USPS Homepage

725 Mailer Responsibility

725.1 General

Full responsibility rests with the mailer to comply with all Postal Service and non–Postal Service laws and regulations regarding the mailing of hazardous materials. Anyone who mails, or causes to be mailed, a nonmailable or improperly packaged hazardous material can be subject to legal penalties, including, but not limited to, those specified in 18 U.S.C.

725.2 Warning Labels and Marking Requirements

Except as noted, hazardous materials acceptable for air transportation generally fall within the consumer commodity or mailable limited quantity categories. Mailpieces containing these materials and intended for air transportation have specific marking requirements, including the use of certain DOT hazard class warning labels. Some air-eligible mailable hazardous materials also have marking and packaging requirements that are unique to mailpieces entered under these exceptions (e.g. SP 9275, certain mailable infectious substances and medical waste, and dry ice). Mailable hazardous material must bear DOT handling labels (such as orientation arrows, magnetized materials, etc.) when applicable. The following also apply:

  1. Mailpieces containing air-eligible materials in hazard Classes 2, 3, and 6.1, or portions of 9 must bear DOT square-on-point markings and an approved DOT Class 9 hazardous material warning label (see
    Exhibit 325.2b). The top and bottom portions of the square-on-point and the border forming the square-on-point must be black, and the center must be white or of a suitable contrasting background. The symbol “Y” must be black, located in the center of the square-on-point, and clearly visible. Mailpieces must also be marked with the proper shipping name “Consumer Commodity” and identification number “ID8000.” A shipper’s declaration for dangerous goods, prepared in triplicate, must be affixed to the outside of the mailpiece.
  2. Mailpieces containing air-eligible materials in hazard Classes 5.1, 5.2, or 8 must bear a DOT square-on-point marking and the appropriate approved DOT Class 5.1, 5.2, or 8 hazardous material warning label. The top and bottom portions of the square-on-point and the border forming the square-on-point must be black, and the center must be white or of a suitable contrasting background. The symbol “Y” must be black, located in the center of the square-on-point, and clearly visible. Mailpieces must also be marked with the appropriate identification number and the proper shipping name. A properly completed shipper’s declaration for dangerous goods must be affixed to the outside of the mailpiece.
  3. Markings must be durable, legible, and readily visible, and must be applied on at least one side or one end of the outer packaging. The border forming the square-on-point must be at least 2 mm in width, and the minimum dimension of each side must be 100 mm, unless the package size requires a reduced size marking of no less than 50 mm on each side.

725.3 Shipping Papers

Most mailable hazardous materials (including consumer commodity materials or mailable limited quantity materials) must be accompanied by a Shipper’s Declaration for Dangerous Goods (shipping paper, see 326). To determine which mailable hazardous materials require a shipping paper when sent via air transportation, refer to the appropriate sections in Chapter 3, and the appropriate Packaging Instruction in Appendix C.

The shipping paper must be properly completed and signed in triplicate by the mailer. It must bear a red candy–striped border and the exact format and same basic wording as shown in Exhibit 326. The shipper’s declaration must be properly prepared, as required by 49 CFR 172.200 through 172.205, which, in part, requires the following information:

  1. Proper shipping name of material.
  2. Hazard class.
  3. UN or NA identification number, as applicable.
  4. The quantity and type of packaging.
  5. The packaging instruction used.
  6. The full name, address, and telephone number of the shipper or consignee.
  7. The signed shipper’s certification statement.

Neither the Postal Service nor DOT stocks or furnishes shipper’s declaration forms. Mailers may obtain them from commercial printers, Internet–based retailers, safety supply stores, or stationery stores.

725.4 Addressing

The full names and addresses of both the sender and the addressee must appear legibly on the address side of the mailpiece, in accordance with DMM 602.