Under the current TSA 3-1-1 rule for 2026, any individual liquid, gel, or aerosol container exceeding 3.4 ounces (100 milliliters) is not allowed in carry-on luggage. All compliant containers must fit inside a single, clear, quart-sized zip-top bag. Common items that are frequently confiscated include full-sized water bottles, large shampoo bottles, and spreadable foods like peanut butter or yogurt. There are, however, critical exceptions: medically necessary liquids (like insulin or IV bags), baby formula, and breast milk are allowed in larger quantities but must be declared for separate inspection. Additionally, if you have passed through security and purchase a large drink at a terminal shop, you are permitted to bring it on the plane. If you must transport larger volumes of liquids, they should be packed securely in your checked baggage.