The best easy-to-find material for a homemade face covering to protect against coronavirus transmission is four-ply microfiber cloth, according to Army researchers at the service’s Combat Capabilities Development Command.
Researchers with the command’s Chemical Biological Center said in a Wednesday news release that the four-ply microfiber cloth, which can be found in the cleaning section of most big box stores, filters out more than 75 percent of particles.
An N-95 mask, the protective covering in short supply among hospital workers who need it most, is able to filter out 90 percent of particles, they said.
Layering a polyester bandanna can filter out about 40 percent of suspended particles, the release added. Officials from the command did not immediately respond to a request for comment asking how well the neck gaiters perform, which are commonly worn by soldiers.
The team made the determinations after testing more than 50 materials — with more tests ongoing — by spraying a salt aerosol at a piece of the chosen material.
The salt particles used to test the filter were 0.2-0.3 microns in size. Coronavirus is roughly 0.1 microns in size, but the virus floats around in droplets expelled by infected persons that are anywhere from 0.2 to a several microns in size or larger.