7.2 Flammables, Fuel, and Compressed Gas

7.2 Flammables, Fuel, and Compressed Gas

Quick answer: Butane, propane, gasoline, lighter fluid, chlorine for pools and spas, cooking spray, and torch lighters are No carry-on / No checked. A CO2 cartridge defaults to No / No. Except for personal medical oxygen, you may carry only an EMPTY compressed-gas cylinder, and it must be clearly visible to the TSA officer that the cylinder is empty. Engines are No in carry-on; checked only if completely purged of fuel, residue, and vapors, and the airline may still refuse. Cigarettes and cigars are Yes / Yes. TSA cites FAA PackSafe for hazmat. The final decision rests with the TSA officer.

This section trains the public fuel and compressed-gas map for the TAB and the checkpoint. It does not teach how to conceal fuel, vent a tank in secret, or defeat screening. SSI stays unpublished. You are learning live What Can I Bring results, the empty-cylinder visibility rule, and the difference between a never-fly fuel and a checked-only purged engine.

Fuel and oxidizer never-fly items

TSA's Flammables category and the complete list treat bulk fuels and several related chemicals as No / No:

• Butane — No / No (TSA points regulatory questions to FAA PackSafe lighters)
• Propane — No / No
• Gasoline — No / No
• Lighter fluid — No / No
• Chlorine for pools and spas — No / No (TSA points to PackSafe "other")
• Cooking spray — No / No (TSA points to PackSafe aerosols)
• Torch lighters — No / No (needle-like flame hotter and more intense than a common lighter)
• Gun lighters — No / No

TSA civil enforcement lists any flammable liquid or gel fuels, including but not limited to gasoline, lighter fluids, cooking fuels; turpentine and paint thinners, at $450–$2,570 when discovered at the checkpoint, sterile area, or onboard and when discovered in checked baggage. There is no "I will check it" rescue for gasoline. A residual splash in a spare can is still gasoline.

Chlorine for pools and spas is not a camp-stove story and not a pool-party exception. It is No / No. Do not analogize it to toiletries. Toiletries have limited PackSafe exceptions; pool chlorine does not on the live TSA page.

Cigarettes are not butane

Cigarettes are Yes / Yes. Cigars are Yes / Yes. Tobacco in those forms is a generally permitted item on the Flammables category page. That pairing is a classic TAB trap. A carton of cigarettes is not a fuel canister. A butane refill, a propane cylinder, or lighter fluid is not "the same as smoking supplies." Screen the object: paper tobacco versus a pressurized or liquid fuel.

Related ignition items split by construction, which is why you read the item page:

• Disposable and Zippo lighters — Yes / Yes (special instructions). Unfueled disposable and Zippo lighters may go in checked bags. Fueled lighters are prohibited in checked bags unless they meet the Department of Transportation exemption allowing up to two fueled lighters if properly enclosed in a DOT-approved case. TSA points questions to PackSafe lighters.
• Safety (non-strike-anywhere) matches — Yes carry-on for one book; all matches are prohibited in checked baggage.
• Strike-anywhere matches — No / No.
• Lithium-battery-powered lighters — Yes carry-on / No checked on the live listing.
• Torch lighters and gun lighters remain No / No.

Cordless butane curling irons are a narrow device exception, not a butane-refill exception: Yes (special instructions) carry-on / No checked. A safety cover must be securely fitted over the heating element, and the device must be protected from accidental activation. Gas refills (spare cartridges) are not allowed in either bag. The iron is not permission to pack a spare butane can.

Compressed gas: empty and visible, or it does not fly

TSA's CO2 Cartridge page is No / No as the default. The special instruction is the rule you must memorize:

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.

Read that as three tests, not one slogan:

1. Filled cartridges — not permitted (the live columns are No / No).
2. Empty cylinders — only if emptiness is clearly visible to the officer, in carry-on or checked.
3. Personal medical oxygen — published exception to the empty-only default, with more rules on the medical-oxygen and small-cartridge pages.

TSA's small compressed gas cartridges listing adds public mechanics: unless the cylinder is personal medical oxygen, the regulator valve must be completely disconnected so the cylinder has an open end the officer can inspect. TSA officers will not remove the seal or regulator valve. If the cylinder remains sealed and is not required for personal medical oxygen, it does not get a homemade "I will open it later" exception at the belt.

Life vest is a different published exception: a life vest with up to two CO2 cartridges inside, plus two spare cartridges, may go in carry-on or checked bags. You may not transport CO2 cartridges without the associated lifejacket. Two spare cartridges in a toiletry bag with no vest are not a life-vest exception.

Recreational oxygen — non-medically required, flavored, or canned oxygen — is No / No. Do not treat a wellness canister as medical oxygen. Medically necessary personal oxygen may go through the checkpoint and into the gate area under special instructions, but FAA treats those cylinders as hazmat in the aircraft cabin; the traveler must arrange oxygen with the airline. Portable oxygen concentrators follow a separate FAA-accepted-device path.

Engines: carry-on No; checked only if completely purged

TSA's live Engines and Engine-powered Equipment Completely Purged of Fuel page is the checked-only candidate in this chapter:

• Carry-on bags: No
• Checked bags: Check with airline
• Engines must be completely purged of all liquid or gaseous fuel, including residue and vapors, to be allowed in checked baggage.
• Even if completely purged, some airlines may refuse engine-powered equipment in baggage if it has ever contained fuel.
• Check with the airline before travel.

Engine-powered equipment with residual fuel (chainsaws, generators, trimmers, and similar) is No / No. No amount of fuel may remain, including residual vapors. A "little left in the tank" is residual fuel. That is never-fly, not checked-with-a-warning.

Camp stoves are a related special-instructions pair: Yes / Yes only if they are empty of all fuel and cleaned so that no fuel vapors or residue remain. Wrap cords and layer items so officers can get a clear view. A stove with fuel still in it is not that listing.

Car parts without fuel or traces of fuel may travel; engine parts in checked bags should be in the original box and free of gasoline and oil. Traces of fuel put the part back in the residual-fuel problem.

PackSafe overlay and a flammables table

PackSafe repeats that most dangerous goods are forbidden in passenger baggage and that TSA prohibited-item rules are separate. Flammable liquids, gases, and oxidizers are named hazmat classes. A TSO does not have to recite the full PackSafe chart on the TAB, but you must recognize that a What Can I Bring No / No fuel is both a security prohibited item and a dangerous good.

Typical non-lithium dry batteries (AA, AAA, C, D, and similar) are Yes / Yes if protected from damage, sparks, or a dangerous evolution of heat. They are not a fuel exception; they are a battery listing. Lithium spare cells belong to a later chapter.

Realistic scenario

A traveler brings a small propane camping cylinder, a CO2 cartridge for a bike pump, a carton of cigarettes, and a chainsaw "drained last weekend." Cigarettes are Yes / Yes. Propane is No / No. The bike-pump CO2 cartridge is a CO2 cartridge: default No / No unless it is empty and visibly empty. A chainsaw with residual fuel is engine-powered equipment with residual fuel: No / No. Even a fully purged engine is No in carry-on and only check with the airline as checked baggage — and the airline may still refuse because it once held fuel. The officer does not trade the cigarettes for the propane. The final decision rests with the TSA officer.

Bookmark the Flammables category, the CO2 Cartridge page, Engines completely purged, Civil Enforcement, and FAA PackSafe.