Ever since the posting of the last post about the KF-AD mask, we had quite few people who were curious about it. So, in today’s post I will be going into more details about the mask.
The KF-AD (anti-droplet) mask is quite literally like what the name would suggest. An anti-droplet mask that is specialized in blocking droplets like saliva, which are one of the most prominent methods of transmission of COVID-19. The mask itself is also has high ventilation, making it easy to breathe through. Last summer, in Korea, there was a high demand for the breathable and light surgical masks. But it wasn’t easy for most people to get access to them due to most of the supplies being secured by the government for medical personnel and unlike the usual health masks the medical grade surgical mask’s rate of productions could not keep up with the demand. So, the Ministry of Food and Drug Safety to supply a similar mask to people designated the anti-splash mask as a “therapeutical device”.
With the approval of the Ministry, the KF-AD mask was manufactured to be distributed, with clear indications on the packaging that it was a “therapeutical device”. The AD (anti-droplet) certification on the mask can only be obtained if the mask passes the liquid resistance test, which tests if droplets with a minimum diameter of 5 micrometres cannot pass through. The mask however does have a lower effectiveness in blocking dust and fine dust, about 55%-80% as effective in blocking dust, but since it is built to be waterproof and block droplets, the was could be seen as being 99% effective in blocking the droplet based viral transmissions.
However, the even more surprising part is that even though it is splash-proof, the mask is also easy to breath through. Unlike the standard health mask that consists of 3-4 layers of filters and non-woven fabrics, this anti-droplet masks usually only consists of 2-3 layers. There are 2 layered versions which solely consists of a combined outer and filter layer followed by an inner layer, and there are 3-layer versions with another filter layer in between. Like the surgical masks, the rectangular shaped masks are often double layered while the ones with a more defined outward shape are usually 3 layered. In addition, the outer layer being a lightweight non-woven fabric to block droplets, which in turn allows the mask weigh less than 2/3 of a standard health mask.
Since the KF-AD mask came out as an alternative to the surgical masks, the AD mask’s effectiveness in blocking droplets is similar to the surgical one. Both masks have the KF55-80 blocking rate, but the standard health masks include the KF certification index, while the AD masks mostly focus on the droplets blocking portion. The other difference is the shape. The surgical/dental masks are only often available in the rectangular shape, but the AD mask is also available in a more three-dimensional shape to prevent events of the mask being hitched up when being wrapped around the cheek and keep its shape over the face.
Masks are generally structured in a 3-layered structure, the outer, filter and the lining. But depending on the layers of filters, it could go up to 4 and 5. When comparing the masks under a 30x magnifying optical microscope the KF-AD masks has small gaps between the fiber to promote easy breathability, but the filter is still dense so that it blocks droplets from passing. The KF94 on the other hand has a quadruple structure, and the outer and linings shows up with tighter fiber gap than the KF-AD masks. When comparing the filters under a 1000x magnifying electron microscope both masks were densely structured enough without any significant differences in effectiveness. However, the KF94 mask does have 2 filters as opposed to 1.
Blocking Fine Particles
KF94 > KF80 > KF-AD, Surgical
Ease of Breathing
KF-AD, Surgical > KF90 > KF94
Based on the chart above, I think it would be better to use different masks for different situations. First and foremost, if you are caring for a patient or person who is suspected of having COVID-19, it is unconditionally recommended to wear a health mask of a grade of KF94 or higher. KF80 is recommended for people in the risk group, such as the elderly, pregnant and chronically ill or for those who have underlying health issues (chronic lung disease, diabetes, blood cancer, patients taking immunosuppressants, etc). However, if you have trouble breathing for any reason the KF-AD mask might be the better choice. The KF-AD mask would be a good option for healthy people who need to wear a mask for an extended period of time or when doing outdoor activities. It is also recommended to wear the KF-AD mask in hot summer months or in humid/rainy/snowy environments.
By Sue Kim
Product link: KF-AD Korean Face Masks
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