Earlier quoted context omitted.
Thanks! Usually yes - sometimes the gate attendant doesn't understand that the exhale is filtered (I assume this was the problem with your respirator). We have guidance on that here: https://narwallmask.com/pages/usage-guide#h:flying
Yeah, I actually had an attachment to filter the exhale valve. I decided to just swap out as soon as they asked rather than explain (because I had a 3M 1860 N95 in my pocket) which seems to have been the right choice since one of them started to get belligerent about the respirator very quickly as I started taking it off. It looks like they're very sensitive to people doing non-standard things. I'm not even one to ar…
1) so scared of their management that they won't listen to people explaining the masks are filtered or
2) simply unable to understand that a non-standard mask could have a filtered exhale valve (which is much safer than a cloth mask for others, too).
I had the exact same thing happen to me on 4 different flights, with the flight attendants becoming very aggressive. I brought a short note with a diagram of how the filtration works, and pointed it out to them, and they just told me "sorry, Mayo Clinic guidelines say you can't wear that." This was on United, American Airlines, and Delta.
The tip I figured out on my last flight was to wear a hoodie that covered up the respirator on the side, and then wear two surgical masks over the respirator in front. Haven't gotten a second look since then. I don't think this would be possible with the narwhal mask (unfortunately).