Discussion about use of Valved Masks

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Specializes in Occupational Health; Adult ICU.

Valved masks work very well at reducing moisture and heat inside the mask and does help to reduce glass fogging. However, they are essentially a 3/4" HOLE where exhalation occurs. This, in effect concentrates the outflow of breath without any filtration/capture at all. Worse it can increase the velocity of exhaled air, especially if the wearer should sneeze or cough.

Here’s some articles on why one (especially a nurse) should NOT be wearing a valved mask:

Heuvelmans, 4/29/2020. Sure, wear a mask. Just not one with a valve

Skwarecki, 4/30/2020. If Your Mask Has a Valve, It's Half Useless

Moffitt, 5/4//2020. Why your N95 mask could endanger others

Kekatos, 4/28/2019. Bay Area says masks with valves are not acceptable face protection amid the coronavirus pandemic because they allow your breath to escape and endanger those around you

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Specializes in Private Duty Pediatrics.

Can the valve be taped over? The wearer could still breathe out through the mask, just not through the unfiltered valve.

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Specializes in Occupational Health; Adult ICU.
On 5/24/2020 at 10:03 PM, Kitiger said:

Can the valve be taped over? The wearer could still breathe out through the mask, just not through the unfiltered valve.

I doubt tape would hold. Sure the area between the latex flap valve and the cover could be filled with epoxy or hot-glue.

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Specializes in Pediatrics.

Thanks for bringing up the topic--I have been wondering about this! (Can someone fix the links to the articles? I'd love to read them!)

My hospital has given us 3M model 8511 respirators with valves (to be used up to 33 times before getting a new one). These do not protect patients from the wearer's exhalations, which does not seem ideal (but beggars can't be choosers).

Meanwhile, people purchasing face masks online have the option to purchase 'cycling masks' or 'dust masks' which also feature valves. Since the whole purpose of wearing a face mask in public places is to protect OTHERS, it seems to me these masks with valves are less than ideal as well. They will stop the majority of big droplets (I guess?), barring sneezes and coughs. I am also guessing that anyone who sneezes wearing a cotton face mask would be blowing a lot of that sneeze out past the cotton mask as well. I wish we had a robust public health department that would address this and put out some good public health education material on masks.

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Specializes in Psych, Addictions, SOL (Student of Life).

One has to understand the difference between the two types of N-95 masks. Medical grade masks were meant to be worn for short periods and changed often. Construction grade masks are used for tasks that produce a high level of particulate such as painting or sanding and are designed to be worn for several hours at a time. The vent is to allow for keeping the wearer cool. As is noted by other posters the outgoing valve is not filtered to prevent the wearer exhalations from exiting the mask. If the primary purpose of wearing a mask is to protect others from your potentially infected breath wearing a vented mask serves no purpose.

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Specializes in Psych, Addictions, SOL (Student of Life).

Just today when I went to an appointment at my physician I was asked to put a paper mask over my valved walking around town mask.

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Specializes in Occupational Health; Adult ICU.

Read on a safety forum:

"I attended a CDC webinar on Masks on July 6. The speakers were Dr John Brooks, CMO - COVID-19 Response and Dr Michael Bell, Dep Director CDC. When asked the question about masks with exhalation valves the response was:"

"Make sure there is no exhalation valve; it focuses the exhaled aerosol into a “rifle shot”

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