Containing small nonflammable gas cylinder cartridges

Quantity limit: Up to four cartridges/cylinders containing nonflammable gas may be carried. Each cylinder must not exceed 50 ml (equivalent to 28 g carbon dioxide cartridge).

May be carried in checked baggage only.* Airline approval is required.

Cartridges/cylinders not installed in the device should be securely packed.

Compressed gas cylinders, canisters, and cartridges with a volume larger than 50 ml are forbidden in baggage unless covered by another exception in this table.

Though allowed in carry-on baggage and checked baggage under U.S. and international hazardous materials regulations, TSA security rules allow these cartridges in checked baggage only.