PackSafe - Small Compressed Gas Cylinders

Small Compressed Gas Cylinders and Cartridges in or with a Device

Carbon dioxide (CO2) and other nonflammable, nontoxic gases

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.

For air guns and similar devices, see TSA's security rules.

*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.

Regulation that allows it: 49 CFR 175.10(a)(25)

Small Compressed Gas Cylinders for Mechanical Limbs

Quantity limits: A sufficient number of cylinders/cartridges to ensure an adequate supply for the duration of the journey.

Cylinders/cartridges containing nonflammable, nontoxic gases may be worn in mechanical limbs and spare cylinders/cartridges may be carried in carry-on or checked baggage.

See the regulation: 49 CFR 175.10(a)(12)