Other DIY Mask Material Resources
Berkowitz, B & Steckelberg, A 2020, Washington Post.
"The coronavirus is extremely tiny — too tiny to be trapped by most fabrics that still allow air to flow through them. However, the virus seems to be most transmissible when it is stuck to much larger water or mucus droplets that come out of our mouths and noses when we cough, sneeze or talk, and a homemade mask can block those droplets."
Ben Schott, Bloomberg
"Not all materials provide the same protection, even if something is better than nothing."
Wang, J & Du, G (2020), Irish Journal of Medical Science.
"The particles in a bio-aerosol are generally 0.3 to 100 μm in diameter; however, the respirable size fraction of 1 to 10 μm is of primary concern. Bio-aerosols ranging in size from 1.0 to 5.0 μm generally remain in the air, whereas larger particles are deposited on surfaces."
Much more professional testing results from TSI directly. This site's particle filtration results will be more accurate.
Breathability results shouldn't be impacted as performance can be viewed by relativity to an n95.
Goldberg, C, 2020, WBUR.
"New infections diagnosed in Brigham and Women's employees dropped from 12 or 14 a day to more like eight once they all had to wear masks — and to about six once patients had to wear masks too."
By Chris Holmes
Masks like these may provide additional surface area for materials that are harder to breathe through.
Konda, A, Prakash, A, Moss, G, Schmoldt, M, Grant, G, Guha, S 2020, American Chemical Society.
Their experimental apparatus consists of an aerosol generation and mixing chamber and a downstream collection chamber.
Davies, A & Thompson, K 2018, Disaster Medicine and Public Health Preparedness.
This study includes pressure drop across fabric. [PDF]
Provides a mask pattern that allows filter inserts such as a filti layer, or another safe material to breathe through (safe air furnace filters?).
Thomas NG has a great list of online resources for DIY PPEs.
Getting Personal Protective Equipment (PPE) to Our Healthcare Heroes.
