"We're Under 1,001 Pounds, So No Placards"
You are assigned a straight truck with a lift gate for a run from a Sarasota distributor to a job site in Naples. The load sheet shows:
- 1 cylinder of propane, UN1978, Division 2.1, 20 lb gross
- 15 pails of UN1263, Paint, Class 3, PG II, 60 lb each (900 lb)
- 4 drums of UN1789, Hydrochloric acid, Class 8, PG II, 120 lb each (480 lb)
Everything is non-bulk, and all of it is loaded at the distributor in one place at one time. The dispatcher tells you, "Total is 1,400 lb, but the rules look at each class separately and none of them is over 1,001, so we're clean - no placards." The truck has four flat placard holders on the sides, front, and rear. There is a spare CORROSIVE placard in the cab from a previous run.
1. State exactly which placards are required on this truck and explain how the thresholds produce that answer.
Read the worked answer
Two different threshold rules apply, and the dispatcher has applied neither correctly.
The propane is a Division 2.1 material in the Table 1 group, which requires placards for any quantity. Twenty pounds still means a FLAMMABLE GAS placard. There is no 1,001-lb floor for Table 1.
For Table 2 materials, placards are required when the aggregate gross weight of all Table 2 materials loaded at one place at one time reaches 1,001 lb - the weights are added across hazard classes, not measured class by class. Here 900 lb of Class 3 plus 480 lb of Class 8 totals 1,380 lb, which crosses the threshold. Placards are then required for each Table 2 hazard class present: FLAMMABLE (Class 3) and CORROSIVE (Class 8).
Because two or more Table 2 categories are present at or above 1,001 lb, the DANGEROUS placard may be displayed instead of the FLAMMABLE and CORROSIVE placards. It cannot replace the Table 1 FLAMMABLE GAS placard. Acceptable configurations: FLAMMABLE GAS + FLAMMABLE + CORROSIVE, or FLAMMABLE GAS + DANGEROUS. All placards go on both sides, the front, and the rear, on point, at least 250 mm on each side, legible from the direction they face.
2. The dispatcher offers to "just put the spare CORROSIVE placard on and skip the rest so it looks covered." Evaluate that proposal.
Read the worked answer
It is worse than doing nothing, because it is affirmatively misleading.
A placard tells responders and inspectors what is on board and what to expect. Displaying CORROSIVE on a truck carrying 20 lb of propane and 900 lb of paint, with no FLAMMABLE GAS or FLAMMABLE placard, understates two hazards while overstating nothing - the Class 8 material is the smallest hazard on the vehicle. A responder who sees only CORROSIVE may approach from the wrong distance and with the wrong extinguisher if the cargo is burning.
There is also a compliance angle: placards must be displayed for every hazard that requires one, and displaying a placard for a hazard not present can itself be a violation. Partial placarding is not a mitigation strategy.
The correct move is the full set - FLAMMABLE GAS plus either FLAMMABLE and CORROSIVE, or DANGEROUS - applied to both sides, front, and rear before the truck leaves the yard. Note also that placards must be removed or covered when the vehicle no longer contains the material, so the old CORROSIVE placard in the cab should not be left stuck on the truck after this run.
3. If the four drums of acid were left behind, how would the placarding change? What does that tell you about how to plan the load?
Read the worked answer
Removing 480 lb of Class 8 leaves 900 lb of Table 2 material - the paint - which is below the 1,001-lb aggregate threshold. No FLAMMABLE or CORROSIVE placard would be required in that case, and the DANGEROUS option would not be available either, since it requires two or more Table 2 categories at or above the threshold.
The propane is unchanged. Twenty pounds of Division 2.1 material still requires a FLAMMABLE GAS placard, because Table 1 has no quantity threshold. A driver who assumes "small cylinder, no placard" would still be wrong on a load consisting only of that cylinder.
The planning lesson is that the placard decision has to be made from the actual loaded weights at the moment of departure, not from the order sheet. Adding or dropping one pallet can flip a Table 2 load from unplacarded to placarded. Before you sign, total the Table 2 weight across all classes, check separately for any Table 1 material, and then placard for each class present.