What are hazmat package markings? By definition, markings can be a descriptive name, UN identification number (some are on placards or orange panels), instructions, cautions, weight, and package specification. Markings can also be UN marks (such as UN package identification code), or any combination required by the regulations on the outer packaging of hazardous materials. Marking on the outside of packages communicates the presence of the hazardous materials inside.

Unless there's an exception in the regulations, a package is required to have markings displayed on the outside. When markings are required, there are also certain rules on how the marking has to be maintained (such as durability and legibility), minimum size requirements and times when the display for certain markings may be prohibited for bulk packages. Even the hazardous material itself may require an additional marking, such as a material that is poisonous by inhalation. The regulations also dictate how the marking has to appear on the packaging or transport vehicle, so make sure you consult the regulations on marking display. After all, it wouldn't do any good to place a marking on the bottom of the package where nobody can see it right?

When determining whether or not a package has to marked and what kind of markings have to be on the package itself, it's important that the hazmat shipping papers are looked at. Again, this re-emphasizes the importance of well prepared shipping papers. If shipping papers are prepared wrong it can start an avalanche of other violations! If you put the wrong UN identification number on the shipping papers, then you may have the wrong identification number on the package. So now you have two violations on an  inspection report -  a shipping papers violation and a marking violation. If the transport vehicle itself was required to be marked with the UN number, and it's marked wrong, that vehicle may be placed out of service.

Once you've looked at the shipping papers, take a close look at the quantity to determine whether you're hauling a bulk or non bulk amount of hazmat. If the material meets the definition of non bulk, then the general requirements of 172.301 (non bulk requirements) will apply. If the hazmat meets the definition of bulk, then the requirements for bulk packages in 172.302 will apply. Keep in mind that these are just the basic requirements for bulk and non bulk markings, and there may be more requirements that apply to the package.