TSA officers enforce federal limits on liquids and restricted devices at U.S. checkpoints, shaping what passengers can carry and why items are seized. The 3-1-1 rule and the 3.4-ounce limit govern carry-on liquids and gels, while TSA rules and FAA lithium battery restrictions bar spare lithium batteries from checked luggage. Vapes, e‑cigarettes, and power banks must travel in carry-ons under FAA guidance. Under post‑9/11 mandates, officers can seize prohibited items at checkpoints, without appeals at the gate. Everyday items such as peanut butter, hummus, and toothpaste face confiscation if containers exceed 3.4 ounces. Airlines follow FAA policies reinforced in 2025, as CT scanners expand and enforcement varies by airport.
