N95 Masks and "Surgical" Masks

In this part of Ontario, there are no masks of any type available in retail outlets. Discouraged, I checked a box of assorted masks in my home shop, and was surprised to find a couple of N99 masks (a higher particulate filtration rating than N95's). I use one for brief grocery excursions. Check your home shop cupboards - you might not find N95 or N99 masks, but any mask is better than no mask.

Did you find the N99 hard to breath through if you have to use it a long time?

I don't use it for a long time - maybe 20 to 30 minutes in the grocery store. I don't find the breathing resistance objectionable -but then, I've always had a good set of bellows (lungs). Was an avid skin diver back in the day.

There are paper masks that have a plastic release vent on the front , they are easier to breathe through

see 3M 9322

there are many higher grades of filtration than N95

If you want to get really fancy use a full face mask with CBRN / NBC filters , there is evidence the virus can infect you through mucosal membranes so keep your eyes covered

N 95 masks may be difficult to breathe through, but if you get sick from not wearing one then your problem is solved and you won't have to worry about wearing them anymore.

Yesterday I saw a video on YouTube, medical personnel were hanging their masks inside shipping containers and sanitizing them with UV-c, the light in combination with produced ozone kills viruses.

As for the wearing of masks, I noticed politicians and news organizations not using them, although all of the members of the medical teams were. I figured what was good for the goose was good for the gander, regardless of the difficulty of breathing through them.

Typically the mask is to protect the wearer from inhaling dangerous or toxic substances. Fit to the face is critical in achieving effective filtration. Facial hair that extends across the edge of the mask makes them worthless. Professionals all know these things.

When I was grinding paint (lead free) off a swimming pool surface I used a mask with an exhalation valve and wore it for 6-8 hours a day for the 3 days the work required. Also kept the surface damp or wet with a thin film of water to cut down on the total dust in the air. Without the exhalation valve the moisture in the exhaled air rapidly fogs glasses and goggles to render vision impossible.

But remember, the intent of protection is against inhaling something harmful. However, masks without the valve that are properly fitted will provide protection both ways.

--JMM

The reason for wearing a mask in the current situation is not just to protect the wearer from breathing something harmful, as is asserted in this thread. An equally important reason is to protect others. This virus is known to be spread asymptomatically - you could have it for up to three weeks, and not realize you are infected, and during that time be spreading it to others. If you are wearing a mask, if you cough or sneeze, the mask will contain the fine spray of your virus bearing saliva from being carried in the air to others. Also not mentioned in this thread is that a mask prevents you from touching your face around the mouth and nostrils - something people do surprisingly often, without awareness of the action. So mask protection is not entirely related to air filtration for the wearer. Even a home-made, unrated mask will prevent the described face touching, and will contain, if not all, at least a large portion of your saliva droplets if you cough or sneeze, reducing the viral load broadcasted to anyone nearby. So, as I wrote earlier, any mask is better than no mask.

I'll go along that general line, but "you could have it for up to three weeks, and not realize you are infected" is a bit too long. It's more like "97.5% of those who develop symptoms will do so within 11.5 days (CI, 8.2 to 15.6 days) of infection."

https://annals.org/aim/fullarticle/2762808/incubation-period-coronavirus-disease-2019-covid-19-from-publicly-reported

That is why I wear a mask when I am at work or where other people are, like the grocery store. Not to protect myself, but to protect others in the possibility that I might be carrying the virus without any symptoms.

The duration is not a meaningless quibble to the epidemiologist, as it affects the modelling of the future epidemic. I am merely pointing out that the "certain time period" is shorter than you suggest. I will also point out that social distancing, keeping 2m away from anyone else, is far more effective than wearing a mask. As public health may become a matter of enforcement, even in the land of the free, it will be interesting to see how various measures become enforced

I am in favor of the 'social distancing' mask - a cloth mask for the necessary shopping etc. A reasonable cloth barrier is a stopgap for the failures of physical distance (or droplet compliance with the 2 m limit). It will likely catch stray droplets and prevent them from direct entry to your mouth or nose - which is the main portal for infection no doubt about that. Likewise the effect on your own droplets going out, it will greatly reduce the risk of droplets traveling more than 2 m. The velocity at that distance may be not enough to propel the hypothetical droplet through the barrier, much less so if it's already slowed down on the breather end. So the net effect of everyone wearing simple masks would be significant.

I agree that N95's are just not suitable for shopping. Hated these or similar masks in the shop. Very hard to breathe and steaming up the glasses when the seal isn't right. I tried a couple of face mask designs and found one I like. Surgical style does not fit well even made in soft cloth. It's right up against your mouth and the fit around the nose is not good. I haven't tried the real PPE surgical mask but I believe it's about the same. Another popular mask style was better fitted but with stitching on the front - I just don't trust that. Space between stitches is way bigger than pore size of a decent cloth, and so is any hole made by a sewing needle. The only one I like is the 'camp style' - solid piece of cloth folded and stitched down for fit around the nose and chin. Comfortable and enough of a pocket to breathe into.

The point of a 'distancing' mask is not the same as PPE where you are faced into a fountain of infectious droplets no more than 2 ft away. It has to be good enough to stop your own droplets or seriously slow them down, and ideally to also stop/catch incoming droplets from a distance of 2 m or so. It also has to be comfortable enough that you can breathe well and not need to tweak it during the trip. Easy to remove and handle the decontamination steps.

The perfect seal is is not for us mortals. It's for nurses and doctors in the ICU. When I put on my mask to adjust the fit, I'm not trying to entirely seal it, I'm thinking, where is the air going to force itself out - where do I want that to happen. Better from the sides than up through the top where it gets your glasses. And just make sure to adjust you're getting enough air intake for whatever you have to do, so you don't have to handle the mask again until you're ready to take it off.

Check this out, great images of coughs in a mask.

https://royalsocietypublishing.org/doi/full/10.1098/rsif.2009.0295.focus
A schlieren optical study of the human cough with and without wearing masks for aerosol infection control
Penn State Julian W Tang Oct 2009

I think it's prudent to take precautions, but within limits. I live in the Los Angeles area and the spread of CV here has been minimal - not even close to when a flu hits. 11391 cases in the entire Los Angeles County area and 495 deaths. We have 10.04 M people in the county, so a 1% infection rate would be 100.4K - we're barely at 11% of a 1% rate or 0.11%. I know there are many people who are not doing a great job "social distancing" When I go to the taco shop, there are people walking by each other - more intent on getting their food than worrying about CV. I went to the grocery store and saw the same thing. And the auto parts store. And the hardware store.

Initially, I think people want to be safe, but we go back to normal behavior when other emotions pop up. This being the case, why do we have so few cases?

Someone mentioned that we may have already had CV pass through CA in December/January. I know quite a few people who were very sick in those months - some taking 6 weeks to recover. Body aches, coughing, sneezing, fever ... And remember that we have lots and lots of Chinese people living here - many travel back and forth to China. And there are our businessmen who also travel to China. And of course we have people who vacation in China. We have much more of this than the rest of the country, so logically, there's a good chance that CV has already been here.

I don't know the answers, but I think some very unsound practices have popped up. We're so worried about CV that we've lost track of common sense. Close down hiking trails and beaches, so people can sit at home and become obese and depressed?

A couple weeks ago, I walked down my street and saw four for lease signs in a row. All the stand alone buildings have a for lease sign - 100% of them. I drove down the main street in town - more and more for lease signs are going up. The other day, I was driving by a town 15 minutes from here and I saw an office space lease sign for $450/month!

I am very, very worried that our economy has gone down the tube. I don't think the average person understands that there's a very good chance that they're not going to have a job when we get the "open the economy" call.

It's going to get very ugly folks. I hope everyone reading this has their finances straight, because it may just be worse than 2008!

Autobroker: At my grocery store, NE Ohio, maybe half the people were wearing masks. I sorta go by the philosophy to build up your immune system and then don't worry too much about it. And a lot of building up the immune system happened when we were kids.

Lehman57 - I'm going to gladly give you a GA, because you make so much sense.

I like your idea about building the immune system. We were exposed to a lot of things when we were kids - so good for us as adults! I also take a heaping teaspoon of 100% vitamin C in a glass of OJ. I do this when I have the feeling I'm catching something. One heaping teaspoon is what it takes to get me to vitamin C saturation.

I'm glad to see that you were able to go to your grocery store (hopefully without waiting in a long line to get in) and that there are many people who aren't falling for the media's CV job.

AB: My grocery is doing a good job. No lines to get in, short or no lines at the cashier. Plastic shields at the cashier and a few other places. Distance marks on the floor, but I think they are closer to 8 or 10 feet instead of 6. Aisles were made one-way. The hot-food bar has been closed, but stocking is nearing normal levels after being pretty sparse when the shelves were stripped. (But I found what I needed even if different brands and sizes.)

Our grocery store has started raising prices. They know the public will pay whatever price they put on items, so they're going up!

And still, there's no TP or paper towels, hand sanitizer, bleach, very little cleaning products, meat section has lousy cuts, produce was picked green and fresh seafood sure doesn't look fresh. And worst of all, the only bacon I see is Oscar Meyer - it's really junky bacon.

Now the profiteers take hold!

The whole point of the current coronavirus scare is that nobody, but nobody, builds up a lasting immunity to everything in advance. Whatever you built up as a child in the way of resistance to bacteria is now completely irrelevant. This virus is new to humans, and entirely new antibodies have to be generated.

I wear an N95 for 12+ hours per day and have not experienced any issues with breathing although I will admit that it does get hot under that thing. We do, at times, add a procedural mask over the N95 to preserve the life of the mask. This practice is not really recommended but when supplies are limited we must adapt. Even with the additional covering mask my breathing is fine. I believe that when this is all over with a lot of us will have stronger lungs then before, at least for a while. Also it has worked as a pretty good smoking deterrent for one coworker.