The Transportation Security Administration (TSA) prohibits sharp objects, sporting goods, guns and firearms, tools, martial arts and self-defense items, explosive and flammable materials and disabling chemicals, along with a number of other dangerous items from all carry-on luggage. Most items are permitted in checked luggage; however, there are a number of key exceptions: flares, gun lighters, gunpowder, any explosive materials, any flammable items, including aerosols and paint, and any disabling chemicals except small compressed gas cartridges used for life vests.
Up to two fueled common lighters may be taken in carry-on luggage, provided they are approved by the Department of Transportation. As of May 2015, this means they may not be torch lighters, and they must be made by either Zippo Manufacturing Co., The Colibri Group or Prometheus International, Inc. The TSA recommends leaving lighters at home if there is any uncertainty as to their admissibility. No lighters may be carried in checked luggage.
When transporting sharp objects in checked luggage, they must be sufficiently wrapped or sheathed so as to eliminate the possibility of harm to baggage handlers. Some specific examples of sharp objects prohibited from carry-on luggage but permitted in checked luggage are ice picks, sharp knives, scissors with blades longer than 4 inches and swords.