TSA institutes what it calls a three, one, one (3-1-1) carry-on restriction regarding liquids. This means that each passenger may bring one quart-sized clear plastic zip-top bag containing liquids in containers no larger than 3.4 ounces (100ml) each. You must separate or remove this bag from your carry-on bag to be inspected and x-rayed separately. Items such as baby food, formula, medications and breast milk are allowed to be in containers exceeding 3.4 ounces as long as they are declared for inspection at the checkpoint.
There are various items that are prohibited from being carried on any aircraft. While some of these items may be permitted in your checked in baggage, others are entirely banned from being brought onto a flight. Sharp items including box cutters, knives and swords may not be included in carry-on luggage. Some sporting goods, including baseball bats, hockey sticks and spear guns, may be checked in, but are not allowed to be carried on a flight. Similarly, guns and firearms, including ammunition, flare guns and pellet guns, need to be checked in. Some items that are entirely prohibited from flights include explosive and flammable materials, including dynamite, hand grenades and lighter fluid.
Travelers with disabilities and medical conditions may bypass some of these rules with certain exceptions. For example, liquid medications exceeding the size requirements for carry-on liquid items may be brought on the aircraft as long as they are declared to a Transportation Security Officer. This includes both prescription and over-the-counter medications required for medical conditions or disabilities. All aids or devices required for individuals with a disability, including wheelchairs, crutches, supplemental oxygen tanks and service animals are allowed on the flight.
