N95 Masks with Valves and Covid-19

[Andrew Joiner]

I'm not a medical pro. My experience with masks has been for dust and fumes. The valves emit drips on rubber respirators. I assume the valves on paper N95 masks exhaust your breath and any virus you may have.
I was surprised to see that the CDC says N95 Masks with Valves are OK for medical workers. Since you can have Covid-19 without symptoms this surprised me.

This is from the CDC:---
An N95 respirator with an exhalation valve does provide the same level of protection to the wearer as one that does not have a valve. The presence of an exhalation valve reduces exhalation resistance, which makes it easier to breathe (exhale). Some users feel that a respirator with an exhalation valve keeps the face cooler and reduces moisture build up inside the facepiece. However, 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.----

Am I missing something?

[Greg Funk]

The N95 masks are meant to protect the medical workers and they appear to do that regardless of whether they have a valve.

Masks are not intended to allow infected medical workers to continue working. They have other means of ensuring the health care workers are not infected.

[roger wiegand]

In normal times when there are plenty of masks around I'll bet CDC would not recommend them. This week they are better than nothing, and will protect the wearer.

[Tom M King]

A lot of what I see the medical pros going to work in looks like wishful thinking to me. I forget what country it is that has had no sick medical people, but they have totally enclosed suits. I hope our people have them next time.

[Wade Lippman]

You are certainly right, valves allow an infected person to spew virus. BUT, if you have to wear them all day, the ones without valves are really brutal. The ones with valves are bad, but without even worse. Its a trade off.

[Mike Cutler]

I'm not a medical pro. My experience with masks has been for dust and fumes. The valves emit drips on rubber respirators. I assume the valves on paper N95 masks exhaust your breath and any virus you may have.
I was surprised to see that the CDC says N95 Masks with Valves are OK for medical workers. Since you can have Covid-19 without symptoms this surprised me.

This is from the CDC:---
An N95 respirator with an exhalation valve does provide the same level of protection to the wearer as one that does not have a valve. The presence of an exhalation valve reduces exhalation resistance, which makes it easier to breathe (exhale). Some users feel that a respirator with an exhalation valve keeps the face cooler and reduces moisture build up inside the facepiece. However, 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.----

Am I missing something?

Andrew

No, you're not missing anything.
Every year, since 1984, I have had to take annual courses and exams to wear a "respirator", including the 3M, N95, "dust mask" you refer to. I also have to perform a mask fit test, annual physical, and a "PFT", Pulmonary Function Test.(Lung capacity.) This allows me to wear everything from that 3M mask to an SCBA, Self Contained Breathing Apparatus. (Scuba tanks) Also including PAPR's and PAPH's. Air fed, full body suits.
The dust mask is "better than nothing". Having said that though, it still is a nice product. I like them and use them all the time at home.

[Jim Koepke]

We went shopping the other day wearing 3M N95 dust masks without the valves. Candy had to take hers off because she couldn't breath with it on. It was difficult for me, but not bad enough that it had to be removed:

Dust Mask.jpg

A few People asked me where they were found. They were bought a few years ago for use in my wood shop.

jtk

[Andrew Joiner]

We went shopping the other day wearing 3M N95 dust masks without the valves. Candy had to take hers off because she couldn't breath with it on. It was difficult for me, but not bad enough that it had to be removed:

Dust Mask.jpg

A few People asked me where they were found. They were bought a few years ago for use in my wood shop.

jtk

Yes Jim. That's a problem for me too. Same with the face coverings I've made and masks/ respirators I have. Without valves breathing is tough. I can't imagine working hard all day without a vent.
I have several face covers I've made. Some are thicker and more sealed at nose, but hard to wear for longer than a store trip. The thinner ones I use to prevent me transmitting virus if I'm a non-symptomatic virus carrier. I wear that outside when i'm with my great grandson.

[Andrew Joiner]

Andrew

No, you're not missing anything.
Every year, since 1984, I have had to take annual courses and exams to wear a "respirator", including the 3M, N95, "dust mask" you refer to. I also have to perform a mask fit test, annual physical, and a "PFT", Pulmonary Function Test.(Lung capacity.) This allows me to wear everything from that 3M mask to an SCBA, Self Contained Breathing Apparatus. (Scuba tanks) Also including PAPR's and PAPH's. Air fed, full body suits.
The dust mask is "better than nothing". Having said that though, it still is a nice product. I like them and use them all the time at home.

Thanks for the verification Mike.

[Mike Cutler]

We went shopping the other day wearing 3M N95 dust masks without the valves. Candy had to take hers off because she couldn't breath with it on. It was difficult for me, but not bad enough that it had to be removed:

Dust Mask.jpg

A few People asked me where they were found. They were bought a few years ago for use in my wood shop.

jtk

Jim

I use the model with the valve because the model without tends to cause my glasses to fog up more.
I have also had very good success with the RZ masks, but I expect that they may no be any easier to get at this time, than the 3M's. They are $30-$40.00 each, so maybe Amazon has some?????

[Kev Williams]

--the valves in these masks are simple anti-backflow valves WITH a filter. When inhaling the valve is closed, blocking any incoming particles. When exhaling, the valve opens. The valve is still effective because any virus that may make it to the valve has a very high probability of getting stuck to the valve's filter due to the moisture in your breath. And any virus or other particles that may still get thru , the valve directs exhaled air downwards. And since the valve is small, the air speed of your breath will increase (venturi effect) as it passes thru the valve, literally blowing any particles downward towards the ground. Very effective as a 'citizen' mask. However, unlike being out in public, the patient a doctor is operating on is right in the line of fire of the exhaust valve, so they're not usable in an OR...

(disclaimer- I didn't read any of this anywhere, just my 2c based on common sense engineering principles )

[Jim Koepke]

I use the model with the valve because the model without tends to cause my glasses to fog up more.

This has been a problem for me until yesterday. Before putting the mask on yesterday morning, the aluminum nose clip was bent over my finger. That worked so much better than my previous method of pinching it on my nose. It actually kind of surprised me that my glasses didn't fog up in the cold morning air while waiting to enter the grocery store.

jtk

[Bill Dufour]

Our governor does not wear a mask for his press conferences.
Bil lD.

[Brian Elfert]

--the valves in these masks are simple anti-backflow valves WITH a filter. When inhaling the valve is closed, blocking any incoming particles. When exhaling, the valve opens. The valve is still effective because any virus that may make it to the valve has a very high probability of getting stuck to the valve's filter due to the moisture in your breath. And any virus or other particles that may still get thru , the valve directs exhaled air downwards. And since the valve is small, the air speed of your breath will increase (venturi effect) as it passes thru the valve, literally blowing any particles downward towards the ground. Very effective as a 'citizen' mask. However, unlike being out in public, the patient a doctor is operating on is right in the line of fire of the exhaust valve, so they're not usable in an OR...

I have one of the 3M N95 masks with exhalation valve. There is no filter on the exhalation valve.

This type of filter might help the wearer, but doesn't protect the public if you are unknowingly a carrier. This is a common saying about masks: "My mask protects you. Your mask protects me." The gist of the saying is that you wearing a mask protects others, not yourself so much.

[Jim Koepke]

Our governor does not wear a mask for his press conferences.
Bil lD.

In the few pressers seen of Governor Newsom it seems he is not in a room full of people. Governor Coumo is often in a room with other people but they often seem to be more than 6' apart.

jtk