how long does a disposable P2 mask last?

Working in a dusty environment, floor tiles possibly asbestos (trying not to disturb those though).

How do I know when to sling the mask?

when you notice dirt on the inside. you do realise it wont offer sufficient protection against asbestos?

Anything from a few minutes to a few months depending on what you are doing with it. It won’t protect you from asbestos though. It probably won’t actually protect you from anything. When I carry out face fit testing at work around 70% of users fail the test due to not wearing and adjusting the mask correctly, it being the wrong shape of mask for their face, or having any amount of facial hair. Even a 5 o’clock shadow can make the mask useless.

Hope that helps!

<slight hijack> So is there anything that works reliably, (even for beardies) or am I doomed to dusty lungs?

how long does a disposable P2 mask last?

They’re disposable – thats the clue, expect to get through several a day. I prefer to use the 3M ‘semi-disposable’ ones which you could get a month’s work out of and have a decent amount of sealing and adjustment.

They seam a bit pricy at £15 but they’re much better value than the diy store ones at £3-5 a pack of three, which is only enough masks for a morning’s work and they don’t work anyway (given the same useless masks sell for £10 for a box of £100 for commercial users)

So is there anything that works reliably, (even for beardies)

There are various whole face respirators, usually with a little belt mounted, battery powered pack with filters, although some have that fan/filter integrated into the head bit – the benefit of them for beardies is they seal around your whole face, rather than just around your mouth/nose

Comically, even with organic vapour filters fitted, if you fart the fan sucks it up and blows it straight in your face.