As shown on the shipping paper, after the proper shipping name.
Total weight of all hazardous materials of this type on the vehicle, including packaging — not the weight of a single package.
How this works
49 CFR 172.504 splits hazardous materials into two tables, and the table a material falls into decides whether quantity matters at all.
Table 1 materials require placards in any quantity — there is no threshold. These are the materials where a small release is catastrophic: mass-explosion explosives, poison inhalation gases, dangerous-when-wet solids, temperature-controlled organic peroxides, inhalation-hazard toxics in Zones A and B, and Yellow III radioactives.
Table 2 materials — everything else — require placards only once the aggregate gross weight of hazmat on the vehicle reaches 454 kg (1,001 lbs). Below that, no placard, though shipping papers and proper packaging still apply.
Bulk packaging overrides the weight question. Any bulk container of a regulated material is placarded regardless of how much is inside, and that includes an unpurged empty.
Class 9 is the exception most people miss: Class 9 placards are not required for domestic US highway transport under 172.504(f)(9), though bulk packagings must still display the identification number.
What this tool does not do
- It does not classify your material. The hazard class comes from the shipper's determination and the hazmat table — not from this calculator.
- It does not handle the DANGEROUS placard substitution rule, subsidiary hazards, or mixed loads of several Table 2 classes.
- It does not cover state-specific or local routing overlays.
This is an educational aid, not a compliance determination. Verify every shipment against the current text of 49 CFR 172.504 and the hazardous materials table in 172.101. The regulations change; this page may lag them.
Related guides
- Hazmat Placard Requirements: A Complete DOT Guide
- Class 3 Flammable Liquids Transport Requirements
- DOT Diesel Fuel Placard Requirements
- Lithium Battery Shipping Requirements
- IBC Tote Transport Requirements
Use this tool on your own site
Trainers, compliance consultants and fleet safety teams are welcome to link to this calculator. A link back to ustruckingstandards.com is all we ask. More free diagrams and reference material is on our resources page.