Liquids carried into the cabin are limited to 3.4 ounces (100ml) or less by volume and must be stored in clear plastic zip-top bags. Passengers must place these bags in the security bin for checking at security stations. Medicines, baby food and breast milk are exempt from these requirements but must be declared at the checkpoints.
The TSA recommends that batteries and battery-operated equipment be carried into the cabin rather than checked. This allows the flight crew access to the devices in case of a fire. However, recalled or damaged batteries must not be used. Lithium-ion batteries, such as those used in laptops, are allowed on board. However, large pallet shipments of these devices as cargo are no longer allowed because they are extremely flammable.
Locks are allowed on checked baggage but must be accessible by TSA officers. The simplest locks to use are those developed with master key locks, so that officers can use their keys without having to cut the lock. Combination locks can also be used, but only if the combinations are given to the officers.
Firearms, ammunition and firearm parts are allowed only in checked baggage. However, law enforcement officers with the proper clearance may carry guns into the cabin. Guns must be unloaded and stored in a hard-side container with a lock that is accessible by security officers. Ammunition must be packed in containers specially designed for them. Black powder and percussion caps used with these powders are prohibited from check-in and carry-on baggage.
Items that are not allowed in carry-ons and check-ins include explosives, fireworks, flares, aerosols, gasoline, torch lighters, fire extinguishers, bleach and flammable paints. Items allowed in the cargo hold but not in the cabin include tools that are 7 inches or less in length; sharp objects like box cutters and metal scissors under 4 inches; self defense items like throwing stars, nunchucks and brass knuckles; and sporting goods like baseball bats, ski poles and golf clubs. Lighters with fuel are allowed as carry-ons but not as check-ins.
