By Ellen, 6th Grade

We’ve seen, (and worn) it all. Surgical masks, cotton masks, bandanas, K95s, homemade masks, masks with valves, and a whole lot more. But what is most efficient?

Wearing a mask is crucial to stopping the spread of Covid-19, as well as protecting yourself and others. “Surgical masks and cloth coverings can reduce viral transmission by 70% if everyone wears them and wears them correctly over [their] nose and mouth,” says Purvi Parikh, a clinical assistant professor at the Department of Medicine at NYU Grossman School of Medicine. It also reduces the risk of asymptomatic spread. According to the CDC, an estimated 50% of transmission happens before people develop any Covid-19 symptoms. Since masks are critical in protecting against the virus, it is important to learn more about different types.

Clinical or N95 masks are in low supply. Masks with valves are not recommended by the CDC, because although it protects the wearer, it is unhelpful for others, letting out unfiltered air. So, what masks that follow these guidelines will give a good barrier to the virus?

While N95 masks provide a high level of protection, they aren’t a realistic option for most people, because of their low supply. So, most people turned to homemade masks or simply tying a bandana as a mask. It is not the most efficient. Bandanas offer little more protection than no mask.

Duke University physics professor Martin Fischer did a test, and it turns out that the bandana was so thin it actually put more respiratory particles in the air than the test with no mask at all. Martin explains “We attribute this to the fleece, the textile, breaking up those big particles into many little particles. They tend to hang around longer in the air. They get carried away easier in the air. So, this might actually be counterproductive to wear such a mask. So, it’s not the case that any mask is better than nothing.” Best to wear a fabric homemade mask.

A team of researchers claims to have found the best materials for homemade face masks. Apparently, a combination of either cotton and chiffon or cotton and natural silk appear to effectively filter droplets and aerosols. Silk stays water resistant despite repeated cleaning and can be immediately reused. It is antimicrobial, antiviral, and antibacterial because of the copper, put into the fabric by the animals. The second option: chiffon. One layer of a tightly woven cotton sheet combined with two layers of polyester-spandex chiffon filtered out most aerosol particles (80-99%, depending on particle size), close to the efficiency of N95 mask material. In conclusion, the researchers say that tightly woven fabrics like cotton can act as a barrier to particles, whereas fabrics like certain types of chiffon and natural silk serve as an electrostatic barrier—even better protection.

A note about masks. To function effectively, masks should be worn over the nose and mouth. In addition, the CDC guidelines state that a cotton mask has to have at least two layers, meaning there are less gaps in between fibers. One teacher at The École wears homemade masks: two layers of cotton or a cotton blend fabric with space to add a filter. Also, to have a protective mask, make sure it has a tight fit. A 1% gap reduced the filtering efficiency of all masks by half or more!

Avoid touching the front of your mask – that is where all particles are trapped. You should rotate and clean your masks regularly. Ms. Millan, who uses public transport often, says “I wear my Air Queen Nano Mask when I am on the subway. When I get to work, I usually change into a cloth mask. I do this because it is a little more environmentally friendly. It allows me to reuse the Air Queen Nano Mask for about a week, instead of using 1 or 2 new ones daily.”

All of this will hopefully help you in the future of mask-searching and mask-making!