Mailing Standards of the United States Postal Service, International Mail Manual > 1 International Mail Services > 130 Mailability > 136 Nonmailable Goods
Except as provided in IMM 135, “dangerous goods” as defined by the United Nations Recommendations on the Transport of Dangerous Goods, Model Regulations, are prohibited in outbound international mail, regardless of mail class. Some examples of dangerous goods include the following:
- Explosives or explosive devices.
- Flammable materials.
- Pyrophoric, flammable, or combustible liquids with a closed cup flash point below 200°F.
- Flammable solids, including matches.
- Corrosives, liquid or solid.
- Compressed gases.
- Nonflammable with an absolute pressure exceeding 40 psi at 70°F or 104 psi at 130°F.
- Poisons, irritants, controlled substances, and drug paraphernalia.
- Magnetized material with a magnetic field strength of .002 gauss or more at a distance of 7 feet.
- Dry ice (carbon dioxide solid).
Additional information on dangerous goods is available at unece.org/trans/danger/danger.html.
The following types of inert or replica explosive devices are prohibited in outbound international mail:
- Military ordnance, ammunition, and shells.
- Similar devices that were originally designed for military or combative use (including training).
This prohibition does not extend to items such as children’s toys or articles that do not represent the above items in a realistic manner.
Any type of counterfeit or pirated article is prohibited in outbound international mail.
Cigarettes (including roll-your-own tobacco) and smokeless tobacco products as defined in Publication 52, part 471 are nonmailable when sent in outbound or inbound international mail. The exceptions for mailing under Publication 52, section 472.2 are not available for shipments of such products in international mail. This standard prevails regardless of any information to the contrary in the Individual Country Listings.