When it comes to mask filters, "the size of the filter seems to matter," says Weaver, who co-authored a recent study on the topic in the journal ACS Nano. Choose a filter that spans the material of ...

As the CDC changes its guidelines to recommend more heavy-duty masks, this scientist explains what's behind the difference in quality of cloth masks, surgical masks, and N95s—and how to make ...

Cloth masks Filter large particles If both an infected person and an uninfected person wear cloth masks and are within six feet of each other, it can take just 27 minutes to transmit the virus.