Mailers:

• Must know the physical characteristics of the hazardous materials they wish to mail.
• Are responsible for ensuring that they do not mail any hazardous material that can injure persons or property unless the hazardous material is permitted under the mailing standards in the Mailing Standards of the United States Postal Service, Domestic Mail Manual (DMM^®) 601.10. Further guidance on domestic, international, and APO/FPO mailability is available from Publication 52, Hazardous, Restricted, and Perishable Mail. The Mailing Standards of the United States Postal Service, International Mail Manual (IMM^®) contains the standards that apply to hazardous materials intended for foreign addresses.
• May reuse packaging and boxes when all markings and labels are removed or completely marked out. Regardless of what is actually inside your package, markings or labels for hazardous materials may result in delivery delays or a package return.