The short answer:Not by “scanning” the pen to see what’s inside. TSA’s screening tech and procedures areaimed at finding explosives and weapons, not testing cartridges for cannabis. If officers see or suspect an illegal substance (including most THC products), they’ll call local law enforcement, and what happens next depends on federal law and the airport’s/local police’s policy. 

What TSA actually looks for

• Primary mission: aviation security—detecting explosives and other threats. Carry-on CT scanners create 3-D images to help officers spot threat items; they don’t analyze chemical composition to distinguish THC oil from nicotine e-liquid. If a bag needs more screening, officers hand-inspect it.Explosives trace swabs (those quick wipes of your hands or items) aredesigned to detect explosive residue, not narcotics.
  

• If drugs turn up: TSA doesn’tsearch for marijuana; however, if officers discover something that appears illegal, they refer the matter to a law-enforcement officer (LEO).

Bottom line on “can TSA tell?”

Scannerscan show that you have a vape and liquid/cartridges; they cannot by themselves confirm whether a cartridge is THC. Determinations come from labels, packaging, odor, admission, or LEO testing after a referral—not from TSA’s scanning tech. 

Federal rules that matter for THC and CBD

• Marijuana/THCremains illegal under federal law for air travel and on federal property (which includes TSA checkpoints), except for FDA-approved products and hemp-derived items with ≤0.3% THC by dry weight. If suspected, TSA refers to police.
  

• CBD is permittedonly if it’s hemp-derived (≤0.3% THC) or FDA-approved. Anything over that federal threshold is treated as illegal.

What actually happens if TSA suspects a THC vape?

1. Referral to local police. Response varies by airport/jurisdiction.

2. Examples of local policies:
   

• LAX (Los Angeles):Airport Police state they won’t arrest adults possessing amounts legal under California law; however, that doesn’t authorize taking cannabis through TSA or across state lines.
  

• Denver International (DEN): Bans possession of marijuana anywhere on airport property. Travelers can be stopped before or at security. 

Traveling with any vape (nicotine or otherwise)

• Where it goes:Carry-on only. Vapes/e-cigs areprohibited in checked baggage due to battery fire risk. Take steps to prevent accidental activation (e.g., remove battery or use a safety cover). Battery limits apply (≤100 Wh for Li-ion; ≤2 g for Li-metal).
  

• Liquids: Standard 3-1-1 carry-on limits apply to nicotine e-liquid. (Note: THC liquids are still subject to federal law above.)

Never use vapes on the aircraft. FAAprohibits charging/using these devices onboard.

Dogs at the airport: are they sniffing for weed?

TSA’s canine teamsare trained for explosives detection to support aviation security. While detection dogscan be trained on various odors, TSA’s airport canines are deployed to detect explosive odors, not to run drug enforcement for passenger screening. 

Practical takeaways

• If it’s THC, don’t bring it. Federal law governs TSA checkpoints and flights; THC products can trigger a police referral, missed flights, or local penalties—especially at airports that ban possession outright (e.g.,Denver).
  

• If it’s nicotine, pack it right. Keep vapes in carry-on, comply with battery rules, and keep liquids within 3-1-1 limits. Don’t use or charge devices on the plane.
  

• CBD must be hemp-derived (≤0.3% THC) or FDA-approved. Anything elsecan be treated as illegal under federal law. Keep products in original, clearly labeled packaging.
  

• Check the airport’s local policy before you fly; some airports (e.g.,LAX) defer to state possession limits, while others (e.g., DEN) ban marijuana on airport property. 

FAQ

Can I fly between two legal states with a THC vape?

No. Air travel and TSA checkpoints are under federal jurisdiction; marijuana remains illegal federally. 

What if I have a medical marijuana card?

It doesn’t change federal rules at the checkpoint or on the aircraft. TSA will still refer suspected violations to law enforcement. 

Could TSA swab my vape to test for THC?

Those swabs are for explosives trace detection, not for THC/narcotics testing. If a drug test is needed, that would be a law-enforcement matter after referral. 

Will a TSA dog alert my vape?

TSA dogs are trained for explosives, not routine drug detection in passenger screening. Other agencies’ dogs at an airport may have different training, but TSA’s focus is explosives. 

The bottom line

TSA can’t “tell” via scanners that a vape contains THC. But if officers suspect marijuana, they’ll call police, and the situation is then governed by federal law and local airport policy. To avoid trouble, don’t bring THC products to the airport, and if you’re traveling with a nicotine vape, follow the FAA/TSA battery and carry-on rules.