New York Post - Experts share which masks are most effective against new COVID-19 strain
KN95s or KF94s
Aaron Collins, a Minnesota-based mechanical engineer, who wrote his master’s thesis on the science of aerosols and calls himself a “citizen scientist,” has been reviewing masks on his YouTube channel since August.
Collins turned his bathroom into a makeshift lab, using an aerosol generator to pump out tiny particles of salt and water. A condensation particle counter counts how many particles are in the air and how many are in the mask Collins is currently testing. He compares the number of particles inside the mask with the number outside of it, which helps him determine its effectiveness.
His best bets, he found after his research, are protective masks such as KF94s, KN95s or N95s.