Except for personal medical oxygen cylinders, you can only carry an EMPTY compressed gas cylinder onboard a plane. To be permitted (in either carry-on or checked baggage), it must be clearly visible to the TSA officer that the cylinder is empty.
CO2 Cartridge
Carry On Bags: 
          No
        
  Checked Bags: 
          No
        
   The final decision rests with the TSA officer on whether an item is allowed through the checkpoint.