They have a rule about using them on the plane, not actually carrying them onto a plane.
I guess it's a matter of your mix. I don't mix my own and never get more than 50% PG. Usually more on the VG side. I get my stuff made in America from http://www.mtbakervapor.com/ . I can be sure there are no extra chemicals in it this way. Most stuff out of China can't be trusted...
Just broke my personal record for number of consecutive days without dying!