The TSA's liquid limit for carry-ons—known as the 3-1-1 rule—allows travelers to pack liquids, aerosols, gels, creams, and pastes under 3.4 ounces (100 milliliters) in their carry-on bags. Passengers are allowed up to one quart-sized bag per person, or roughly nine 3.4-ounce containers in a single quart-sized bag.