Yes! I like that "Petri dish" analogy. It is so correct. Even OSHA in their long-held guidelines (until 'COVID") stated that N95 masks (respirators) were to be used as a last resort in environments of high airborne particulates and not to be used for more than 20 minutes, to which they were considered as useless. N95 respirators were originally designed by 3M Corporation for use in the coal industry. They were never designed for the prevention of germs. A variation of the N95 is the surgical mask, which really has the same functionality as a N95 with perhaps some aesthetic variations. It is designed so the surgeon doesn't drool, cough, or sneeze into open wounds. It has more to do with sputum than air born germs.

Yes! I like that "Petri dish" analogy. It is so correct. Even OSHA in their long-held guidelines (until 'COVID") stated that N95 masks (respirators) were to be used as a last resort and not for over 20 minutes. N95 respirators were originally designed by 3M corporation for use in the coal industry. They were never designed for the prevention of germs. A variation of the N95 is a surgical mask, which is really the same functionality as a N95 with perhaps some aesthetic variations. It is designed so the surgeon doesn't drewel of sneeze into open wounds. It has more to do with sputum than air born germs.