General Prohibited Items in Carry On Luggage
Most airlines and the Transportation Security Administration ban sharp objects, blunt instruments, and self-defense items from carry on bags. The TSA prohibits items that can be used as weapons, including box cutters, switchblades, and martial arts weapons. Firearms, ammunition, and explosive devices are strictly forbidden in cabin luggage, with violations leading to fines and criminal charges. The TSA website lists current prohibited items and updates the rules based on threat assessments and security research TSA Prohibited Items.
Flammable and reactive substances are also restricted, including gasoline, paint thinner, and aerosol cans larger than 3.4 ounces. Common consumer items like certain tools, sporting goods, and kitchen utensils are banned because they can cause harm during flight. Liquids, gels, and aerosols must follow the 3-1-1 rule, with containers limited to 3.4 ounces and placed in a single quart-sized clear bag. The FAA and TSA coordinate on these rules to reduce in-flight risks and maintain consistent security standards across U.S. airports.
Liquids, Electronics, and Restricted Devices
Liquids, gels, creams, and aerosols in carry on bags must comply with the 3-1-1 rule, and passengers must remove them for screening at checkpoints. Medically necessary liquids, baby formula, and breast milk are exempt but may require additional screening. Electronic devices larger than a cellphone must be placed in separate bins for X-ray screening, and some devices with large batteries face restrictions on capacity and watt-hour ratings. The International Air Transport Association and individual carriers publish guidance on battery-powered devices and spare lithium batteries IATA Travel Information.
Power banks and spare lithium batteries are allowed only in carry on luggage, not in checked bags, due to fire risk. Devices with non-removable batteries must be protected against accidental activation, and damaged or recalled devices may be prohibited entirely. The FAA and airlines restrict certain high-capacity batteries and require passengers to declare larger electronic equipment at security checkpoints. Airlines may impose additional limits on devices during specific flights or on certain aircraft types based on safety directives.
Airline-Specific Rules and Recent Regulatory Updates
Individual airlines enforce additional carry on restrictions beyond TSA rules, including limits on bag size, number of items, and special categories like sports equipment. Some carriers restrict heavy or oversized carry on bags, require gate checks for certain items, or ban specific devices based on fleet configuration. Low-cost carriers often apply strict size and weight limits and charge fees for non-compliant bags. The U.S. Department of Transportation and the FAA publish airline-specific guidance and enforcement actions DOT Air Consumer Protection.
Recent regulatory updates have focused on lithium battery safety, with the FAA and international regulators tightening rules on battery watt-hour limits and device labeling. Security directives from the TSA and TSA-like agencies in other countries require enhanced screening for certain electronic devices on flights from specific regions. Airlines and regulators publish temporary or permanent rule changes in response to threat intelligence and incident investigations. Passengers are advised to check the latest rules on the airline website and the TSA website before traveling TSA Travel Information.