All required hazardous materials warning labels and markings must be placed on the address side of the package. Only in limited situations where sufficient space does not exist, DOT markings may be placed on a side adjacent to the address. Markings and labels must not be placed on the bottom of a package or envelope. Other markings required by the Postal Service or other federal regulatory agencies also must appear on the address side of any mailpiece containing hazardous material, restricted matter, or perishable matter. Specific text markings that are required, must be printed on the address side of the package.
All DOT hazardous materials warning labels and markings must be:
- Displayed on the same surface of the package and near the proper shipping name.
- Displayed next to each other (within six inches) when more than one marking or label is required.
- Printed on or affixed to a background of contrasting color or must have a dotted or solid line outer boundary.
- Clearly visible; and not obscured by any mark or attachment.
- Durable and weather-resistant.
- Oriented as a diamond (square-on-point).
- At least 100 mm (3.9 inches) on each side, unless specified in 325.1 and 325.4.
- Printed with solid line inner border at least 5mm inside and parallel to the edge, and the border widths must be at least 2 mm.
Limited Quantity or UN3373 markings may be permitted to be displayed at a reduced size with special authorization from the manager of Product Classification. (see 214 for address).
In commerce, packages containing hazardous materials must display the appropriate DOT hazardous materials warning label and markings. Except as provided in Exhibit 325.3, any mailpiece bearing or required to bear one of the labels shown in Exhibit 325.2 under 49 CFR, is prohibited from mailing.
Note: The labels shown in the exhibits are not shown to size. DOT warning labels must meet the size and color requirements in 49 CFR §172.407 through 172.446 unless special authorization from the Manager, Product Classification is obtained as outlined in 325.1.
DOT Hazardous Materials Warning Labels: PROHIBITED IN THE MAIL
The warning labels shown in Exhibit 325.3a, Exhibit 325.3b, 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.
DOT Hazardous Materials Warning Labels: PERMITTED ON MAILABLE HAZARDOUS MATERIALS
DOT Hazardous Material Warning Labels: PERMITTED FOR MAILABLE LIMITED QUANTITIES ONLY
Unless specified in 221.1 and 325.1, each mailpiece containing a mailable hazardous material must be plainly and durably marked on the address side with the required shipping name and UN identification numbers. Requirements for the use of DOT Limited Quantity markings intended for air and surface transportation are as follows:
- Marking description: The top and bottom portions of the square-on-point marking and the border forming the square-on-point marking must be black and the center must be white or of a suitable contrasting background. See Exhibit 325.4.
- Markings must be durable, legible, and readily visible.
- The border forming the square-on-point marking must be at least 2 mm (0.08 inch) in width and the minimum dimension of each side of the marking must be 100 mm (3.94 inches), unless the package size requires a reduced size marking of no less than 50 mm (1.97 inches) on each side.
- The application of a smaller size (50 mm or 25 mm with a DOT-Special Permit) Limited Quantity mark on packages regardless of the size are permitted with restrictions and require a prior written approval from the manager of Product Classification (see 214 for address).
- For transportation by aircraft, the air Limited Quantity mark must have the symbol ‘‘Y’’ in black color inside the center of the square-on-point mark and be clearly visible. Mailpieces intended for transport by air must also be marked with the proper shipping name and identification number, and display the appropriate DOT-associated marking when required for the hazard class shipped in accordance in this publication.
- For surface transportation, a Limited Quantity ground mark (square-on-point) is not required to include the proper shipping name and identification number.
DOT Hazardous Material Warning Labels: PERMITTED FOR LIMITED QUANTITY SQUARE-ON-POINT
Hazardous materials eligible to be shipped under the excepted quantity provision, as described in 49 CFR 173.4a and 337.2, must be prepared following Packaging Instruction 10B in Appendix C. Each mailpiece must bear a DOT-approved excepted quantity marking, shown in Exhibit 325.4, under the following conditions:
- The “*” must be replaced by the primary hazard class, or when assigned, the division of each of the hazardous materials contained in the package.
- The “**” must be replaced by the name of the mail owner or mail service provider if not shown elsewhere on the package.
- The marking must be located on the address side of the mailpiece, not be less than 3.9 inches (100 mm) by 3.9 inches (100 mm), and must be durable and clearly visible.
Excepted Quantity Marking