Hazardous materials
Articles listed in the Department of Transportation's Hazardous Material Regulations and/or the IATA Dangerous Goods Regulations are restricted. These will only be accepted subject to advance arrangements and compliance with regulations.

For safety reasons, dangerous goods may not be packed in checked or carry-on baggage or taken on board with you. Restricted articles include but are not limited to:

Acid
Lighter fluid
Explosives
Flammable solids/liquids
Oxidizing materials
Corrosive materials
Compressed gases
Poisons
Etiologic agents
Radioactive materials
Irritating or incapacitating sprays
Mercury
Noxious materials
Briefcases and attaché cases with installed alarm devices

Call United® at 1-800-United-1 in the U.S. for more information about hazardous materials.