Fabric masks

26 April 2020 by Jennifer

Why I’m now wearing a home-made fabric mask when out & about, and related facts.

There’s been a lot of discussion about the question of whether wearing a home-made cloth mask can protect you from catching the new coronavirus.

How much it protects you is missing the main point, though. It’s much more likely that wearing a mask in public protects other people from being exposed to some of your germs, when you breathe out or cough. As the slogan has it, “my mask protects you, your mask protects me“.

Smiley white person with short hair (me!) wears a fabric mask across mouth and nose. The mask fabric is dark blue with a curly pattern of white flowers, lines and dots. Text says "My mask protects you / Your mask protects me".

Logically, it makes sense to catch as much as possible of the stuff where it comes out of a human (i.e. primarily their mouth & nose), and reduce the risk of little bits of virus drifting off to other places.

It probably does reduce your own COVID-19 risk at least a little bit, though.

Anything else that helps you to not breathe other people’s breath is good too, hence the recommendation to keep your distance from other people. Soap destroys the virus, hence the recommendation to wash hands before touching nose, mouth, eyes etc.

If you’ve worn a mask, it’s best to wash your hands just after taking it off – in case it did save you from someone else’s germs arriving on you, and now has virus on it. Then either wash the mask, or leave it for a few days before you wear it again. If you can catch the virus off objects (which I think is not a major transmission route, going by research I’ve read about), at any rate it’s said not to survive for long on fabric – perhaps a day or so.

How it works

A key point is that in order to be useful, a cloth mask doesn’t have to block things as minuscule as the virus itself. That’s because the virus mostly travels by hitching a ride in tiny droplets of liquid that come out in your breath or in a cough. (Think of the cloud you might see when you breathe out in cold air.) Those “tiny” droplets are pretty giant compared to the virus itself, so can be caught by fabric which wouldn’t catch 1 virus alone.

So if you see people saying “the gaps in the fabric weave are bigger than the virus”, that’s probably true – but it doesn’t mean the fabric isn’t helping. If it’s catching the damp droplets before they evaporate, it’s catching virus at the same time.

Most DIY designs have at least two layers of fabric, so even if a droplet happens to get through a tiny gap in one layer, it won’t necessarily get through the next.

On the safe side

But is it completely proven that this kind of mask helps? Why do people say the evidence is inconclusive?

You can assess here some of the science on what home-made fabric masks can do.

At a later stage of the epidemic, it may be clearer exactly how helpful it is for people to wear fabric masks out & about, and what the limitations are.

(One current research question is whether the amount of virus you breathe in can make a difference. It may be that if you get only a tiny tiny amount initially, it gives your immune system a better chance to respond. In that case, even reducing the amount of virus you breathe in could save your life. This seems to me pretty plausible.)

But meanwhile, it’s an example of asymmetric risk. The “precautionary principle” says that in a situation like this, where (a) you don’t yet have all the definitive info, (b) the down side of guessing wrong would be big, and (c) there’s a “safe side”… it makes sense to “be on the safe side“.

So you don’t necessarily wear a mask because you’ve definitely proved it helps. You might wear a mask because logically, it probably helps, and because the cost & trouble of it is tiny compared to the trouble, pain & cost of someone getting seriously ill.

Why aren’t we already

You might be wondering why, if it’s such a sensible thing to do, it isn’t already everywhere!

A lot of countries actually have made masks-in-public a rule now, and there’s already been discussion of that happening in London.

As to why it hasn’t happened here yet, I think this is basically down to misinformation and misunderstandings (as well as the UK government generally dragging their heels compared to other countries).

  1. The World Health Organisation and some other places advised originally that masks wouldn’t help the general public.

    I’ve seen it suggested that this was an intentional fib because they didn’t want ordinary people buying the medical masks, which were in short supply. (Though if so, they could’ve just explained the shortage, and asked us to make the fabric ones, as indeed people have been doing!)

    Alternatively, it may simply have been based on flawed reasoning (see points 2 & 3).

  2. It took time for people to shift their thinking. A lot of earlier research & debate about masks was completely focused on questions of: how much does it protect the person wearing it? In those terms, there are obvious drawbacks to a home-made fabric mask (or even a soft medical mask like dentists wear), such as for instance the fact that it doesn’t cover your eyes. People had to rethink, and reassess the evidence in terms of protecting each other.

  3. Some people have been thinking of it as a binary question, and concluding “These could let some of the virus through, or round the edges, so they’re no good!” – rather than thinking “Even if this type can’t bring the risk to zero, they can still reduce it, and that’s worthwhile”.

  4. There’ve been suggestions that face masks might give people a false sense of security, or might lead to people touching their faces more. As far as I know, there isn’t evidence that either of those factors would outweigh the benefits.

  5. Some UK advisors seem to have started with a mistake about how the virus spreads. Some official information wrongly advised that you’re not infectious till the time when you have symptoms (e.g. when you start a fever or a cough). In reality, infectiousness is already high just before you start symptoms – when you don’t know yet you’ve got it! It makes sense to wear a mask and keep your distance even if you feel fine, in case you caught it already and you don’t know yet.

Where to get a mask

What if you think this is a good idea, but you don’t yet have a mask to use?

Firstly, here’s an 8-minute video showing a couple of simple DIY methods, no sewing. One method uses a T shirt, with scissors to cut it into a shape. The other uses cloth folded over, and hair ties (or rubber bands, though those won’t be as comfortable). If your bit of cloth is already about the right size, you might not even need scissors for that one.

Secondly, loads of people are making them now, and selling them via places like Etsy or eBay, or giving them away via local networks.

Thirdly, here’s a method for people who are OK with sewing, including a pattern which you can either print, or copy onto a grid.

That pattern was the basis of the one I’m wearing in the pic, though I’ve slightly changed it since my first prototype.

I don’t think the “where do I get them” problem will last long, anyway; shops will be trying to stock them as soon as they can, and makers will be inventing beautiful designs. I look forward to seeing people’s creativity!

The weirdness

Of course, one of the obstacles to this catching on is that at the moment, it’s still kind of weird to wear something over your face as you’re walking down the street.

So, what can we all do to help to shift the norm, so that wearing a cloth face covering in public is normal?

  1. If you feel able to, then start now to help set the trend, and wear one :-)

    Bear in mind that this is socially much easier for some people than for others. In particular, I feel it’s on white people to make a start, especially confident white people who haven’t been bullied, and/or don’t mind looking weird. The more people do it, the less weird it will be, and the less difficult (and in the case of racism, potentially risky) it will be for everyone else.

  2. Support businesses & organisations which are taking the lead. Prioritise shops where the shop assistants routinely cover their mouths & noses. Prioritise shops which insist their customers do the same. Tell them why they won your custom. (And prioritise the shops which are using other sensible adaptations to assist physical distancing as people come & go.)

  3. If you feel able to, communicate with businesses & organisations which are lagging behind. Let them know you want them to go in this direction.

  4. If you have crafty skills, make some cool & beautiful masks!

More on the science

Couple more excellent resources, which appeared during the days I had this blog post on the back burner…

Smiley white person with short hair (me!) wears a fabric mask across mouth and nose. The mask fabric is dark blue with a curly pattern of white flowers, lines and dots. Text says "My mask protects you / Your mask protects me".