Facemasks

They can be washed and sterilised under a proper UV lamp or the microwave on low power.

Would leaving them in quarantine for 72 hours allow reuse to save money and avoid sending them to landfill?

on 09/07/2020, Scott supposed :

Pay a little more and buy washable ones, wash and dry overnight.

Surely disposable ones should be suitable for incineration. Except of course that the greenies have their knife into that as well.

I see they're now beginning to say that face masks may protect the wearer, which is what I've been arguing for a while, whereas previously they said they just protected other people from the wearer's snot, spit etc. If a mask protects other people, then surely it also protects the wearer. These filters aren't just one-way things!

On high filtration masks (N95 or better) washing will often destroy the electret material's charge generation properties, and that will disable the masks ability to capture the medium sized particles.

IIUC They can be cleaned, but it requires a special process rather than normal washing.

The obvious answer is yes, as long as they hold together.

Chris Hogg brought next idea :

Well I can understand that principle...

You cough without a mask and it flys all over the room. You cough wearing a mask and the mask catches most of it.

What does get out, whether wearing or not wearing a mask, can get to the face and the eyes even of someone wearing a mask, plus spreading to the clothes of anyone in range. The mask only protects the lower face from the virus.

Wearing a mask will obviously provide the wearer with marginal protection, better than nothing. Which is why masks ought to be absolutely compulsory for everyone making near contact with anyone else. You wear the mask for the most part for the protection of others, not oneself.

The ones I've just got from CPC say "machine wash at 30° and then tumble dry"

The trouble is that the only reason most people wear masks is because they mistakenly think they protect the wearer.

GB explained on 09/07/2020 :

Exactly, that's why it needs to be compulsory. A few on buses are deciding not to wear them, deciding they are not that bothered about the risk of getting the virus - but it is not themselves they are putting at risk, so much as everyone else on the bus - those doing the right thing and wearing a mask.

Hmm...you may be right. I wasn't aware that you could catch it via eyes, but a bit of Googling reveals that it is possible, apparently.

Chris Hogg laid this down on his screen :

Hands too, or any part of the body which can come into contact with the face, mouth, nose or eyes. Which is why hand washing is so important and face screens for those coming in close contact.

What particulate size do they go down to?

(more to the point, are these surgical (i.e. designed for egress filtering, and protection of others) or respirator style (designed for ingress filtration and protection of the wearer)?

In fact, they are, or at least they are certified only one way. Surgical face masks are certified as to the level of particulates they allow out, while respirators (aka dust masks) are certified as to the level of particulates they allow in.

Depends on the type of mask...

Actually, many of them are - by design. For example the very good 3m half mask respirators I use for dust and vapour protection are valved, to reduce the fatigue on the wearer. That however means that exhaled air passes straight out the valve, bypassing the filters. (and now in a fairly directional jet as well)

A surgical mask however is good at capturing droplets expelled by the wearer and so protecting those around from the wearer. However their face seal is rarely good enough to give fully effective ingress filtering, and also they don't protect the mucus membranes of the eyes. So while its likely they will offer some protection to the wearer as well, that's more of a fringe benefit.

I counted 14 people of the local station platform not wearing coverings.

Nicola says shop staff are not responsible for enforcing the rule. Friend of mine says she will wear one as she enters the supermarket then take it off unless and until she is challenged.

AFAICS there's nothing to stop one combining the two. I suspect wearing the surgical mask over the valved respirator is likely to be more comfortable but also more likely to attract attention/comment than vice versa. But I thought I'd leave the gathering of empirical data to better/bigger/braver than me :)

For some reason I can't manage with any other type - my specs and/or safety specs just fog up.

I have to resort to contact lenses when I'm out shopping - couldn't cope with the admiring glances a half mask would attract.

I've tried the various internet remedies without success.