Aerosol and Air Quality Research
“…General masks, regardless of their material, showed little protection against the tested aerosols, even when they had a fancy brand name (i.e., Best Nano, Ultra Antibiotic, Anytime Guard, Hygiene).
Handkerchiefs demonstrated very little protection against the tested aerosols. Penetration was over 95% when tested with the KFDA protocol, decreasing to 87–91% when three and four layers were used.”