A face mask designed for one thing may not work for another

Scam: There's no such thing as a washable P2/N95 or PM2.5 mask. Beware of false claims.
Scam: There's no such thing as a washable P2/N95 or PM2.5 mask. Beware of false claims.

If you've watched any international motorsport, or been outside in a hotspot area, you'll have seen all sorts of different mask designs.

Some of those designs may have also been originally intended for another purpose.

In order to comply with lockdown laws or local recommendations, a mask for COVID-19 simply needs to hinder your moist breath from travelling too far from your face. Its main purpose is to minimise the chance of you spreading the virus to other people.

To achieve this, you can use a variety of masks, even home-made ones, so long as they're not too thin and don't have a functioning exhalation valve (or on P2/N95s with one, you've taped the valve shut).

In terms of securing them, pandemic masks don't need a clever design, unless your job requires you to flap your jaw with it on.

Some teams have gone with surgical-style creations, occasionally in team colours, whereas others seem to have decided they should be more like a muzzle.

The problem is, and you'll have noticed this yourself, is many designs are only secured behind the ears and not over the head, so those drivers and team managers have to keep pulling the mask back up over their nose every second word, or learn how to speak with their teeth clenched. Nobody seems to care though. They're wearing a face covering and that's enough for the authorities to let them use real race tracks.

What worries me though, is masks being sold with false claims about the filtration.

For DIY projects and moderate levels of bushfire smoke, the masks you will need are meant to protect you and your lungs. These worksite masks are rated differently to filter out different size airborne particles. Bear in mind also, that only specialist respirators will filter out carbon monoxide.

If you are caught short with a bushfire, even the old recommendation of a damp cloth might help you survive if you can also avoid succumbing to CO poisoning. But to avoid long-term lung damage from the tiny airborne particles in smoke, you need the correct mask for the situation.

The industrial masks with a P1 rating are designed to filter out mechanically-generated particles. P1s (without a valve) will also be fine when the law or health recommendation says to wear a mask in public during a pandemic too, but they don't filter vapours for you, nor do they filter the tiny damage-causing particles in smoke.

Genuine P2 and N95 masks are rated to filter out tiny particles like those found in smoke, as small as 0.3 microns (the air quality monitors you can check online measure down to 0.25 microns, referred to as PM2.5).

You probably read stories about these P2/N95 masks last summer, so heed that advice and get the proper rating, and get them before everyone else suddenly clears the stores out of their stock. Oh, and gents, shave that fuzz off your face because you need a proper seal all the way around in order for the P2/N95 mask to actually do its intended job.

What I'm actually concerned about are cheap masks falsely claiming to have a P2, N95 or PM2.5 rating. In particular, I'm looking at washable cloth masks with a replaceable filter that slips in. Since they're multi-layered and similar to home-made designs, these fakes will actually, even without the filter element put in them, be suitable in this pandemic. But, even if the filter element is real (I doubt it), it is utterly useless because the air just flows around it instead. It's not fitering any more particles than a surgical mask, which is itself not designed to seal on your face to filter fine particles out of the air.

During the summer of bushfires you may have also had a play with the recirculation setting on your vehicle's ventilation system. I discovered the one on mine actually has an air quality sensor for the auto setting, although I could also see the air getting thicker before it switched itself over to recirculation.

The vehicle also needs an effective seal to stop particles getting in, and clean air the last time the doors were opened. Since that didn't happen I chose to wear my P2 in the car, and I also now keep a couple of genuine P2s handy because, quite frankly, why wouldn't you?

Sam Hollier is an ACM journalist and a motoring fanatic who builds cars in his shed in his spare time.