This author has no business writing on this subject if she can't even get the basic terminology correct. There's a difference between a mask and a respirator. T

This author has no business writing on this subject if she can't even get the basic terminology correct. There's a difference between a mask and a respirator. To over simplify, one deflects and one filters. Masks don't have valves, respirators (sometimes) do. A valved n95 respirator is essentially acting as a respirator (filter) while inhaling, and as a mask (deflector) while exhaling. Calling valved respirators half useless implies that masks are wholly useless. Neither surgical masks or cotton/other homemade masks (or valved respirators) are designed to filter exhaled breath; in fact, most of the air goes around surgical masks, but droplets hit and stick to the mask based on the same principles of bugs hitting a windshield. And that's all they're designed to do- retain/deflect droplets/particles expelled by the wearer. Valved respirators still do this. Even the tiny gap in the open valve usually is filtered, just not to n95 levels. Of course all of this presumes the user is using the PPE correctly in the first place. If you don't know the difference between a mask and a respirator, I can almost guarantee you're using yours wrong.