Originally Posted by
JohnBurke
You're aware that beards are not ferrous, correct? Is your beard made of steel wool?
Oxygen concentration can enhance combustion. Hair burns, and applying oxygen to a flammable item while burning is taking place will accelerate the combustion process.
Unless you're stupid enough to smoke inside an oxygen mask, this generally isn't a problem. Simply applying oxygen to a beard will not cause it to burn. How many circumstances can you think of in which an ignition source is applied to a beard in a cockpit while wearing an oxygen mask?
Are you aware of an ignition source inside an oxygen mask?
What does ferrous have to do with it? Ferrous metals don't necessarily burn particularly well...unless they are fuzzy (or powdery). I-beams and iron pots don't normally catch fire. The steel wool example is relevant because the highly concentrated oxidizer is readily available to a large surface area in small volume...kind of like a beard.
If part of the beard sticks out of the mask, O2 could flow out saturating the beard immediately outside the mask. A firefighter exposed to a sparks/flame could experience rapid combustion of the beard, which would be incapacitating (O2 mask destroyed, face melted). Also weapons and munitions can make sparks...
This came up with certain military dudes (the kind partial to epic beards) using 100% O2 in certain situations.