In New York City, you must wear a face mask when going out. The masks I’ve seen can be characterized in a number of ways: utilitaritarian—some version of a surgical or N95 mask, fun—a homemade or Etsy-bought cotton mask with a print, or improvised—repurposed eye masks, bandanas, and scarfs. All-in-all they filter out appropriately 30% of droplet particles flying around in the air. Recently, scientists have explored ways to make our masks more effective. And their findings are simple tweaks to what we are already doing.
Here’s how to boost your face mask’s ability to block out particles, according to science.
1. The Pantyhose Method
Researchers at Northwestern University found that adding a nylon stocking (think pantyhose or tights) over your facemask can help improve its effectiveness in two ways: filtering out particles and improving the mask’s fit. According to NPR, this method creates a tighter seal between the mask and the wearer’s face making “a homemade cloth mask match or exceed the filtering capability of medical-grade surgical masks.”
Cloth masks tend to filter out about 30% of aerosol particles. The pantyhose method was found to increase that capability to approximately 80%. Researchers also found that it improved 3M and N95 medical masks which tend to block out 75% of particles. Add the pantyhose method and it increased their effectiveness to 90% and 95%, respectively.
How do you put it to use? Take a pair of pantyhose or tights and cut off a leg and the toes. Put your face mask on then slip the leg over your head and position the fabric over your face mask so it covers your nose down to your neck. See here:
2. The Cloth Combo
If you’re crafty enough to make face masks (I am not) then consider this: a combination of cotton and either natural silk or chiffon can effectively filter out particles. One caveat: the mask must fit well.
University of Chicago researchers determined that cloth-combo by blowing aerosol particles across various fabric samples. The best cloth face mask recipe:
1 layer tightly woven cotton sheet + 2 layers polyester-spandex chiffon = 80%-99% particles filtered out
The aerosol particle size determines that blocking stat, but this is close to the effectiveness of N95 mask material.
Why does this cloth-combination work? The tightly woven fabrics (in this case the cotton) act as a physical barrier while the chiffon acts as an electrostatic barrier, meaning it has energy that particles need to overcome to pass through.
If you don’t have these exact fabrics in your stash, there are effective substitutes: For the chiffon, natural silk or flannel can be used. Or, you can simply use a cotton quilt with a cotton-polyester batting, as it worked the same.
Ultimately, no mask will protect us 100% which is why behaviors like social distancing should be done with or without a mask.