I hear ya about the suffocating feeling. Drove me nuts during the home renovations, but freeing up my nose would just get me a snoutful of plaster dust. :mad:
The kind of mask that had the two filter things on either side of my face bothered me quite a bit less though because it was a more rigid mask and felt further away from my nose and mouth. IIRC, that one specifically stated it would do diddly to protect you from aerosol or oil based particles, but it definitely helped when we were ripping nasty old stuff out of the ceiling. (No mold, thankfully.) So clearly, as fancy as if seemed, it wouldn’t help against germs of doom.
Your cousin is correct. I’m far from being an expert on this, but generally masks/respiratory protection are rated in different categories and are useful for different tasks.
your standard surgical mask, as mentioned, offers little to no protection from fine particles but rather acts as a physical barrier to large droplets. This is like sneezing into your arm rather than not covering up. Good in some cases, but limited protection from aerosols.
Dust masks/respirators that cover your nose and mouth and are fitted with one or two elastic bands.
This mask will have some level of particulate rating, so that anything larger than a certain size won’t be able to pass through the “fabric”. The most common ones are rated by NIOSH as “N95” and “… has a filter efficiency level of 95% or greater against particulate aerosols free of oil when tested against a 0.3 micron particle” (from here) It seems that N100 are also available, as you found. These will not protect you against exposure to solvents (methanol, acetonitrile, oils, etc) and so are not always appropriate for painting/laboratory protection, but are more than sufficient for health reasons, since bacteria are bigger than the particle size limit, and viruses, while smaller, are usually found in much larger droplets which are usually stopped by the masks.
Full or partial face masks/hoods/PAPRs… I’m not going to go into all of these, but they are more effective forms of protection and for much much smaller particle sizes, but are much more unwieldy, need to be cleaned properly between uses (as opposed to the first two, which are disposable), need to have their protective cartridges changed periodically and even customized for use (you’d use different cartridges for dust than for solvent protection, for example) and in the case of PAPR, need a battery/power source to function.
In the case of a dust mask/respirator and a partial face mask, a proper fit is very important. Companies like 3M and health-and-safety consultants will do mask fittings to make sure you are wearing the correct one for your size/facial structure. Face masks cannot be worn if you have facial hair; you will not get a proper seal through a beard/mustache, and a hood/full PAPR is required instead. Once you know which mask suits you best (3M 8210 for me!), you should wear it with the top elastic on the crown of your head and the lower one at the nape of your neck. It should be a tight fit, and if you cover the mask with your hands and inhale deeply, you should feel the mask “cave in” a little, and if you exhale, it should push out somewhat (negative and positive pressure tests). If your glasses are fogging up, the seal isn’t correct and you aren’t getting the full protection from the mask.