Medical Masks, A Purchasers Field Guide

A guide to procuring your own mask during the COVID-19 pandemic

April 4, 2020 Author: Becky Kaufman- Seattle, WA

The CDC recently recommended that all people wear a medical mask in public in an effort to slow the spread of COVID-19. (1) There is a national shortage of medical grade masks and the most effective ones are logically being reserved for medical professionals and first responders in their fight against this deadly virus.(2) So, what’s best for the general public? Since it is very un-likely you will be able to find a medical grade mask online, you will have to find a different resource.

How do you decide what’s best? Let’s first look at the materials that comprise the coveted N95 respirator mask. (3)
It is made with three non-woven layers:
• Filter- Polypropylene
• Shell- Polyester
• Coverweb- Polypropylene

Due to the fact that polypropylene is becoming scarce to the increasing demand, (4) what is the next best choice for your mask? There are many news articles, conflicting professional opinions, and an abundance erroneous information on social media. Here is a list of materials that have been scientifically tested, in order of percentage of efficacy: (5)
• CDC approved Respirator N95 Mask- they are the most effective against acquiring virus
• Vacuum cleaner bag- although works well, is very stiff and uncomfortable
• Two layers of pillowcase fabric/tightly woven cotton and 100% cotton t-shirt fabric
-the t-shirt fabric providing the best fit

In a recent unpublished study by Dr. Scott Segal, chair of anesthesiology at Wake Forest Baptist Health in Winston-Salem, North Carolina, Dr. Segal recommends -"quilters cotton" with a thread count of at least 180, and had thicker and tighter weave. Lesser quality fabrics also worked well, as long as they had an internal layer of flannel. You do want to use a woven fabric, like batik," Segal said, "but you don't want to use a knit fabric, because the holes between the knit stitches are bigger." (6) Additional information from the University of Florida says that a “two-ply spun polypropylene that cannot be penetrated by water, bacteria or particles. It blocks 99.9% of particulates, making the masks about 4% more effective at blocking particulate material than the N95 masks, according to Bruce Spiess, M.D., a professor of anesthesiology in the UF College of Medicine, who made that calculation based on the manufacturer’s specifications.”

Understand that a homemade mask will not 100% prevent you from contracting COVID-19. “A protective mask may reduce the likelihood of infection, but it will not eliminate the risk…” (7)

How do we decide which style works best? There are many styles available on the market- pleated, shaped, plain rectangle, single layer, double layer, ones with pockets for filters, etc. In the 2013 study cited above, a mask that works the best is the one that you will wear. Your mask must be comfortable and easy to put on for you to want to wear it. While masks with ties keep the mask snug to the face better, the masks with ear elastics are easier to use.

Three Layered Cotton mask by Period Corsets

A fabric face mask can be enhanced with a pocket for inserting a non-woven filter that aids in keeping the virus from passing through the fabric. There are different kinds of filters that are aid in filtering virus. Some suggestions out there on social media and in the news have been to use non-woven materials like blue hydroknit shop towels,(8) coffee filters, (9) HEPA filters(10) - (not recommended (11), and most notably polypropylene. (12) If you remember, polypropylene is used in the manufacture of the N95 respirators.

Pleated Mask with pocket for removable filter, made by Period Corsets

It is advised that masks be washed after every use and the filter be replaced.(13) You may want to have a stock of the masks and filters for the essential worker in your life who leaves the house on a daily basis. In these days of social distancing, you probably won’t need a mask every day. Using basic math and the idea you should not be leaving the house, and you go out once or twice a week for a couple months, one or two washable masks and two dozen filters per person will probably suffice. Do not share masks! (14)

Have extra filters on hand to switch out after each use Above: Period Corsets mask with extra polypropylene filters — Have extra filters on hand to switch out after each use
Above: Period Corsets mask with extra polypropylene filters

After aggregating all this information, it seems like the “perfect” mask does not exist for the average person however, a mask made from woven 100% cotton, with 180 or greater thread count, enhanced with pocket for a polypropylene filter, and fitted with ties- is a suitable mask for the average person on the street. However, ear elastics may give the wearer more incentive to actually wear the mask out of the house!

These masks can be purchased from many vendors on Etsy.com. Etsy, a place best known to offer amazing handcrafted items, has now become a resource for handcrafted non-medical masks.

See Period Corsets Selection of masks for sale here!

This all said, there is NO SUBSTITUTE for social distancing. Wash your hands. Be healthy and safe.

What is a medical mask? World health organization