[slab_happy]

[Whoops, this got posted before it was finished.]

Because as of today, government advice is officially that people should "wear a face covering in enclosed spaces where social distancing is not always possible and they come into contact with others that they do not normally meet, for example on public transport or in some shops", and because I sew and one of my best friends is a serious quilter and the crafting community is nerding out hardcore on the materials science and limited research and thus I know a lot more about nonwoven polypropylene than I did a week ago -- I thought I would dump what I know.

The scientific evidence re: fabric masks is that they're better than nothing, basically: https://www.researchgate.net/publication/258525804_Testing_the_Efficacy_of_Homemade_Masks_Would_They_Protect_in_an_Influenza_Pandemic

The one big plus of a cloth mask is that you're not wearing a surgical mask or respirator that a health or care worker needs way, way more than you do.

Hard to evaluate exactly how effective they can be because it varies a lot by fabrics and by design, and efficacy probably drops a lot if they've been worn for a while and become moist. And the materials that filter better for aerosols tend to be much less breathable, predictably enough.

Materials nerding: https://www.nytimes.com/article/coronavirus-homemade-mask-material-DIY-face-mask-ppe.html

They have to be used correctly, including being washed after every use and donned/doffed correctly:

https://twitter.com/JustinMcElroy/status/1247619269451448325

They don't give you any excuse to let up on social distancing etc. -- they just might cut the risk in circumstances where that isn't possible. One of the primary reasons why there's been debate over recommending fabric mask use is that some scientists are worried that they'll make people feel safer than they are and thus behave in a riskier manner.

Their major usefulness seems to be in preventing you from infecting other people via droplet transmission, rather than protecting you from other people.

If you want to buy some, my rec is to get on Etsy, I kid you not, because the crafters are knocking them out very affordably.

Basic requirements are at least two layers of tightly-woven fabric, preferably with a bendable wire over the bridge of the nose -- this allows you to stop a lot of the gaping you otherwise get, making the mask more effective and also stopping your glasses from misting up.

But there's new research coming out quite fast (e.g. some wild stuff on the effectiveness of hybrid masks including several layers of chiffon for electrostatic filtering), so the picture may change and we'll probably know more about how to make them even better than that.

[tomtom]

Any recs \ egs from esty.

[tommytwotone]

Heard same on R4 the other day - masks are primarily to stop / lessen risk of you (if you're asymptomatic) passing it on, rather than you protecting yourself.


2 ply of anything seems to be the minimum requirement, used once then washed.


I went down the hoodlum route and bought some bandanas:


https://www.bandanashop.com/


Only downside is that when I go to Sainsbury's it looks like I'm about to jack the place, not buy some coconut milk and The Guardian.

[Wood FT]

Heard same on R4 the other day - masks are primarily to stop / lessen risk of you (if you're asymptomatic) passing it on, rather than you protecting yourself.


2 ply of anything seems to be the minimum requirement, used once then washed.


I went down the hoodlum route and bought some bandanas:


https://www.bandanashop.com/


Only downside is that when I go to Sainsbury's it looks like I'm about to jack the place, not buy some coconut milk and The Guardian.

I find a balaclava is really practical as my bandana kept slipping down. People are really respectful of social distance too, they even lie down. Such strange times.

[duncan]

This may repeat some of the above but it's a good summary of the science I think from very reputable authors: https://www.fast.ai/2020/04/13/masks-summary/

Summary: DIY masks are worthwhile if you're altruistic.

[slab_happy]

This may repeat some of the above but it's a good summary of the science I think from very reputable authors: https://www.fast.ai/2020/04/13/masks-summary/

Summary: DIY masks are worthwhile if you're altruistic.

Also if you're selfish, because wearing one normalizes mask-wearing and encourages other people to wear them, thus protecting you.

(That's a great summary, thanks for linking that!)

[slab_happy]

Any recs \ egs from esty.

Nah, sorry, been making my own.

But look for stuff fitting that description (and consider grabbing a couple so it's easier to keep them washed).

Some people are using a layer of non-fusible interfacing because it's non-woven polypropylene and may have effectiveness as a filter -- we don't have good data yet. Some people include a pocket for a disposable filter -- also unclear. The pleated designs might be better than the ones with a seam down the front (because a sewn seam inevitably involves lot of tiny holes).

The things that are definite and that probably cover the basics: multiple layers of tightly-woven fabric, best possible fit with minimal gaps at the edges, USE IT CORRECTLY. For example, the best mask in the world won't do shit if -- like the gentleman I saw taking a walk the other day -- you wear it over your mouth but not your nose ...

Handy guide to some DIY no-sew options: https://www.theguardian.com/us-news/2020/apr/06/how-to-make-no-sew-face-mask-coronavirus

[slab_happy]

I find a balaclava is really practical as my bandana kept slipping down. People are really respectful of social distance too, they even lie down. Such strange times.

I've heroically resisted my impulse to make one in the shape of a plague doctor mask. So far.

[tommytwotone]

Surely you could mod a Jason from Halloween-style ice hockey mask for similar effect?

[Bonjoy]

Could this be the end of the great beard revival? In a work context I've always been told facial hair renders mask wearing pretty pointless as it greatly compromises face fit. The access company I work for operates a 'clean shaven policy' for this reason, as do many large construction sites. 

[winhill]

This may repeat some of the above but it's a good summary of the science I think from very reputable authors: https://www.fast.ai/2020/04/13/masks-summary/

Summary: DIY masks are worthwhile if you're altruistic.

It's about the best that anyone has come up with but it's from Masks for all which is a sort of pressure group run by the authors, Trish Greenhalgh and Jeremy Howard (data guy who funded it). TG has been in various spats with people for a month trying to get masks adopted but she's backed out of some debates she's been in, especially when faced with experts in other areas (like behavourism, where much objection has come from).

The main problem is that masks get filled with virus, then handled and the virus is then spread. WHO, PHE, SAGE have all ignored her, which she's been a bit snarky about) and CDC said that the best way is still 2 metres but no virus filled mask.

Similar to BoJo's document today. Although even TG says people need better training in handling dirty masks, although she'll see that as vindication. The funny thing is TG made her reputation writing about evidence based medicine and now she's saying we need more narrative and anecdote.

[slab_happy]

Could this be the end of the great beard revival? In a work context I've always been told facial hair renders mask wearing pretty pointless as it greatly compromises face fit. The access company I work for operates a 'clean shaven policy' for this reason, as do many large construction sites. 

I'd think that even with a beard, a mask would give you decent protection against spraying droplets horizontally over other people, which is the most important function of a mask in this context. Where it's going to compromise you is re: what you're inhaling.

I know some folks have been working on mask designs that fit better round beards, though.

[slab_happy]

and CDC said that the best way is still 2 metres but no virus filled mask.

I mean, yeah? I've not seen anyone arguing that cloth masks mean we can/should stop social distancing, but they do potentially cut transmission in contexts where perfect social distancing isn't possible to maintain. E.g for all the poor fuckers who are being expected to get back on the Tube to go to work this week.

From the CDC: https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/diy-cloth-face-coverings.html

CDC recommends wearing cloth face coverings in public settings where other social distancing measures are difficult to maintain (e.g., grocery stores and pharmacies), especially in areas of significant community-based transmission.

Also the multi-disciplinary group convened by the Royal Society:

https://www.theguardian.com/world/2020/may/04/scientists-disagree-over-face-masks-effect-on-covid-19 -- decent piece summing up the debate

especially when faced with experts in other areas (like behavourism, where much objection has come from).

Yeah, the concerns are that people won't know how to use masks correctly and/or will get sloppy with social distancing because they feel safer. Which are legit worries.

But right now, I feel like — the horse has exited the stable. A lot of people are having to go into situations where perfect social distancing is not possible. We’re going to need to try to cut transmission by any means possible, so better to teach people how to use masks correctly (and work out how to make the best ones possible).