Almost all hazardous materials are prohibited in international mail. The only mailable hazardous materials are certain infectious substances, excepted quantities of radioactive material that are allowed in domestic mail, certain magnetized materials, and certain lithium and lithium-ion batteries. See Exhibit 621.1 for a summary of the types of hazardous materials that are eligible for mailing in international mail.
In certain situations, the few types of hazardous materials that are generally permitted in international mail may be further restricted by the mailing limitations imposed by an individual country. Because individual countries have unique prohibitions and restrictions, it is always necessary to consult the Individual Country Listings in the IMM to be certain that an otherwise mailable hazardous material is acceptable for shipment to a specific country.
The non–Postal Service regulations that govern the air shipment of hazardous materials (dangerous goods) in international commerce are specified in the Technical Instructions for the Safe Transport of Dangerous Goods by Air of the International Civil Aviation Organization (ICAO). In 49 CFR, DOT recognizes ICAO requirements for the air transportation of hazardous materials. However, 49 CFR gives DOT the authority to regulate only the domestic transportation of hazardous materials. Generally, most air carriers follow the Dangerous Goods Regulations of the International Air Transport Association (IATA), and those regulations are slightly more restrictive than the ICAO rules.
The Consumer Commodity, Mailable Limited Quantity, and ORM-D classifications are unique within domestic commerce in the United States and are not recognized in international commerce. Hazardous materials under these classifications that are mailable in domestic mail are typically prohibited in international mail.
Hazardous, restricted, or perishable materials mailed to, from, and between overseas military Post Offices are subject to the conditions of IMM 130, the standards in this publication, conditions prescribed by the Department of State international security policy, and conditions prescribed by the Department of Defense (DOD), as listed in Overseas Military/Diplomatic Mail in the Postal Bulletin. Also see DMM 703.2-4.