As the world continues to battle the pandemic, we thought we should help you figure out what kind of mask is good for you, but first, let’s get to basics. Why is the Coronavirus so dangerous.
The coronavirus is a new virus, which means our immune systems have never encountered it before. It’s different from the seasonal flu, which most of us have some protection from, either because of previous exposure to related influenza viruses or because we got a flu shot. An estimated 25 percent of people with coronavirus feel perfectly fine and don’t know they are infected and could be contagious. And guess what? You could very well be one of them! That’s why you should wear a mask to protect other people from your stealth germs.
So…how can your mask could protect others.
Even a simple mask is very effective at trapping droplets from your coughs and sneezes. Humans exhale contagious droplets and aerosols constantly. A study showed that when an infected person wore a mask, it blocked nearly 100 percent of viral droplets and some of the aerosol particles they had sneezed or coughed.
But…How is my mask protecting me.
Remember, any face covering is better than no face covering. While some people are experimenting with homemade masks using air filters and vacuum bags, the average person doesn’t need that level of protection if you’re practicing social distancing and leaving the house only for essentials. Given that there is so much variability in fabrics, the best advice is to start with a light test. Hold the fabric or mask up to the light and see how much light gets through. The tighter the weave, the less light you’ll see, and the more protection you’ll get. Test the fabric over your face to make sure you can still breathe through it, though.
T-shirts: Most of us have an old T-shirt we could cut up into a no-sew mask. It’s one of the most convenient fabrics to use, but there is a lot of variability in how well T-shirt material performs in lab tests. At the Virginia Tech, a single-layer of an old cotton T-shirt captured 20 percent of particles down to 0.3 microns. It captured 50 percent of particles down to 1 micron. A 2013 University of Cambridge study tested two layers of T-shirt which captured about 70 percent of particles down to 1 micron.
Cotton quilting fabric: This is the high-thread-count cotton fabric preferred by quilters for its durability. In studies at Wake Forest Baptist Health, masks made with quilting fabric rivaled the filtration efficiency of surgical masks.
Tea towels: Tea towels became a popular source of mask material after an August 2013 study from researchers at University of Cambridge found the material compared well to a medical mask at the 1 micron particle size. The study authors did not note the brand. The towel used was not terry cloth, but the tightly-woven absorbent tea towel variety.
Pillow cases: Pillow cases are a good option for sewers who don’t have other fabric. In the 2013 study, 2 layers of pillow case fabric tested close to the efficiency of a surgical mask at the 1 micron standard, but in a study at Missouri University of Science & Technology, it took four layers of 600-thread-count pillow case material to achieve that level of protection at the 0.3 micron standard.
Coffee filters and paper towels: The C.D.C. suggests inserting a coffee filter into your mask for extra protection. Missouri University of Science & Technology scientists found that using three coffee filters made it difficult to breathe. Adding a layer of paper towel in between two layers of fabric could make your homemade mask more efficient. An engineer at an air purifier firm ran his own test and found a single paper towel filters 23 percent of 0.3 microns and two paper towels filtered 33 percent. We added a paper towel to our homemade T-shirt mask.
Scarves and bandannas: When it comes to ease of use, you can’t beat a scarf or bandanna to cover your face. But bandannas are thin and, even folded over four times, don’t offer much protection. Scarves may be better but can be thick and hot. Both are better than nothing.
Filters and vacuum bags: Scientists trying to find effective alternatives for medical workers have cut up layers of air filters and tested HEPA vacuum bags. Both can work quite well, but both have significant downsides. Air filters, when cut up, can release fibers that can be dangerous to inhale, so the filter material should be sandwiched between layers of heavy cotton fabric if used in a mask. Vacuum bags are good filters but not that breathable. Plus, some brands of vacuum bags may contain fiberglass so should not be used to cover your face.