Class 9 hazardous materials (hazmats) is the catch-all class for hazmats that don’t fit neatly into any of the Class 1–8 descriptions. Instead of a definitive moniker such as “corrosives” or “explosives,” Class 9 hazmats are saddled with “miscellaneous” to describe their attributes. This is due to Class 9 covering a wide range of materials, such as hazardous substances, elevated temperature materials, some hazardous wastes, and marine pollutants.

Like Classes 1–8, Class 9 hazmats present a hazard during transportation. While shipments of Class 9 hazmats seem to raise all sorts of questions, such as “Is every material that’s a Class 9 hazmat listed on the hazmats table?” (answer: no) and “Can a Class 9 material qualify for a limited quantities exception?” (answer: yes), the question that seems to concern many shippers is “Does a Class 9 shipment have to be placarded?” Like the other classes, Class 9 hazmats have been assigned a placard, but that doesn’t necessarily mean that the placard must be used on a Class 9 shipment.

When a Class 9 placard is not needed

General rule. The general placard rule of the U.S. Department of Transportation (DOT) hazardous material regulations (HMRs) is that each bulk packaging, freight container, unit load device, transport vehicle, or rail car containing any quantity of a hazmat must be placarded on each side and each end.  The type of placards must be appropriate to the shipment and as specified in 49 CFR 172.504 and in other HMRs. But this same regulation specifies an exception for a Class 9 shipment: The Class 9 placard is not required for domestic transportation of either non-bulk or bulk shipments. However, although a Class 9 shipment does not need a placard in the United States, it may still need to be marked.

Bulk shipments. Bulk shipments of Class 9 hazmat, for example, while not requiring a placard, must still be marked with the applicable United Nations (UN) number. The UN number must be marked on an orange panel, a white square-on-point display configuration or on a Class 9 placard (shipper’s choice). Regardless of whether the Class 9 placard is used to display the UN number, the UN number must be displayed on all four sides of the bulk packaging. However, if the UN number marking is not visible on bulk packaging contained in or on a transport vehicle or a freight container, the transport vehicle or freight container must be marked on each side and each end with the UN number.

Non-bulk shipments. Similarly, the HMRs at 49 CFR 172.301 require a transport vehicle or freight container that encloses 4,000 kilograms (kg)(8,820 pounds) or more of a single hazmat in non-bulk packages to be marked on each side and each end with the identification number of the hazmat. This only applies when the entire shipment of non-bulk packages has the same proper shipping name and is loaded at the same facility

When a Class 9 placard is needed

The Class 9 placard is required for international shipments, although not for any part of the transportation that occurs in the United States. If any other class of hazmat is on the shipment with the Class 9 material, the appropriate placard would be needed for that additional hazmat class.

Can a Class 9 placard be used even if not needed?

Yes. Many shippers feel more comfortable if they attach a placard to their Class 9 hazmat shipment with the applicable UN number. The DOT does not prohibit its use.