No—filled CO₂ cartridges are banned from checked bags; only empty cylinders or those installed in an approved life vest may fly.
Why CO₂ Cartridges Raise Red Flags
Those palm‑sized metal tubes pack up to 900 psi of pressure. Change cabin temperature or puncture one mid‑flight and the cartridge can rupture or rocket around the hold. For that reason the TSA bans charged CO₂ cylinders from both cabin and hold. Agents will only clear a cylinder after they verify it is vented and visibly empty.
The same stance shows up in the FAA PackSafe database. Aviation safety staff label full cartridges “hazard class 2.2,” right next to oxygen bottles. They point out that metal shards from a burst cylinder can pierce luggage walls, hydraulic lines, or insulation around wiring. One tiny device, many ugly scenarios.
Travelers who forget even a single CO₂ cylinder learn quickly. A Houston cyclist lost his TSA PreCheck status for twelve months after agents pulled a 16‑gram bike inflator from his bag. He appealed and later regained access, but the delay, paperwork, and a public warning on the TSA blog show how tightly the rule is enforced.
| Item | Carry‑On | Checked |
|---|---|---|
| Full spare cartridge | No | No |
| Empty cylinder (open valve) | Yes | Yes |
| Life vest with 2 cartridges + 2 spares | Yes* | Yes* |
*Allowed only when the cartridges are secured to an approved inflatable life jacket or similar safety device. Loose spares must travel beside the device, not scattered through the bag.
The Two Exceptions That Work
Inflatable Life Jackets
The most common carve‑out involves personal flotation devices. International shippers list the cartridges as “dangerous goods UN 2990,” yet they waive small quantities attached to a vest. U.S. carriers follow that model. You may pack one vest per flyer with up to two cartridges screwed into the inflater and two sealed spares taped to the jacket. Leave the pull‑cord safety clip in place or twist off the firing pin so turbulence cannot trigger inflation.
Location matters. American Airlines only accepts the vest in checked baggage, while Delta and United allow it in either bag. All three cap you at four charged cylinders per passenger, matching federal limits.
Prosthetic or Medical Devices
Powered knee joints, exoskeletons, and mobility cushions sometimes rely on tiny CO₂ charges. Because mobility ranks as a civil right, security teams permit as many cylinders as the device needs. Bring a note describing the equipment, and tell the screener before your bag hits the belt. Quick disclosure beats awkward surprises every time.
Avalanche Airbags and Bike Vests
Self‑inflating avalanche packs and motorcycle safety vests use larger cylinders. International rules let each flyer travel with one such device plus one spare, yet U.S. screeners usually insist the cylinder be empty. Vent it, remove the head, drop both parts in a zip bag, and refill at a ski or dive shop after landing. If you need the pack charged on arrival, ship the cartridge by ground courier instead of checking it.
Airline Policy Snapshot
Below is a quick glance at carrier rules. Always request confirmation before flying; agents have the final word.
| Airline | Life Vest | Loose Cartridges |
|---|---|---|
| American | Checked only | No |
| Delta | Cabin or checked | No |
| United | Cabin or checked | No |
| British Airways | Auto approval × 2 | No |
| Southwest | Case‑by‑case; call first | No |
Smart Packing Tips
- Buy local: Sporting shops worldwide stock 16‑gram cartridges.
- Carry a mini pump: A 90‑gram hand pump fills two bike tires and flies through screening without a shrug.
- Vent, label, show: If a cylinder is empty, mark it with tape reading “EMPTY” and unscrew the nozzle. Screeners appreciate the courtesy.
- Print the proof: Tape your airline’s email approval next to the cartridges. No phone signal needed at the counter.
- Mind connections: Crossing borders means new screeners. A cartridge cleared in Tokyo can still be seized in Dallas. Plan layovers wisely.
- Ship smart: Ground couriers treat CO₂ as “limited quantity.” Declare it; shipping is cheap, and your gear arrives stress‑free.
Cartridge Sizes and Limits
Most riders and gamers rely on 12‑gram or 16‑gram steel capsules. Sailors and anglers often carry 25‑gram cylinders for life jackets, while avalanche airbags demand 30 to 60 grams. Quantity rules do not change with size; one vest still equals two live cartridges plus two spares. Yet weight matters at altitude because heat expands the gas. That is why the International Air Transport Association, or IATA, sets a 50‑millilitre (about 28‑gram) volume ceiling per cartridge carried by passengers, so anything larger must travel empty.
After‑Landing Resupply Guide
Once on the ground, reload options abound:
- Bike shops: Every city bike shop sells 16‑gram cartridges.
- Dive centers: Coastal towns stock threaded 25‑gram cylinders for BC inflators and speargun power packs.
- Outdoor stores: Outfitters like REI or Decathlon carry multipacks up to 88‑gram for soda machines and pellet rifles.
- Marine chandlers: Need a high‑capacity yellow 33‑gram jacket cylinder? Boat‑supply stores at marinas usually have a shelf full.
Keep the receipts. Some countries inspect outgoing luggage for proof that cartridges were purchased locally and are therefore legal to export.
International Stopover Caveats
A nonstop flight is simplest, yet vacations rarely follow a straight line. Suppose you depart Los Angeles for Whistler with a short change in Vancouver. Canadian security allows a life‑jacket cylinder, but U.S. agents at the return border pre‑clearance might reject a spare that passed northbound. Similar mismatches pop up in Singapore, Dubai, and São Paulo. Print the local authority’s rule—usually hidden on an airport police web page—and keep it with your boarding passes. If policies clash, surrendering a three‑dollar cylinder hurts less than missing a flight, and replacement cartridges are easy to buy once your adventure starts.
Quick Decision Tree
- If the cartridge is sealed and not attached to life‑saving gear, leave it home.
- If it is installed in a personal flotation device and you have two or fewer spares, pack it after notifying the airline.
- If it powers a medical aid, carry documentation and tell the screener.
- If the cylinder is empty, keep the valve off and place it in view for inspection.
- If none of the above fit, buy cartridges after touchdown or ship them separately.
Bottom Line
These guidelines boil down to two clear paths: fly with an empty shell or fly with a life vest and only four cartridges. Stick to that formula, ignore the impulse to stash extras, and both you and the airline crew will breathe easier on takeoff.
Follow these proven tactics and your cartridges will never derail a holiday, a race, or a powder day; the skies stay friendly, and your gear stays legal.