In 2026, most international airports still adhere to the 3-1-1 rule, meaning liquids are not "prohibited" but are strictly limited in volume. Prohibited items include any liquid or gel in a container larger than 3.4 ounces (100ml), even if the bottle is only partially full. This includes common items like water, soda, toothpaste, hair gel, and perfumes. Additionally, highly flammable liquids (like lighter fluid or spray paint), toxic chemicals (like bleach or acid), and certain "spreadable" foods (like large jars of peanut butter, jam, or soft cheese) are banned entirely from hand carry due to security and safety risks. There are two major exceptions: Medication and baby food/formula are permitted in larger quantities, though you must declare them to the TSA or security officer for separate inspection. A peer-to-peer tip for 2026: many airports are now installing advanced CT scanners that may eventually allow for larger liquids, but until these are universal, sticking to the 100ml rule is the only way to ensure your expensive toiletries aren't confiscated at the checkpoint.