difference in the index of filtration efficiency of different masks in different regions

Different masks have different requirements for filtration efficiency in different regions. Here we compare the index difference of the filtration efficiency of disposable medical masks (see the table below)

Regions

Standard

Class

BFE %

PFE %

China

YY/T 0969-2013

Normal medical

≥95

Not required

YY 0469-2011

For surgery

≥95

≥30

North America

ASTM2100-19

Level 1

≥95

≥95

Level 2

≥98

≥98

Level 3

≥98

≥98

Europe

EN14683:2019

Type I

≥95

Not required

Type II

≥98

Type IIR

≥98

Although studies have pointed out that there is a certain correlation between the filtration efficiency of non-oily particulate matter and the filtration efficiency of bacteria, the type of mask is not used, and its protective effect will also be very different. Therefore, when choosing a mask,  We need to choose the right mask based on actual demands.

 

Conclusions

Evidence from previous studies suggests that even face masks with less than 95% FFE (eg, surgical masks) are effective in preventing acquisition of epidemic coronaviruses (ie, severe acute respiratory syndrome coronavirus 1, SARS-CoV-2) by clinicians and other health care workers except possibly during aerosol-generating procedures. For prevention of a related coronavirus, severe acute respiratory syndrome coronavirus 1, N95 respirators had no increased prevention benefit over surgical masks. However, the CDC and Infectious Diseases Society of America has recommended the use of N95 respirators especially during aerosol-generating procedures as long as the supplies are available. This evaluation provides quantitative results on which health care administrators, supply chain leaders, and hospital epidemiologists can make evidence-based decisions to protect clinicians and other health care workers during a pandemic or long-term mask shortage.

 

About Wellmien

Wellmien provides globally medical care and food processing facilities with products including face masks, gowns, coveralls, aprons, bouffant caps, shoe covers, sleeve covers, under pads, disposable gloves, wound-care products, first-aid products and surgical packs etc. Our products are best sold to worldwide markets and widely applied to different settings such as hospitals, care centers, wholesalers, government agencies or institutes, food industries and households, etc. If you have any needs, please do not hesitate to contact us!

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