Under the standard 3-1-1 liquids rule, you can carry liquids, gels, and aerosols in containers of 3.4 ounces (100ml) or less. All these containers must fit comfortably into a single one-quart, clear, plastic, zip-top bag. Common items include shampoo, toothpaste, and perfume. In 2026, exceptions remain for medically necessary liquids, baby formula, and breast milk, which can exceed the 3.4-ounce limit but must be declared for separate screening. Drinks purchased after passing through the security checkpoint are also allowed on the plane. If you have TSA PreCheck, you usually do not need to remove this bag from your luggage, but standard passengers should keep it easily accessible to place in a bin for X-ray inspection.