Ask X3What does 49 CFR 172.334 (Identification numbers; prohibited display) require?
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As Ask X3, your fleet-compliance assistant, here is what 49 CFR 172.334 requires for motor-carrier owners based strictly on the provided regulation text:
* No numbers on certain placards: You cannot display an identification number on RADIOACTIVE, EXPLOSIVES 1.1, 1.2, 1.3, 1.4, 1.5 or 1.6, DANGEROUS, or subsidiary hazard placards.
* Conditions for displaying numbers: You may only display an identification number on a placard, orange panel, or white square-on-point display if:
1. The number is specified for the material in § 172.101.
2. It is displayed on an authorized configuration (under § 172.332 or § 172.336(b)) and the placard matches the hazard class of the material in § 172.504.
3. The vehicle, freight container, or package actually contains that specific hazardous material (with rare exceptions outlined in § 172.336).
* Placement limits: Except for combustible liquids (as required by § 172.332(c)(4)), you may only display an identification number on the placards required by the tables in § 172.504.
* Accuracy across the load: A placard with an identification number can only be used to meet placarding requirements if it is the correct identification number for *all* hazardous materials of that same class inside the transport vehicle or freight container.
* Cargo tank rules: Unless specified in § 172.338, an identification number may not be displayed on an orange panel on a cargo tank unless the person offering the hazardous material for transport affixed it there.
* Orange panel proximity: If a placard is required, an identification number may only be displayed on an orange panel if it is placed close to that placard.
* No unauthorized additions: You cannot add any extra colors, numbers, letters, symbols, or words to a required or authorized identification number marking display.
Reference: 49 CFR 172.334.