A question posted to a Yahoo! Group back in November 2015:

Comparing notes.

For shipments in the U.S.
For shipments of hazardous materials that require placards of truck load of non-bulk packages, you are allowed to use the Dangerous placard in place of multiple hazard class placards (under certain conditions).

Can you you use the Dangerous placard if the load is only one Hazrad Class?

Same question for Canada for the Danger placard?

Thanks in advance.

Someone gave a reply before I did the next day:

49CFR 172.504 (b) DANGEROUS placard: …….”non-bulk packages with two or more categories of hazardous materials that require different placards specified in table 2 of paragraph (e) of this section may be placarded with a DANGEROUS placard instead of the separate placarding specified for each material…..”

So, it has to be 2 different hazards.  Also, can’t be used to substitute placarding from Table 1, and can’t be used if 1,000 kg (2205#’s) or more of ONE hazard class is loaded at one facility.

Here’s my reply just a few hours earlier:

I cannot speak with certainty about the Canada regulations, but I know that in the U.S. PHMSA/USDOT does not allow the use of the Dangerous Placard if there is only one HazMat on the vehicle.

I hope I contributed something valuable to the conversation.