chillinn, do you have documentation/published-research on your information?
Mechanical filter, this explains nicely about how a HEPA filter, rated to 3nm, will filter nearly all airborne particles, 99.97% of particles down to 3nm, and even a larger percentage of those far smaller than 3nm. (idk where the mu is on my iPad, so I have been using nm to mean "micrometers," sorry for any confusion with nanometers)
Wikipedia said:
HEPA filter are all filters meeting certain efficiency standards. A HEPA filter must remove at least 99.97% (US) or 99.95% (EU) of all airborne particulates with aerodynamic diameter of 0.3 μm. Particles both smaller and larger are easier to catch, and thus removed with a higher efficiency.
Wikipedia said:
The SARS-CoV-2 virus is a large pleomorphic spherical particle with bulbous surface projections. The average diameter of the virus particles is around 0.12 μm. The diameter of the envelope is 0.08 μm and the spikes are 0.02 μm long.
Micrometers (μm) are one millionth of a meter (m), or one thousandth of a millimeter (mm). To give you an idea of how small micrometers are...
Between 1 μm and 10 μm:
1–10 μm – length of a typical bacterium
10 μm – Size of fungal hyphae
5 μm – length of a typical human spermatozoon's head
3–8 μm – width of strand of spider web silk
about 10 μm – size of a fog, mist, or cloud water droplet
Between 10 μm and 100 μm:
about 10–12 μm – thickness of plastic wrap (cling wrap)
10 to 55 μm – diameter of wool fibre (not a thread, which is made of many fibres)
17 to 181 μm – diameter of human hair
70 to 180 μm – thickness of paper
Regarding 3M filters:
"certain organic vapors"
3M model (6001, 6003, 6004, 6005, 6006, 6009, 60921, 60923, 60926, 60925, 60928) filters are rated for "certain organic vapors," and include charcoal filtering; when they are paired with the P100 or P95 prefilter and prefilter retainer as a combination filter/cartridge, offer organic filtering superior to filters listed below only rated for
"nuisance level organic vapor relief,"
P100, round or disk shaped, pink, magenta or grey, 3M model (2091-07000, 2097 or 07184, 2291, 2297, 7093C or 37173) filters are rated for "nuisance level organic vapor relief, " and nuisance levels refer to concentrations below the OSHA PEL or other government standard, whichever is lower.
But with either set up (including 3M P95 filters), all virus is an easy target for them, according to the 3M filter expert I spoke with. I had to wait on hold nearly 2 hours, but he set my mind at ease.
(Apparently, the reason 3M personal protective equipment (PPE) is difficult to get a hold of now when once (like in early February 2020) so ubiquitous, my understanding at least, is the federal government bought up all stock everywhere and are hoarding it. By now, the feds have enough respirators to equip every man, woman and child physically within the borders of the US a few times over. I don't know how true that is, sounds a bit like a whacky conspiracy.)
The N95 medical masks are a different animal. They must be fit tested to seal against the face. A 3M (6000, 7000, 8000, & 9000 series) or Honeywell (with their own filters I am not familiar with) reusable respirator seals air tight against the face, and matched with proper organic filters, will certainly be protective (but won't protect others around you from you).
Regarding
naked individual virus being able to go through even a layered cloth mask like it isn't there... this is my own conjecture, based on my powers of deduction. The finest, tightest weave made of spider silk would not be able to prevent virus from going through it, because a virus is about 100x smaller than any weave possibly could be.
A
plain weave (the tightest and simplest of all weaves) of 0.3mm diameter Kevlar fibers wrapped to about 10 times that size, or 3mm, is about as tight a weave as practical. Coronavirus is 2500 times smaller than the diameter of Kevlar fiber, and at least 250 times smaller than the smallest gaps between its plain weave threads.
Internet search the news regarding newest studies about the cloth masks (here's what's at
CDC),
because these ordinary cloth masks, even cheesy ones, regardless of the obvious, help immensely to prevent infection for the wearer, because while the point of them is to stop your droplets, which may be filled with virus and large enough to be trapped in a cloth weave, they do end up also stopping the droplets coming at you. Coronavirus is not airborne, and it can only hang for a short time in the air in these far larger droplets that are sneezed and coughed out.
Protecting the eyes is just as important in public as protecting the nose and mouth, prescription glasses and sunglasses will do, as well as safety glasses.
Contact wearers should have stopped wearing their contacts, at all, months ago. Don't wear contacts until the pandemic has abated.
The main infection vector is your own fingers,
IMO. Keep those clean, and don't touch your face, keep back from others, and you won't be infected, mask or not.
Note: CDC disagrees with me (and I am terrible at biology, but I can read and generally my logic is bulletproof)
COVID-19 is primarily transmitted from person-to-person through respiratory droplets. These droplets are released when someone with COVID-19 sneezes, coughs, or talks. Infectious droplets can land in the mouths or noses of people who are nearby or possibly be inhaled into the lungs.
CDC says being sneezed and coughed on is the main infection vector. I just don't buy it. Yes, that will infect you. How often are the sick coughing and sneezing on the uninfected? I think, I really believe, the only way this could spread so fast is we do it to ourselves: someone sneezes, the infected water droplets hang briefly, maybe as long as 15 minutes to an hour depending on environmental circulation systems, but ultimately they land on surfaces, and Coronavirus can exist there for days, depending on what that surface is (not on copper or silver, or any other oligodynamic metal, like brass), we come along later, lean against this surface, touch it, then rub our eyes. I think it takes 2 instances of a single virus to be infected, and that can happen with a single nose rub. Don't touch your face.
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