"The amnesty boxes are owned by the Department of Aviation here in Chicago and serviced by us at the police department," says Maggie Huynh, public relations coordinator at the Chicago Police Department. "The boxes are where travellers can safely dispose of cannabis and cannabis products before travel."
The placement may seem counterintuitive to those who want to avoid running into legal trouble, so we spoke with experts to find out exactly what you need to know about flying domestically with pot.
So, to be clear, can I fly with pot?
No. Here's why. According to Larry Mishkin, a Northbrook, Illinois, lawyer at the Hoban Law Group, which provides legal services for the clients in the marijuana industry in the United States and internationally, carrying pot onto a plane is a federal crime.
"Marijuana is illegal under federal law, and federal law governs airplane travel in this country," he says.
The airspace you'll be travelling through is considered federal territory; hence, why it can't come on your flight. That includes flying within states where pot use is legal, or flying between states - even if both allow it for recreation.
If you leave a state with marijuana, "you've broken the law of the state that you purchased it in, you've broken the law of the state that you're going into, and you've broken federal law," Mishkin says.
Mishkin advises people not to try to fly carrying pot. It's illegal. "Know the law, respect the law and stay off radar screens," he says.
What should I do if I get to the airport and still have pot?
That depends on a few factors, like where you're flying out of and how much pot you have in your possession, says Mishkin.
Despite pot being illegal on the federal level, "certain airports, like LAX and O'Hare, have publicly announced that they will not stop any outbound passenger in possession of an ounce (28g) or less of marijuana," says Mishkin. "If, however, you arrive at the airport and realise you have marijuana in your possession and do not want to travel with it, you can deposit it in the amnesty boxes if there are any present, or you can throw it in the trash."
Todd Maybrown, a partner at Allen, Hansen, Maybrown and Offenbecher in Seattle, has similar suggestions for passengers who show up to the airport with pot in tow.
"In a perfect world, I would recommend that people return to their vehicle and place any marijuana in a secure compartment, such as the trunk or a locked glove box," says Maybrown. "In an imperfect world where the passenger does not have a vehicle at the airport, a trip to the bathroom may be the best solution. There are no cameras in the bathroom and toilet bowls can be flushed."
Where is marijuana legal?
You can check where marijuana is legal on websites such as the National Conference of State Legislatures and Leafly. The laws governing it in the United States are ever-changing, and confusing to follow. What applies one day might not the next.
"We try to give people advice, and then sometimes the laws change on us literally overnight," says Mishkin. "This is not an industry to take chances."
States have different rules around usage. In California, for example, a person 21 and older can carry up to an ounce of marijuana, or eight grams of it (a third of the weight). In Illinois, your limit is also about an ounce, but with a smaller amount of concentrated marijuana - a maximum of five grams - and no more than 500 mg of THC in the form of edibles. Users need to familiarise themselves with the existing laws in the places they intend on consuming marijuana.
What happens if TSA finds marijuana in someone's luggage?
TSA's primary concern is passenger safety and detecting potential threats to aviation. In fact, the TSA website states: TSA security officers do not search for marijuana or other illegal drugs.
"The TSA has gone out of its way to say that its focus is not on marijuana," Mishkin says.
Because the TSA is a federal agency, its officers must enforce federal laws.
"If a TSA officer comes across (pot) while they're conducting a bag check, they are obligated to report it to the police, and then it's up to the police how they want to handle it," says TSA spokesperson Lisa Farbstein.
With states passing new legislation on the topic or changing existing laws, a pot-carrier's fate is hard to predict.
"You really run the risk of becoming a guinea pig if you decide to go on a plane with marijuana, even if it's legal in the place where you started, or in a place where you get to finish the trip," says Maybrown. "There's so much confusion and uncertainty about what new rules could or would apply."
Lawyers say it is unclear what exactly TSA would do if you had weed in your bag. If you're caught with pot at an airport in Chicago, or another place in America where pot use is allowed, you may be waived on or simply asked to get rid of it before you board. "It's up to the officers to make those sorts of decisions," Farbstein said.
"TSA will encourage (amnesty boxes) to travellers if they have cannabis on them," adds Huynh, of the Chicago Police Department. "They don't call us unless it appears to be clearly illegal amounts, like a suitcase full."
What if I have a medical marijuana ID card?
Mishkin says that there's a distinction for medical use of marijuana in the eyes of the law.
"People who have their state medical card that shows they are patients are typically treated a little more leniently than somebody else," he says.
But having a medical marijuana card may only help you sometimes. At the airport, TSA doesn't have the jurisdiction or ability to check the validity of those cards. The agent could still pass you off to the local police, who will assess the situation. The state you're in is also important. If there's no medical-marijuana program there, a card will mean "absolutely nothing," Mishkin says.
Can I fly with CBD?
As long as your CBD product contains no more than 0.3 percent THC, or is approved by FDA, you can bring it on a flight. If the product is a liquid or food, it must comply with the usual TSA carry-on policy.