If you’re wearing "cloth facemasks" with a little plastic valve embedded in it or a traditional face mask, 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 facemask.
Why are face masks with valves compromised?
In the age of COVID-19, we wear masks when out and about for two reasons: First, we hope they might protect us from other people, at least a little bit.
The second reason is more significant: they protect us from infecting others if it turns out we are infected and don’t know it.
Valves defeat that second purpose. A valved mask is letting your breath out unfiltered; the valve acts as a little escape hatch for any virus-laden droplets you’re breathing out. Some municipalities that require masks have specified that masks with valves do not count. You also won’t typically see valved masks in healthcare settings for the same reason. As the CDC explains:
respirators with exhalation valves should not be used in situations where a sterile field must be maintained (e.g., during an invasive procedure in an operating or procedure room) because the exhalation valve allows unfiltered exhaled air to escape into the sterile field.
Cloth facemasks or N95's?
If you have a stash of N95s that you previously used as dust masks, or if you’re considering buying a designer cloth mask that has a valve (somehow the fancy ones all seem to have valves), be aware that they only filter your inhaled air, not your exhaled air. And right now, that’s not good enough.
Example of N95 like mask style with valve
Many people are opting for the new style "cloth facemasks" to add some color to their outfit with a range of designs and finishing options.
As the saying goes, “your mask protects me, my mask protects you,” so please use a valve-less mask to do your part in reducing transmission.