Originally Posted by
Rubato
Up to 2 (?) CO2 cartridges can be carried aboard according to the TSA website. I don't have the TSA printout handy but I have carried them (and a copy of the handout for local inspection) with inflatable personal flotation devices.
They took my single one in one on my way back, but the first airport had no problem. Same with my lock-pick kit. So your results may vary. Depends on how much you want to fight it.