I don’t think that policy is unreasonable for a plane ride. Just because someone wears a P100 mask doesn’t mean that their mask filters outgoing air as that’s not the design goals for most of the use cases of P100 masks.
Checking on a case-by-case basis whether a particular P100 mask is not designed like an average P100 mask is likely not feasible in that context.
I don’t think that policy is unreasonable for a plane ride. Just because someone wears a P100 mask doesn’t mean that their mask filters outgoing air as that’s not the design goals for most of the use cases of P100 masks.
Checking on a case-by-case basis whether a particular P100 mask is not designed like an average P100 mask is likely not feasible in that context.