• Bulk packages are required to have specific markings for various types of high-temperature or radioactive materials, as well as medical waste and LPG.

Elevated-temperature materials

Most bulk packages that contain an elevated-temperature material must be marked on two opposing sides with the word “HOT” — in black or white Gothic lettering on a contrasting background. This marking must be displayed on the packaging itself or in black lettering on a white square-on-point configuration that is the same size as a placard.

Bulk packages that contain molten aluminum or molten sulfur must be marked “MOLTEN ALUMINUM” or “MOLTEN SULFUR” as appropriate, instead of with the word “HOT.

For bulk packages that must be marked “HOT,” “MOLTEN ALUMINUM,” or “MOLTEN SULFUR,” the letters must be at least:

• 3.9 inches (100 mm) for rail cars,
• 1 inch (25 mm) for portable tanks with capacities of less than 1,000 gallons (3,785 L), and
• 2 inches (50 mm) for cargo tanks and other bulk packages.

The Hazardous Materials Regulations (HMR) allows the “HOT” marking and identification number marking to be combined on the same white square-on-point configuration (Placard). In this case, the identification number must be displayed in the center of the white square-on-point configuration, and the word “HOT” must be displayed in the upper corner. The word “HOT” must be in black letters having a height of at least 2 inches (50 mm).

Radioactive materials (172.310)

Each package containing Class 7 (radioactive) materials must also be marked with:

• Gross mass if the gross mass of the package exceeds 110 pounds (50 kg);
• TYPE A or TYPE B, as appropriate;
• For TYPE B(U) or B(M), the appropriate radiation symbol according to Appendix B to Part 172; and
• USA in conjunction with the specification marking, if the package is destined for export.

Regulated medical waste (172.323)

A bulk packaging containing a regulated medical waste must be marked with the “BIOHAZARD” marking, visible from the direction it faces:

• On two opposing sides or ends if the packaging has a capacity of less than 1,000 gallons (3,785 L), or
• On each end and each side if the packaging has a capacity of 1,000 gallons (3,785 L) or more.

The “BIOHAZARD” marking must be at least 6 inches (152.4 mm) on each side. This marking may be displayed on a white square-on-point configuration.

Non-odorized LPG (172.301, 172.326, 172.328, 172.330)

No person may offer or transport certain specification cylinders, a portable tank, cargo tank, or tank car containing liquefied petroleum gas (LPG) that is not odorized unless the words “NON-ODORIZED” or “NOT ODORIZED” appear near the proper shipping name. This marking must appear on two opposing sides on portable tanks, cargo tanks, and tank cars.