Chemicals in spray, liquid or gel form that may be used to disable people or conceal explosives, biological weapons or poison are not allowed in carry-ons or checked in luggage. This list includes chlorine, liquid bleach, filled cigarette lighters, fire extinguishers, tear gas, spray paint and any kind of flammable liquid or gel. Realistic replicas of incendiaries are also disallowed.
Less lethal liquids, like shampoo and toothpaste in full-sized packages can be packed in luggage and checked. Snow globes and other decorative items with liquid inside and gel shoe inserts must also be checked.
Explosive and incendiary materials, like blasting caps, dynamite, fireworks, flares, grenades, gun powder and plastic explosives are not allowed under any circumstances.
While registered firearms can be checked if they are unloaded, locked in a hard-sided container and declared, some airlines have internal policies that prohibit guns on board. Pellet guns, starter pistols and ammunition can also be checked if airline policy agrees.
Martial arts and self-defense weapons such as throwing stars, brass knuckles, billy clubs and nunchucks can be checked but are not allowed in carry-on baggage. Tools under 7 inches can be carried on if sheathed or securely wrapped. Tools over 7 inches, including cordless power tools, can be checked with baggage and should also be sheathed or wrapped to avoid injury to inspectors and baggage handlers.
Sharp objects like knives, razors, razor blades, swords, axes and scissors can be sheathed or wrapped and packed in luggage. Scissors under 4 inches in length, like cuticle scissors, are allowed in carry-on bags, but even small sharp objects should be wrapped to prevent injury.
Sporting equipment, for example bats, skis, golf clubs, pool cues and hockey sticks must be checked. Sports balls can be carried on if they are examined and X-rayed by airport security.
