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Hazardous Materials: Placarding

16 questions in the bank cover this topic. Everything below is drawn from the sources those questions cite.

Sources: 49 CFR 172.504, 49 CFR 172.505, 49 CFR 172.506, 49 CFR 172.519

What you need to know

172.504(a) requires placards on each side and each end, which means four placards.

Responders approaching from any direction must be able to identify the hazard before they reach the vehicle.

each bulk packaging, freight container, unit load device, transport vehicle or rail car containing any quantity of a hazardous material must be placarded on each side and each end

49 CFR 172.504

172.504(c)(1) sets 454 kg, which is 1,001 pounds, aggregate gross weight.

Note this exception does not apply to bulk packagings or to the Table 1 materials, which require placards at any quantity.

Except for bulk packagings and hazardous materials subject to § 172.505, when hazardous materials covered by table 2 of this section are transported by highway or rail, placards are not required on— (1) A transport vehicle or freight container which contains less than 454 kg (1001 pounds) aggregate gross weight of hazardous materials covered by table 2

49 CFR 172.504

172.504(b) allows the DANGEROUS placard where non-bulk packages of two or more different Table 2 categories are loaded.

It is a convenience for mixed loads, not a general substitute. They must require different placards.

A freight container, unit load device, transport vehicle, or rail car which contains 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 of the materials

49 CFR 172.504

172.504(b) requires the specific placard once 1,000 kg, which is 2,205 pounds, or more of one category is loaded at a single facility.

Past that quantity the specific hazard must be named rather than hidden behind DANGEROUS. Loaded at a single loading facility.

However, when 1,000 kg (2,205 pounds) aggregate gross weight or more of one category of material is loaded therein at one loading facility on a freight container, unit load device, transport vehicle, or rail car, the placard specified in table 2 of paragraph (e) of this section for that category must be applied.

49 CFR 172.504

172.504(f)(1) requires only the placard representing the lowest division number, which here is EXPLOSIVES 1.2.

Class 1 division numbering runs from most to least hazardous, so the lowest number communicates the worst case and subsumes the rest.

When more than one division placard is required for Class 1 materials on a transport vehicle, rail car, freight container or unit load device, only the placard representing the lowest division number must be displayed.

49 CFR 172.504

172.504(f)(2)(i) permits FLAMMABLE in place of COMBUSTIBLE on a cargo tank or portable tank.

The substitution goes one way only: it overstates the hazard rather than understating it.

A FLAMMABLE placard may be used in place of a COMBUSTIBLE placard on— (i) A cargo tank or portable tank.

49 CFR 172.504

172.504(f)(3) drops the NON-FLAMMABLE GAS placard where FLAMMABLE GAS or OXYGEN placards are already displayed.

The greater hazard is already communicated, so the lesser placard adds nothing. And the vehicle is placarded FLAMMABLE GAS or OXYGEN.

A NON-FLAMMABLE GAS placard is not required on a transport vehicle which contains non-flammable gas if the transport vehicle also contains flammable gas or oxygen and it is placarded with FLAMMABLE GAS or OXYGEN placards, as required.

49 CFR 172.504

172.504(d)(1) excludes residue-only non-bulk packages from the placarding calculation, except for materials subject to 172.505.

Note bulk packagings are treated differently and a residue-bearing cargo tank stays placarded.

a non-bulk packaging that contains only the residue of a hazardous material covered by Table 2 of paragraph (e) of this section need not be included in determining placarding requirements

49 CFR 172.504

172.505(a) requires the inhalation hazard placard in addition to, not instead of, whatever 172.504 already requires.

Subsidiary hazard placarding adds information rather than replacing it. In addition to any other placard required.

Each transport vehicle, freight container, portable tank, unit load device, or rail car that contains a poisonous material subject to the “Poison Inhalation Hazard” shipping description of § 172.203(m) must be placarded with a POISON INHALATION HAZARD or POISON GAS placard, as appropriate, on each side and each end, in addition to any other placard required for that material

49 CFR 172.505

172.505(c) requires DANGEROUS WHEN WET on all four faces in addition to the primary placards.

The hazard matters to responders because applying water would make the incident worse. These are in addition to the placards 172.504 already requires.

Each transport vehicle, portable tank, freight container or unit load device that contains a material which has a subsidiary hazard of being dangerous when wet, as defined in § 173.124 of this subchapter, shall be placarded with DANGEROUS WHEN WET placards, on each side and each end, in addition to the placards required by § 172.504.

49 CFR 172.505

172.506(a) places the duty on the offeror, the shipper, to provide the placards before or when the material is offered, unless the vehicle already carries the correct placards.

Each person offering a motor carrier a hazardous material for transportation by highway shall provide to the motor carrier the required placards for the material being offered prior to or at the same time the material is offered for transportation

49 CFR 172.506

172.506(a)(1) prohibits the carrier from transporting without the required placards affixed.

The shipper's failure to supply them is not a defense; the duties run in parallel and both must be met.

No motor carrier may transport a hazardous material in a motor vehicle, unless the placards required for the hazardous material are affixed thereto as required by this subpart.

49 CFR 172.506

172.519(a)(1) sets a 30-day open weather standard.

A placard that has faded or peeled no longer communicates the hazard, which is why a walk-around includes checking they are legible and secure. Or substantial loss of effectiveness.

A placard may be made of any plastic, metal or other material capable of withstanding, without deterioration or a substantial reduction in effectiveness, a 30-day exposure to open weather conditions.

49 CFR 172.519

172.504(c)(2) exempts such a rail car, because placarding a carrier of unplacarded units would communicate a hazard that is not there.

The exception depends on nothing in the load itself requiring placarding.

A rail car loaded with transport vehicles or freight containers, none of which is required to be placarded.

49 CFR 172.504

172.504(d)(2) exempts them outright.

This is distinct from the residue rule in 172.504(d)(1), which affects only the weight calculation rather than exempting the vehicle.

Transport vehicles or freight containers used to transport empty IBCs in accordance with § 173.29(d) of this subchapter are not subject to placarding requirements of this part.

49 CFR 172.504

172.504(f)(4) drops the OXIDIZER placard where EXPLOSIVES 1.1 or 1.2 placards are displayed, since the explosive hazard dominates.

172.504(f)(5) gives a parallel rule for Division 1.5. The vehicle must be placarded EXPLOSIVES 1.1 or 1.2.

OXIDIZER placards are not required for Division 5.1 materials on freight containers, unit load devices, transport vehicles or rail cars which also contain Division 1.1 or 1.2 materials and which are placarded with EXPLOSIVES 1.1 or 1.2 placards, as required.

49 CFR 172.504

Check yourself

Answers are in the practice test for this topic.