Some of the Transportation Security Administration's liquid regulations as of 2015 include the 3-1-1 rule, which means a passenger carries one quart-size bag filled with liquids that weigh no more than 3.4 ounces each, with a limit of one bag per traveler. Liquids include pastes, creams, aerosols and gels.
The TSA allows some liquids that exceed the 3.4-ounce rule such as baby formula, breast milk and medications. The passenger needs to notify the TSA at the checkpoint. International travelers can carry purchased duty-free items in excess of 100 milliliters in clear containers and undamaged tamper-evident bags, for connecting flights inside the United States.