Placarding question.

Depends.
If it’s flammable + UN just the flammable with UN.
if it’s Environmental hazard too, need that one as well.
or Corrosive + Flammable etc

On a 4 compartment tank i once had 32 placards..

 

Depends, could you post a pic of the hazmat column of the BOL? I haul some hot pavement dressing with xylene mixed in. UN 3256 HOT but it's class 3 and 9 so I have to use class 9 3256 with class 3 flammable as well

 

The reference chart in the hazmat book will tell you exactly what placards you need to run for each specific UN# and hazard class. When in doubt it's a good rule of thumb to run placards, even if it's not a placardable amount. As long as the hazmat class and the UN# matches what's printed on the BOL.
For example if one hazmat class on the BOL requires placards + UN#, and another doesn't, it's ok to run placards for both types. The DOT won't pop you for over placarding, as long as the placarded classes match the paperwork.

 

Subsiderary hazards do require a 2nd placard. there are flammable liquids that are also inhalation hazards requiring the class 3 with UN number [tankwagon] and a class 2 inhalation hazard with skull and crossbones...Shipper needs to provide the correct product description onthe paperwork and the required placards, as needed.

 

What does the BOL say?
The placards must match the BOL and the shipper must provide them.

 

Post a pic of the bol.