In December 2019, a novel coronavirus was detected in China. Since its discovery, it has swiftly spread throughout the world. This novel coronavirus was then named as SARS-CoV-2, and the illness that it causes is termed as COVID-19. Older adults and those with underlying health conditions are most at risk for serious illness which include symptoms such as fever, difficulty breathing, pneumonia, and even respiratory failure.
Through small respiratory droplets, SARS-CoV-2 can be transmitted from person to person. These small respiratory droplets are made when an infected person exhales, talks, coughs, or sneezes. With that, you can contract the virus if you breathe in these droplets. Moreover, studies have shown that respiratory droplets containing the virus can land on objects or surfaces. Hence, there is a possibility that you could get infected with SARS-CoV-2 if you touch these surfaces and then touch your eyes and nose after. However, it must be noted that this is not the primary way that the virus is transmitted from person to person. Because SARS-CoV-2 is easily transmitted, there have been rising cases of COVID-19. With that, scientists and health experts have come together to come up with a prevention strategy
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Face mask is a scientifically proven effective material you can utilize in order to protect yourself from having COVID-19. Studies have shown that properly wearing face masks, which means covering your nose and mouth, can have approximately 95% protection against SARS-CoV-2.
So when you hear about face masks, there are typically three types. These include homemade cloth face masks, N95 respirators, and surgical masks. One of the most common and most effective types of face masks out there is the 3 ply surgical face mask. But the question is: what really makes this face mask special? So if you are curious about the answer, then keep on reading!
What is a 3 Ply Face Mask?
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A 3 ply face mask is disposable, loose-fitting face mask that covers your nose, mouth, and chin. If worn properly, surgical masks can aid in blocking out most, if not all, large-particle droplets, splashes, sprays, or splatter that may contain viruses and bacteria, keeping them from entering the wearer's nose and mouth and conversely are also effective barriers for retaining large droplets released from the wearer's the mouth and nose. With that, the 3-ply surgical mask is usually used in the COVID-19 pandemic. As the name implies, the 3-ply surgical mask is manufactured through the combination of 3 various layers of nonwoven fabric with each layer having a vital function. Here are the parts of a 3 ply face mask:
- The outermost layer is the waterproof layer which aids in keeping out fluids such as mucosalivary and respiratory droplets.
- The middle layer is the filter. This layer blocks particles or pathogens above a specific size from penetrating in both directions.
- The innermost layer is made of absorbent materials to confine mucosalivary droplets from the user. This also improves comfort through absorbing the moisture from exhaled air.
When combined together, these 3 layers effectively protect both the user and the surrounding people by reducing the penetration of particles and pathogens in either direction.
In addition to that, 3 ply masks are made of nonwoven fabric. As its name suggests, nonwoven fabric is not composed of intertwining strands, rather it is produced through bonding a mass of fibres together by heat, chemical, or mechanical procedure. Moreover, nonwoven fabric is cheap and fast to manufacture. With that, nonwoven fabric is the ideal material for surgical masks. The two most common methods of making nonwoven fabric for surgical masks are spunbond and melt-blown. Both of these technologies can process a great variety of thermoplastic such as polypropylene, polyester, polyethylene, polyamide, and polyurethane. Polypropylene is the most common material utilized for a 3-ply surgical mask.
What makes 3 Ply Mask Special?
There are a number of different types of face masks and respirators offering different levels of protection to users. These masks can either be reusable or disposable. Industrial-use half or full facepiece respirators with cartridge filters attached and homemade or commercial cloth masks are considered as the reusable ones, while surgical masks, N95 respirators, and KN95 respirators are considered as the disposable ones. It must be noted that all these face masks serve the general purpose of providing some form of protection against contaminants in the air.
The level of protection against pollutants and pathogens is greatly dependent on the filtering capacity which highly depends on the materials used and the engineering design. SARS-CoV-2 has a size of approximately 60 to 140 nm. This size is smaller than bacteria, dust, and pollen. Hence, masks made of materials with larger pore sizes, such as those made from cotton and synthetic fabric, will not be able to effectively filter these viruses or tiny virus-laden droplets, as compared with those made of materials with smaller pore sizes. Moreover, masks made of or coated with water-resistant materials are significantly more effective in repelling large virus-laden respiratory droplets and fluid spills.
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In this case, a 3-ply face mask is the most effective and standard product to prevent the entry of SARS-CoV-2. The 3-ply face mask has passed the requirements set by international and national standards organizations such as the American Society for Testing and Materials (ASTM). The ASTM is responsible for setting the masks as certified protective devices. In order to be classed as a medical mask, manufacturers have met required standards from raw materials to finished product. The performance requirements classify the product as Level 1, 2, or 3. There are basically five criteria to reach standard in order to qualify as an ASTM Medical Mask. It must be noted that the higher the performance rating of the mask, the greater the protection. Here are the following criteria:
- Fluid Resistance –This means that the mask is resistant to penetration by synthetic blood under pressure (mmHg). The higher resistance, the higher protection.
- PFE Particle Filtration Efficiency – This is the percentage of particles filtered out at a pore size of about 0.1 – 1.0 microns (µ).
- BFE Bacteria Filtration Efficiency – This is the percentage of particles filtered out at a pore size of 1.0 – 5.0 microns (µ).
- Delta P Differential Pressure – This is the pressure drop across mask, or resistance to air flow in mmH2O/cm2 . The greater resistance, the better protection (however there is also less breathability).
- Flame Spread – this measures the flame spread of the mask material.
A 3-ply face mask has passed this criteria set by the ASTM. In addition to these criteria, 3-ply face masks must also be tested to an ISO certification that makes sures that no materials have been utilized in making the mask that are harmful to the wearer as it comes in contact with their skin. Furthermore, a 3-ply medical mask can be level 1, 2, or 3. A Level 1 Disposable Medical Mask is ideal for scenarios where low amounts of fluid, spray and aerosol are produced. Level 2 are for procedures where moderate amounts are produced and Level 3 is for surgery. It must be noted that ASTM Level 1 requirements include Fluid Resistance of greater than 80mmHg, PFE of greater than 95%, and BFE of greater than 95%.
Unlike disposable 3 ply protective face masks, there are also other disposable medical face masks that are common in the market right now and are usually manufactured in China. With that, it must be noted that the Chinese National Standards for disposable masks are not required to meet the standards of ASTM Level 1 Mask. For example, for disposable protective face masks made in China, fluid resistance, PFE, or BFE may not be required. With that, it may not bring the level of protection against SARS-CoV-2 compared to those 3-ply face masks that are manufactured in Canada and tested under the ASTM.
Face mask, when worn properly, is an effective protection against SARS-CoV-2. The 3-ply face mask that is certified by the ASTM is the best one you can get in the market. Now that we have outlined the details on why the 3-ply face mask is special, we hope that you always wear them, especially when going out, so that we can protect ourselves and others from COVID-19.
- ASTM. F2100-19e1, Standard Specification for Performance of Materials Used in Medical Face Masks. West Conshohocken, PA, USA: ASTM International; 2019.
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