Question: Coronavirus & home sewn masks?

How To Stop Face Masks From Fogging Up Your Glasses

https://www.forbes.com/sites/rachel...ks-from-fogging-up-your-glasses/#6aa930b12e6a

 

Good tips!

I've also seen a suggestion to use some sort of tape (something that won't hurt your skin, like the tape that you use with old gauze bandages, or maybe even a band-aid) to tape the mask to your nose under your glasses.

 

Wondering if breathing on them before you put them on works in this case - I think it's recommended for swimming goggles.

 

I thought I would just post a picture of the home made mask I bought for when I need to go out. It’s Marie from aristocats. I got a galaxy one for my mum. They’re both a cotton type of material, 3 layers on each.

 

So cute

 

Adding A Nylon Stocking Layer Could Boost Protection From Cloth Masks, Study Finds


https://www.npr.org/sections/goatsa...-boost-protection-from-cloth-masks-study-find

 

So, I went to my sewing box this evening to see what fabric I had - very little, it turns out, as I think most of it is in storage. The only piece I have is a long strip of cotton which is about an inch (aka 2.5 cm) narrower than a standard disposable surgical face mask, so I assume that's not really going to give enough lateral protection. Do you think I can machine-stitch 2 pieces together to make it wide enough (bearing in mind that I also need to make a lot of pleats), or would the seam be a weak point, virus ingress-wise?

 

Here's a question: I have a few of the surgical masks. A few weeks ago, a social worker I know told me these are only good for 4 hours and then should be tossed. This morning I washed a number in very hot water and soap and they are now air drying. I actually wear a surgical mask, and then on top of that I have a cloth mask which I have sewn which provides a nice tight fit. So here's the thing: are these surgical masks still effective when washed?

 

I don't know of any data on that and there probably is none. But I think you can be pretty sure that unless you can see through them more they will still prevent a high proportion of virus particles getting into public space if the wearer speaks or coughs. As to whether or not they would protect the wearer I think that is much more doubtful but if it were me and the only option I would still wear one.

 

Check out Ian Lipkin's interview*; they were investigating whether washing masks at "56 degrees centigrade for 30 minutes" would be enough.
I assume this is based on the following data from WHO [https://www.who.int/csr/sars/survival_2003_05_04/en/]
"Virus survival in cell-culture supernatant

• Only minimal reduction in virus concentration after 21 days at 4°C and -80°C.
• Reduction in virus concentration by one log only at stable room temperature for 2 days. This would indicate that the virus is more stable than the known human coronaviruses under these conditions.
• Heat at 56°C kills the SARS coronavirus at around 10000 units per 15 min (quick reduction)."

Personally I'm not sure why they are looking at 56 degrees centigrade for washing masks --- why not heat them to a higher temperature (say 74 degrees) for a shorter period of time?

I hadn't noticed the stability of the virus at 4°C (fridge temperature!) "Only minimal reduction in virus concentration after 21 days" @Jonathan Edwards
Anyone got reliable data for stability of virus on food e.g. fruit such as pears! I might be peeling them after reading the above data, regarding the stability of the virus, from WHO!

Interview with Ian Lipkin:
51.30 minutes
56 degrees for 30 minutes
*http://www.microbe.tv/twiv/twiv-special-lipkin/

 

Well, that's vaguely what I've been wondering for weeks. If, as recommended, I were to bag it immediately after wearing, but then leave it for, say, a good couple of weeks to see whether I develop any symptoms and nothing happens, presumably I could assume that either I didn't have Covid and therefore there are no contagious germs on the mask, or there are, but they've evaporated or whatever they do in the meantime. Presumably any moisture on the mask will have dried out by then. Is there really any reason why you shouldn't re-use it in a casual situation like just being outside? Is there a flaw in my reasoning? I must admit that it had never occurred to me to risk washing them, because I didn't think they would withstand it.

 

Yes, that occurred to me in the wee hours of the morning, when I was lying there unable to sleep. I think I can probably remember how to do them after my Home Economics teacher drummed it into me decades ago. Existing garments would be mainly of the T-shirt type, I think, and therefore less useful than a cotton weave. Alternatively an old pillowcase or something, but those are usually polycotton, which again might not be as good.

 

I think Lipkin is addressing a different issue from the one @Perrier raises. If there is virus on a mask washing in hot water may kill the virus but the mask may no longer be any good as a filter. That would certainly be a worry for some of the disposable materials. I don't see it as much of a worry for shirt material. On the other hand I agree with @Wits_End that there doesn't seem a to of logic in washing masks. I am not washing the one I have used whenever outside in public for a fortnight or so.

 

Putting my biologist hat on for a moment, I agree that air drying for several days could be a good alternative to washing, and that re-use of medical masks should then be safe. And it seems this is backed up by the various tests done on materials and virus survival.

However the concept of “bagging” masks up concerns me. Leaving the masks in a plastic bag might prevent them drying fully, and so allow other nasties to grow. So the masks are probably best left unwrapped (or wrapped in a fabric bag), so that mould or bacteria don’t get a chance to grow in the damp!

 

couldn't you do them in a microwave oven?
https://regenexx.com/blog/coronavirus-episode-12-does-a-microwave-kill-coronavirus/

eta:
I was thinking, wash it with soap etc and then put in a bowl while still wet and nuke it in the microwave(?)

 

This a Blue Peter, don't try this at home one!

Take a saucepan of water at 74 degrees centigrade and an electric slow cooker. Place mask on the base of the slow cooker and put the saucepan on top. Turn on the slow cooker. Maintains the heat at about 74 degrees centigrade for a while i.e. to try to kill the virus.
We don't have results of tests which kill the virus at different temperatures, so we don't know if this works.