I have been concerned that face masks for non-first-responders would shift vital protective resources away from first-responders and that would give some people a false sense of security. As a physician, I think the time has come to put those concerns aside.
For those of you staying at home who might be considering performing CPR, a tracheostomy, or intubating someone in the neighborhood [1], an N95 mask is a necessity; otherwise, you are diverting "war-time" supplies from the first responder and health care army.
The Centers for Disease Control and Prevention (CDC) just announced they are temporarily suspending work by lab scientists in BSL-4 (aka biosafety level 4) facilities. They recently learned their current stock of air hoses that  attach to the protective suits worn by staff have not been certified for breathing air.