The mark must indicate UN3480 for lithium-ion cells or batteries. The mark must also include a telephone number for those who need to obtain additional information.

USPS Packaging Instruction 9E Lithium Metal and Lithium-ion Cells and Batteries — International and APO/FPO/DPO

All hazardous materials eligible to be sent as Parcel Select Lightweight or USPS Ground Advantage must be prepared under the requirements that apply to surface transportation.

Toggle navigation Publication 52 - Hazardous, Restricted, and Perishable Mail. Publication 52 - Hazardous, Restricted, and Perishable Mail; Summary of Changes

Where the lithium cells or batteries are shipped separately from equipment, the mark must indicate UN3480. Where the lithium cells or batteries are contained in, or packed with, equipment, UN3481 must be indicated.

Toggle navigation Publication 52 - Hazardous, Restricted, and Perishable Mail. Publication 52 - Hazardous, Restricted, and Perishable Mail; Summary of Changes

Appendix B Numerical Listing of Proper Shipping Names by Identification (ID) Number. This appendix contains a numerical list of the United Nations (UN) and North American (NA) ide

322 Postal Service; 323 Mailer Responsibility; 324 Mailability Rulings; 325 DOT Hazardous Materials Warning Labels; 326 Shipping Papers; 327 Transportation Requirements; 328 Postal Service Hazardous Materials Table; 329 Presentation of Hazardous-Materials Mailings; 33 Hazard Classes . 331 Nine Classes; 332 Limited Quantity

The Postal Service is reminding customers that metallic mercury and devices containing metallic mercury are always prohibited in the mail stream. This includes antique items such as thermometers, barometers, blood pressure monitors and similar devices.

The warning labels shown in Exhibit 325.3 a, Exhibit 325.3 b, and Exhibit 325.4 may appear only on mailpieces containing mailable hazardous materials that require use of the label under Postal Service requirements. Division 5.1, 5.2, Class 8 and Class 9 labels are only permitted when used in conjunction with a Limited Quantity air mark.