623 Nonmailable Hazardous Materials

The following types of hazardous materials, as defined in Chapter 3, and IMM 135–136, are prohibited in international mail:

1. Class 1, explosives (including explosive devices) (341).
2. Class 2, gases (342).
3. Class 3, flammable and combustible liquids (343).
4. Class 4, flammable solids including matches (344).
5. Class 5, oxidizing substances and organic peroxides (345).
6. Class 6, Division 6.1, toxic substances (including irritants) (346).
7. Class 6, Division 6.2, infectious substances (346), except as permitted in 622.2.
8. Class 7, radioactive materials (347), except as permitted in 622.3.
9. Class 8, corrosives (348).
10. Class 9, miscellaneous hazardous materials (349).
11. Dry ice (carbon dioxide solid) (349.23).
12. Magnetized materials capable of causing a compass deviation at a distance of 7 feet or more (349.24). See 622.4 for mailable magnetized materials.