Miscellaneous hazardous materials fall under Class 9 in the DOT hazardous materials classification system, and they use the Class 9 placard. This placard features a white background with seven black vertical stripes across the upper half and the number “9” in the bottom corner, all displayed in a diamond (square-on-point) orientation. The regulatory specifications for this placard are found in 49 CFR §172.560.
What the Class 9 Placard Looks Like
The Class 9 placard is visually distinct from other hazmat placards. Instead of a pictogram representing a hazard type (like a flame for flammables or a skull for toxics), the upper half displays seven evenly spaced black vertical stripes on a white background. The lower half is plain white with a large “9” printed in black near the bottom point of the diamond. There is no color coding beyond black and white, which reflects the “miscellaneous” nature of the hazard: these materials don’t fit neatly into a single hazard category like flammability or corrosion.
What Counts as a Miscellaneous Hazardous Material
Class 9 is essentially a catch-all category for hazardous materials that present a danger during transport but don’t meet the definitions of Classes 1 through 8. Common examples include dry ice, lithium batteries, magnetized materials, elevated temperature substances, environmentally hazardous substances, asbestos, and life-saving appliances like automobile airbags and self-inflating life vests.
The category also covers any material with anesthetic or noxious properties that could cause extreme annoyance or discomfort to a flight crew member, as well as hazardous substances, hazardous waste (other than infectious medical waste), and marine pollutants.
When the Class 9 Placard Is Required
Placarding rules for Class 9 differ from most other hazard classes because of a domestic transportation exception. A Class 9 placard is not required for domestic highway or rail shipments of non-bulk packages. This exception applies to transportation occurring entirely within the United States, including the domestic leg of an international shipment.
However, bulk packaging containing a Class 9 material must be marked with the appropriate UN identification number displayed on a Class 9 placard, an orange panel, or a white square-on-point configuration. So if you’re shipping a large tank or intermodal container of a miscellaneous hazardous material, the placard requirement still applies.
For non-bulk shipments, Class 9 falls under Table 2 of the general placarding requirements in 49 CFR §172.504. Table 2 materials are exempt from placarding on a transport vehicle or freight container carrying less than 454 kg (1,001 pounds) aggregate gross weight. Above that threshold, placarding would normally apply, but the domestic exception for Class 9 overrides this for shipments within the U.S. For international movements, the Class 9 placard is required.
Labels for Individual Packages
While placards go on the outside of transport vehicles and freight containers, labels go on individual packages. The Class 9 label uses the same visual design as the placard: black vertical stripes over white with a “9” at the bottom. The standard hazmat label is a 100mm by 100mm (roughly 4-inch by 4-inch) diamond applied to the outer surface of the package near the proper shipping name and UN identification number.
Lithium Battery Labeling Specifics
Lithium batteries are one of the most commonly shipped Class 9 materials, and they have their own layered set of marking and labeling rules depending on battery size and mode of transport.
Fully regulated lithium batteries (larger cells and battery packs) require the Class 9 lithium battery label on each package, along with the proper shipping name (such as “Lithium ion batteries”), the UN identification number (UN3480, UN3481, UN3090, or UN3091), and shipper and recipient name and address. Shipments going by cargo aircraft also need a Cargo Aircraft Only label.
Smaller lithium batteries that qualify for exceptions under 49 CFR §173.185(c) use a different mark instead of the full Class 9 label. This lithium battery mark is a rectangle or square with hatched edging, measuring at least 100mm by 100mm (3.9 inches square). A smaller version, 100mm by 70mm, is permitted when the package is too small for the standard mark. The mark must display the UN identification number for the battery type.
A rule change effective May 10, 2024, requires the watt-hour (Wh) rating to be marked on the outside case of all lithium ion batteries regardless of size. The same rulemaking removed the telephone number requirement from the lithium battery mark, with a phaseout date of December 31, 2026, meaning existing marks with telephone numbers can still be used until then.
The size thresholds for “smaller” battery exceptions vary by transport mode. For lithium ion batteries shipped by any mode, cells must be 20Wh or less and batteries 100Wh or less. For highway and rail only, those limits expand to 60Wh per cell and 300Wh per battery. Lithium metal cells must be 1g or less (5g for highway and rail), and batteries 2g or less (25g for highway and rail).
Proper Placement on Vehicles
When placards are required, they must be displayed on all four sides of a transport vehicle or freight container: front, back, and both sides. Each placard must be clearly visible, not obscured by ladders, doors, or other equipment. For cargo transport units carrying lithium batteries installed in equipment (UN3536), the Class 9 placard is required on at least two opposing sides, and the UN identification number 3536 must appear on an orange panel, white square-on-point display, or directly on the placard.
Placards must be durable enough to withstand weather and handling during transport. They are typically made of tagboard, plastic, or metal and must meet the size requirement of at least 273mm (10.8 inches) on each side when displayed in the diamond orientation.