Friday, 26 June 2020

Dust Masks and Nail Salons

https://www.osha.gov/SLTC/nailsalons/

So why do Nail Salons use masks, and why do I get cranky when that is used as proof they are safe and effective for Covid-19?


Chemicals Used in Nail Salons
Nail polishes, glues, and other products used in nail salons may contain the following chemicals, among others:
  • Toluene
  • Formaldehyde
  • Dibutyl Phthalate
  • Methacrylate compounds

I grant you they have some use for skin flakes etc, but I never see barbers etc having to wear dust masks.

Are they useful against these chemicals?

I'm going to use acetone as the example as I could actually find the size relatively easily, and the rest are a bitch. A table would be nice. I'm sure I've seen them around.

I miss Sydney Uni library. :P

https://www.researchgate.net/post/How_to_calculate_the_size_of_organic_molecules2


That mask doesn't look sealed around the nose.

Still, this might just be a stock photo.



https://www.bio.umass.edu/microscopy/mol_sieves.htm

Molecular radius, nm

Water 0.193
Acetone0.308





https://www.goodnewsnetwork.org/wp-content/uploads/2015/06/nail-salon-worker-face-mask-CC-rbatina.jpg


https://www.engineeringtoolbox.com/particle-sizes-d_934.html

Particle Size:

Atmospheric Dust  <=40 microns

A micron is a thousand nanometres, thus Dust can be up to 40, 000 nm or

(40, 000/0.308) = ‭129,900 times as big.

Me maths is rusty, so feel free to correct me, but I just think that a dust mask ain't gonna cut it.

So what about a fume hood setup?



A chemical fume hood. It's not perfect, but it is enormously better than a dust mask.
Also, note the eye protection. Acetone and covid19 alike love hitting the squishy eyeballs.

Ok, so it would need to be modified for a nail salon, but why is it we don't see something that hands and feet can enter with a decent suction protecting those outside?


I remember seeing a baby in a stroller parked outside a nail salon at Hornsby. I was worried it had been abandoned or forgotten, so walked towads it. A worker from inside rushed out to pull her baby in.

I realised that they had taken their baby to work, but had decided the air was too dangerous. Of course it is too dangerous. It's too dangerous for the workers but they put up with it because it is a job you can do without English, and I suspect a lot of them are black market too.

OK, so what do the different masks do?

https://www.envirosafetyproducts.com/resources/dust-masks-whats-the-difference.html


Respirator Rating Number Class

  • 95 - Removes 95% of all particles that are at least 0.3 microns in diameter
  • 99 - Removes 99% of particles that are at least 0.3 microns in diameter
  • 100 - Removes 99.97% of all particles that are 0.3 microns in diameter or larger. HE or HEPA quality filter.

N95 is better than a typical surgical mask and is the best possible for all but a few people, and is quite expensive in any case. It is typically NOT REUSABLE.

And it is useless for acetone. It does diddly. Even if you squidge about and have actone in globules, bonded to water, an awful lot of it will got right through a 300 nm hole.

Again, feel free to prove me wrong, I don't mind and would appreciate some paper that disputes my understanding. But as far as I can see, the masks in nail salons are theatre - designed to reassure people without helping anyone, and possibly causing health hazards by themselves.

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