In August 2006 the TSA set limits for the amount of liquid, aerosol, and gel materials passengers are allowed to bring on an airplane. They created the "3-1-1 for Air Travel" rule: 3.4 oz. (100ml) bottle or less (by volume) ; 1 quart-sized, clear, plastic, zip-top bag; 1 bag per passenger, placed in screening bin. These regulations allow security officers to quickly check and clear liquid items.
There are some exceptions to this rule. Passengers with children may declare reasonable amounts of baby milk, formula, and food; most medication is allowed, as well, with a doctor's note or prescription.
The TSA screens all carry-on baggage, but the weight, dimension, and number of bags allowed is up to the individual airlines. In general, passengers can bring on one small piece of luggage -- it must fit through the TSA x-ray scanner -- and an additional personal item, such as a purse, briefcase, or laptop.
Checked baggage is luggage checked at the ticket counter or curbside and is not accessible to passengers during the flight. Passengers should not carry valuables, important paperwork, or perishables in their checked baggage.
TSA security personnel must be able to access the contents of your checked baggage. If you lock your bag, the lock may be broken during screening and you will not be reimbursed for the damage. In addition, if you wrap gifts, they may be unwrapped during the screening process.
If you are traveling with outdoor gear, guns and camping items, these must be checked. Passengers must follow regulations carefully to avoid having belongings removed from luggage.
Guns must travel, unloaded, in a locked container, and the key provided to security. Ammunition must be securely packed in fiber, wood or metal boxes. (In addition to TSA regulations, additional airlines may have their own rules regarding firearms.)
Other items that must be packed in checked luggage include bows and arrows, animal repellent (less than 2 percent active ingredient) hunting knives, compressed gas cylinders, spear guns, and fishing equipment. Specific regulations may vary by airline.
While many items which cannot be carried on can be safely permitted in checked luggage, the TSA does prohibit some items from even checked baggage. This includes most flammable, explosive, and chemical items.
