As of August 2014,TSA rules concerning liquid carry-ons were condensed to the 3-1-1 rule, which states that liquids, gels, aerosols, creams and pastes must be 3.4 ounces or lighter per container. In addition, they must be contained in a single, clear, quart-sized zip-top bag per passenger.
Many items are prohibited from carry-on luggage, though some versions may be permitted in checked luggage. The full list of banned items, along with exceptions and explanations, is available at the TSA website. In general, any object that might be hazardous or threatening is prohibited from carry-on, such as sharp objects, sporting goods, guns and firearms, tools, martial arts and self defense items, explosive and flammable materials, disabling chemicals and other dangerous items.
Other items that are prohibited include gel-type candles, several types of paint and snowglobes containing more than 3 ounces of liquid or which don't fit into the approved transparent liquids bag for carry-on.
Around the same time the 3-1-1 rule was instituted, the TSA also issued guidance to its staff that electronic devices should be checked to make sure they are genuine. This means travellers must make sure that all such devices are charged and working to comply with these checks.