Let me preface this by saying I have no medical training nor do I claim to make masks that protect you from COVID-19. I am simply a seamstress with a clothing company that has been making face masks with filters for 2 weeks and this is a summary of what I have learned.
It was the wee hours of March 21, 2020 and I couldn’t sleep. The day before, I wondered aloud “should I be making face masks?” and here I was, the answer was yes, and the anxiety was high. How was I going to do this? Once my husband and I started the research, there was no going back. My brain was racked with ideas and thoughts-what do I need to make masks? Where will I get the supplies? What’s the best pattern to use? Do they actually work?
Here is what I learned…
Now, of course I can’t find the article about the filtration effectiveness of different fibers that I found in those wee hours of the morning, BUT I do know that 2 layers of cotton are better than nothing against a droplet born pathogen, like (currently) COVID-19 is thought to be. After talking to some doctors at the local hospital, I learned that this virus is only airborne when an infected body is opened up, as in the case of intubation, etc. The N95 masks are most effective in this scenario because they are air tight against the skin, however…N95 filters out 95% of particles, so I guess there’s no 100% effectiveness anywhere. Also…the shortage of N95 masks is alarming and should be going to medical workers first and foremost, as they are on the front lines, risking infection on a daily basis.
With a droplet born pathogen, the thing to avoid is the spread of droplets (sneezing, coughing, spit talking), which wearing almost any kind of fabric over the face will do. After listening to the 60 minute talk from Dr. David Price, I learned that also covering your nose and mouth will help you avoid touching your face, which is how you ultimately contract this virus-by touching something contaminated and then touching your eyes, mouth, nose. Also, I gotta say it-WASH YOUR HANDS!
Mask effectiveness is improved with a filter, which brings me to the debate on filters. Medical masks are made from a few layers of material, and usually include a melt blown fiber layer as a filter. After many hours of research on melt blown fabrics, I was pulling my hair out. There are SO many different kinds because it’s a process of making fabric, not a particular fabric itself, does that make sense? There’s melt blown fabric used for interfacing (used for making fabric structured in sewing), for shade cloth (in gardening), for wedding aisles, and a whole lot more. Since I couldn’t find any melt blown fabric that had any research done on it’s ability to filter particles, I decided not to use this and stick with air filters.
A lot of people were suggesting the use of HEPA filters, but, turns out, most HEPA filters are made from microscopic glass fiber, which you definitely don’t want to be inhaling. We found and decided to use the Filtrete material from 3M, which is used in air filtration systems, and were able to get MERV 13. MERV 16 is the best, filtering out particulate matter up to .3 microns, but it’s very challenging to get in large quantities-especially now…plus, it’s more expensive.
If you can get your hand on air filters from a hardware store, all you have to do is remove the plastic framing and use the fabric that is sandwiched inside. Look for a MERV rating of 13 or higher. In a recent New York Times article, I learned Dr. Wang, an assistant professor of environmental engineering at Missouri University of Science and Technology, found that including 2 layers of this air filter material in a mask can filter out particles up to 94%, so that’s what we’re using. Each mask you buy from RevivALL Clothing, will have 2 layers of MERV 13 rated fabric included that can be replaced with your own filter material. Now, please don’t ask me how long a filter is good for, I have no idea.