That is a very convoluted way to show that your beard should not cross the seal.
If you want to get the message across, diagrams like this are not very helpful. It leads to people checking for which part of it might apply to them without making them aware of the underlying reason for it.
It's only the best and easiest option as long as what you consider your beard style to be is actually aligning with what that diagram shows. When does a walrus moustache become a horseshoe? When does a villain moustache become a dali? That diagram tries to deliver its message by using ambiguous terms instead of fixating on the actual problem (which is to prevent your beard crossing the seal).
The simpler solution is a seal that works inside the lips. This works much better even for people without beards. It's also smaller and lighter, which matters for all the times the gear must be carried but not actually worn.
Lots of other militaries allow their soldiers to maintain groomed beards. The US is actually kind of an outlier in this regard. But, the military being the military, should they enter a theatre that has a significant likelihood of chemical attack I'm sure those grooming standards would change.
I never heard this before, so I looked into it just now. There appears to be some dispute, since he allegedly had the closely cropped mustache before WW1, which was when he was allegedly ordered to crop it short for gas masks.
Glad I'm not the only one who thought this. I guess it's really not that far from the realm of possibility these days. Why apply machine learning to finding a cure when you can develop a selfie filter that makes for better insta posts during a pandemic?
I have a short full beard but seem to be able to form a seal. If I follow the directions for checking the seal — blocking the intake and breathing in, checking for the mask to collapse in, then blocking the outlet and checking for it to balloon out — it works. So do I have a seal or not?
In case of a coronavirus outbreak I am definitely losing the beard if for some reason I have to leave the house. But I also use a respirator for semi-routine tasks like woodworking to minimize dust exposure.
I have but wanted to make the Chaplin joke anyway. Can't let Hitler get all of the association for that moustache style even if Chaplin did muddy the waters with The Great Dictator.
Every firefighter knows this. Which is why you never see firefighters with beards. (Or sometimes you do but we'll also be shaving on the way to the fire while the truck is bouncing down the road. Some lessons are learned the hard way.)
If you want to get the message across, diagrams like this are not very helpful. It leads to people checking for which part of it might apply to them without making them aware of the underlying reason for it.