PSA time.

In my quest to learn everything I can about masks and their protective abilities I ran across this article and it really jives with what I know, suspected, and believe.

If you’re wearing a face mask with a little plastic valve embedded in it, you should know that valves compromise the effectiveness of the mask—and this is true whether your mask is a hardware-store N95 or a designer cloth mask.

These valves allow exhaled breath to bypass the filter. When you breathe in, the air you breathe is being filtered by the mask; when you breathe out, it is not. (The valve only operates in one direction.)

One-way valves make sense if you’re kicking up sawdust in your basement, walking around California during wildfire season or working in a factory where particles you definitely don’t want to breathe in may be in the air. In these cases, the mask’s job is to protect you. The valve makes it more comfortable to wear so you can get through your day or your factory shift without feeling too stifled. 

Full article here.

 https://vitals.lifehacker.com/if-your-mask-has-a-valve-its-half-useless-1843182019?utm_source=lifehacker_newsletter&utm_medium=email&utm_campaign=2020-05-01

 https://tinyurl.com/yamwbwps

So basically, these valved masks protect YOU (inhaling) but don't protect others if you exhale germs and stuff.  Ever see doctors wearing valved masks?  Hmmmmmm.