- For the mask itself, use tightly woven fabric that will withstand the heat of sterilization, like 100% cotton twill or denim. Good quality, heavy weight quilting fabric is also excellent. Canvas or duck fabric may be good too.
Examples: high thread count (300 or 400) sheets; men’s oxford shirts; some curtains; turn your old jeans or Dockers twill pants into shorts, and use the legs to make a mask!
- The rule of thumb is: ““Hold it up to a bright light,” said Dr. Scott Segal, chairman of anesthesiology at Wake Forest Baptist Health who recently studied homemade masks. “If light passes really easily through the fibers and you can almost see the fibers, it’s not a good fabric. If it’s a denser weave of thicker material and light doesn’t pass through it as much, that’s the material you want to use.”” Prewash fabric in hot water to preshrink it. Do not use scented detergent, fabric softener, or dryer sheets. Material must come from a nonsmoking home.
- For the ties, 1/4″ elastic or ties made out of cotton bias tape, cotton ribbon, or 1.5″ strips of knit fabric cut across the grain are good.
- For nosepieces, Twisteez wires are most highly recommended and they have special pricing for Covid-19 groups!
If you are unable to obtain Twisteez, try double wire clips from the tops of coffee bags and bread bags, doubled pipe cleaners with the ends bent over to protect the nose, or better yet: soft, wrapped wire ties used for staking plants.
- Disposable filters: UPDATE!! DO NOT USE AC filters or HEPA vacuum bags. Explanation below. For masks worn by ordinary people in public, try a simple rectangle of tissue paper, paper towel, or coffee filter (any nonwoven fabric that is easy to breathe through). For masks to be worn by essential personnel, people have tried interfacing, surgical wrap, and blue shop towels. However, there have been some concerns about breathability, as some users have complained that it is hard to breathe through these materials. When in doubt, try it out for a few hours. If you can’t breathe through your filter, essential workers can’t either. We DO NOT recommend HEPA filters or AC filters, which may contain fiberglass or other dangerous fibers.
This information will be updated as we find out more about how other materials, such as surgical wrap or blue shop towels, really perform in practice.
from “Humboldt County on Alert” FB group: FILTER INFORMATION FOR MASKS IMPORTANT (FILTERS): We have had many posts suggesting the creative use of pleated filter material extracted from a 3M Filtrete Air Filter. For safety’s sake, we contacted 3M today and talked with them about this material being incorporated into a face mask. They strongly stated that the air filter material should NOT be used for this purpose. This material is specifically manufactured by their construction division for use in a furnace, and it should never be incorporated into personal protective wear. Since 3M also makes the N95 masks, they are experts on what materials are safe and healthy for face masks. Additionally, their Material Safety Data Sheets for Filtrete warns: “Use or processing of the product not in accordance with the product’s recommendations or not under ordinary conditions may affect the performance of the product and may present potential health and safety hazards.”
Additionally, materials used to manufacture HEPA vacuum cleaner bags contain glass microfibers which are very harmful to lungs and should NOT be used.
If you would like to include filters with your masks, some safe options are non-woven products like non-fusible interfacing or charcoal re-useable washable filters (Amazon). On the other hand, testing has proven that the simple insertion of folded tissues or paper towels into the masks greatly improve its effectiveness without inhibiting the breath-ability of the mask.