CDC: Masks with Valves are Worthless
Face masks equipped with exhalation valves might look cool, but they’re pretty much worthless when it comes to stopping the spread of the coronavirus.
That’s according to the Centers for Disease Control and Prevention, which points out that regular masks stop transmission by serving as a barrier; so any openings in the barrier defeat the purpose.
The CDC says cloth masks with no openings are much better choices. That’s not to say valved masks are completely useless.
They prevent wearers from breathing in foreign particles while allowing them to exhale freely — making them more suitable for construction work, according to the CDC.