CDL Hazmat placarding practice questions
20 free practice questions from 49 CFR Part 172 Subpart F. Each answer is explained and linked to the rule it comes from.
CDL Hazmat placarding
20 questions across 8 topics. After each answer you see why it is right, with a link to the official source.
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Who the placarding rules cover
1. A delivery van carries only packages of Division 6.2 infectious substances and no other hazardous material. How does 172.500(b) treat placarding for this load?
- A. Placards are needed once the packages reach 454 kg (1,001 pounds) aggregate gross weight
- B. A DANGEROUS placard is needed on each side and each end
- C. The placarding subpart does not apply to infectious substances
- D. Placards are needed on two opposite sides only
Show answer
Answer: C. The placarding subpart does not apply to infectious substances
172.500(b) states that "This subpart does not apply to— (1) Infectious substances;". Table 2 of 172.504(e) likewise lists "6.2 NONE" as the placard for that division.
Source: eCFR: 49 CFR 172.500, Applicability of placarding requirements (as of Nov 4, 2026)
2. Under 172.500(b)(2), which condition takes hazardous materials authorized to be offered as a limited quantity outside the placarding subpart?
- A. When identified as such on a shipping paper in accordance with 172.203(b) or when marked as such in accordance with 172.315
- B. Only when the vehicle carries less than 454 kg (1,001 pounds) of them
- C. Only when they move by rail
- D. Only when the carrier's vehicle is already placarded
Show answer
Answer: A. When identified as such on a shipping paper in accordance with 172.203(b) or when marked as such in accordance with 172.315
The subpart does not apply to limited quantity materials "when identified as such on a shipping paper in accordance with § 172.203(b) or when marked as such in accordance with § 172.315."
Source: eCFR: 49 CFR 172.500, Applicability of placarding requirements (as of Nov 4, 2026)
Providing and affixing placards
3. Under 172.506(a), in which situation does the person offering a hazardous material to a motor carrier by highway not have to provide the required placards?
- A. When the driver holds a hazardous materials endorsement
- B. When the material is loaded at the carrier's own terminal
- C. When the shipment goes to a single consignee
- D. When the carrier's motor vehicle is already placarded for the material as required by the subpart
Show answer
Answer: D. When the carrier's motor vehicle is already placarded for the material as required by the subpart
The offeror "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, unless the carrier's motor vehicle is already placarded for the material as required by this subpart."
Source: eCFR: 49 CFR 172.506, Providing and affixing placards: Highway (as of Nov 4, 2026)
4. Under 172.507(b), where may a nurse tank meeting 173.315(m) go without a placard?
- A. On any side facing the road shoulder
- B. On an end containing valves, fittings, regulators or gauges, when those appurtenances prevent the markings and placard from being properly placed and visible
- C. On every side, while the tank is on a farm
- D. On the top, when a placard holder is used
Show answer
Answer: B. On an end containing valves, fittings, regulators or gauges, when those appurtenances prevent the markings and placard from being properly placed and visible
A nurse tank "is not required to be placarded on an end containing valves, fittings, regulators or gauges when those appurtenances prevent the markings and placard from being properly placed and visible."
Source: eCFR: 49 CFR 172.507, Special placarding provisions: Highway (as of Nov 4, 2026)
5. Hazardous materials are offered for transportation not involving air transportation in a freight container with a capacity of less than 640 cubic feet, and the container is not placarded. What does 172.512(b)(2) require?
- A. The freight container must display one DANGEROUS placard on each end
- B. The freight container must be labeled in accordance with Subpart E
- C. The freight container must carry a copy of the shipping paper on its door
- D. The freight container must be marked "HOT"
Show answer
Answer: B. The freight container must be labeled in accordance with Subpart E
Such a freight container "need not be placarded. However, if not placarded, it must be labeled in accordance with subpart E of this part."
Source: eCFR: 49 CFR 172.512, Freight containers and aircraft unit load devices (as of Nov 4, 2026)
Prohibited and permissive placarding
6. Which kind of display on a motor vehicle does 172.502(a)(2) prohibit?
- A. Any sign that shows the motor carrier's name
- B. Any advertisement placed more than 3 inches from a placard
- C. Any slogan written in a language other than English
- D. A sign, advertisement, slogan or device that, by its color, design, shape or content, could be confused with a placard prescribed in the subpart
Show answer
Answer: D. A sign, advertisement, slogan or device that, by its color, design, shape or content, could be confused with a placard prescribed in the subpart
No person may display "Any sign, advertisement, slogan (such as “Drive Safely”), or device that, by its color, design, shape or content, could be confused with any placard prescribed in this subpart."
Source: eCFR: 49 CFR 172.502, Prohibited and permissive placarding (as of Nov 4, 2026)
General requirements and the placard tables
7. Which Division 6.1 material is listed in Table 1 of 172.504(e)?
- A. Material poisonous by inhalation
- B. Packing Group III material
- C. Material in non-bulk packagings
- D. Material other than material poisonous by inhalation
Show answer
Answer: A. Material poisonous by inhalation
Table 1 lists "6.1 (material poisonous by inhalation (see § 171.8 of this subchapter))", while Table 2 lists "6.1 (other than material poisonous by inhalation)".
Source: eCFR: 49 CFR 172.504, General placarding requirements (as of Nov 4, 2026)
8. Besides packages bearing the Radioactive Yellow III label, which shipment does the footnote to the Class 7 row of Table 1 in 172.504(e) say also requires RADIOACTIVE placards?
- A. Every Class 7 package carried by a private carrier
- B. Every Class 7 package loaded together with Class 9 material
- C. All shipments of unpackaged LSA-I material or SCO-I
- D. Every Class 7 package loaded at a carrier's terminal
Show answer
Answer: C. All shipments of unpackaged LSA-I material or SCO-I
The footnote reads: "RADIOACTIVE placards are also required for: All shipments of unpackaged LSA-I material or SCO-I;" along with certain exclusive use shipments and closed vehicles used under 173.443(d).
Source: eCFR: 49 CFR 172.504, General placarding requirements (as of Nov 4, 2026)
The 454 kg exception and empty packages
9. Besides hazardous materials subject to 172.505, what does 172.504(c) leave outside its exception for less than 454 kg (1,001 pounds) of Table 2 materials?
- A. Non-bulk packages of Class 3 materials
- B. Bulk packagings
- C. Freight containers moved by highway
- D. Shipments moved by rail
Show answer
Answer: B. Bulk packagings
172.504(c) begins "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—".
Source: eCFR: 49 CFR 172.504, General placarding requirements (as of Nov 4, 2026)
10. When working out placarding requirements, how does 172.504(d)(1) treat a non-bulk packaging that contains only the residue of a Table 2 material not subject to 172.505?
- A. It counts at its full marked capacity
- B. It counts as 454 kg (1,001 pounds) on its own
- C. It must be placarded on two opposite sides
- D. It need not be included in determining placarding requirements
Show answer
Answer: D. It need not be included in determining placarding requirements
"Except for hazardous materials subject to § 172.505, 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."
Source: eCFR: 49 CFR 172.504, General placarding requirements (as of Nov 4, 2026)
DANGEROUS placard and other substitutions
11. A transport vehicle carries Division 1.1 and Division 1.3 explosives, so placards for both divisions would be required. Under 172.504(f)(1), which placard must be displayed?
- A. Both the EXPLOSIVES 1.1 and the EXPLOSIVES 1.3 placards
- B. A DANGEROUS placard in place of both explosives placards
- C. Only the placard representing the lowest division number, EXPLOSIVES 1.1
- D. Only the placard representing the highest division number, EXPLOSIVES 1.3
Show answer
Answer: C. Only the placard representing the lowest division number, EXPLOSIVES 1.1
172.504(f)(1) states: "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." The DANGEROUS placard in 172.504(b) is only for materials that "require different placards specified in table 2".
Source: eCFR: 49 CFR 172.504, General placarding requirements (as of Nov 4, 2026)
12. Which transport vehicle may omit OXIDIZER placards for the Division 5.1 materials it carries under 172.504(f)(4)?
- A. One that also contains Division 1.2 materials and is placarded with EXPLOSIVES 1.2 placards, as required
- B. One that also contains Class 3 materials and is placarded FLAMMABLE
- C. One that also contains Division 1.4 materials and is placarded EXPLOSIVES 1.4
- D. One that also contains Class 8 materials and is placarded CORROSIVE
Show answer
Answer: A. One that also contains Division 1.2 materials and is placarded with EXPLOSIVES 1.2 placards, as required
"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."
Source: eCFR: 49 CFR 172.504, General placarding requirements (as of Nov 4, 2026)
13. A transport vehicle carries a non-flammable gas together with a flammable gas and is placarded FLAMMABLE GAS as required. What does 172.504(f)(3) say about the NON-FLAMMABLE GAS placard?
- A. It must also be displayed on each side and each end
- B. It is not required
- C. It must replace the FLAMMABLE GAS placard on the front
- D. It must be displayed on the rear only
Show answer
Answer: B. It is not required
"A NON-FLAMMABLE GAS placard is not required on a transport vehicle which contains nonflammable gas if the transport vehicle also contains flammable gas or oxygen and it is placarded with FLAMMABLE GAS or OXYGEN placards, as required."
Source: eCFR: 49 CFR 172.504, General placarding requirements (as of Nov 4, 2026)
14. For domestic transportation, a CLASS 9 placard is not required. What does 172.504(f)(9) still require for a bulk packaging of a Class 9 material?
- A. It must display a DANGEROUS placard on each end
- B. It must display CLASS 9 placards on each side and each end
- C. It must carry a POISON placard on two opposite sides
- D. It must be marked with the appropriate identification number on a CLASS 9 placard, an orange panel, or a white square-on-point display configuration
Show answer
Answer: D. It must be marked with the appropriate identification number on a CLASS 9 placard, an orange panel, or a white square-on-point display configuration
"However, a bulk packaging must be marked with the appropriate identification number on a CLASS 9 placard, an orange panel, or a white square-on-point display configuration as required by subpart D of this part."
Source: eCFR: 49 CFR 172.504, General placarding requirements (as of Nov 4, 2026)
Subsidiary hazards and bulk packagings
15. A transport vehicle contains a material with a subsidiary hazard of being dangerous when wet, as defined in 173.124. What does 172.505(c) require?
- A. DANGEROUS WHEN WET placards on each side and each end, in addition to the placards required by 172.504
- B. DANGEROUS WHEN WET placards only when 454 kg (1,001 pounds) or more is loaded
- C. DANGEROUS WHEN WET placards in place of the placards required by 172.504
- D. Labels on the packages only, with no subsidiary placard
Show answer
Answer: A. DANGEROUS WHEN WET placards on each side and each end, in addition to the placards required by 172.504
Such a vehicle "shall be placarded with DANGEROUS WHEN WET placards, on each side and each end, in addition to the placards required by § 172.504."
Source: eCFR: 49 CFR 172.505, Placarding for subsidiary hazards (as of Nov 4, 2026)
16. A bulk packaging that had to be placarded while it held a hazardous material is now empty. Which condition in 172.514(b) allows it to no longer be placarded?
- A. It holds less than 454 kg (1,001 pounds) of residue
- B. It has been unloaded for more than 24 hours
- C. It is sufficiently cleaned of residue and purged of vapors to remove any potential hazard
- D. The driver carries the shipping paper from the last load
Show answer
Answer: C. It is sufficiently cleaned of residue and purged of vapors to remove any potential hazard
It "must remain placarded when it is emptied, unless it— (1) Is sufficiently cleaned of residue and purged of vapors to remove any potential hazard;" (or meets one of the other listed conditions).
Source: eCFR: 49 CFR 172.514, Bulk packagings (as of Nov 4, 2026)
17. Under 172.514(c)(1), how may a portable tank having a capacity of less than 3,785 L (1,000 gallons) be placarded?
- A. It needs neither placards nor labels
- B. Only with a DANGEROUS placard
- C. On the front end only
- D. On only two opposite sides or, alternatively, labeled instead of placarded in accordance with Subpart E
Show answer
Answer: D. On only two opposite sides or, alternatively, labeled instead of placarded in accordance with Subpart E
"The following packagings may be placarded on only two opposite sides or, alternatively, may be labeled instead of placarded in accordance with subpart E of this part: (1) A portable tank having a capacity of less than 3,785 L (1,000 gallons)."
Source: eCFR: 49 CFR 172.514, Bulk packagings (as of Nov 4, 2026)
Visibility, display and placard specifications
18. Under 172.516(b), where may the required placarding of the front of a motor vehicle be displayed?
- A. Only on the front of the cargo body
- B. On the front of the truck-tractor, instead of or in addition to the front of the cargo body
- C. Inside the windshield
- D. On the roof of the cab
Show answer
Answer: B. On the front of the truck-tractor, instead of or in addition to the front of the cargo body
"The required placarding of the front of a motor vehicle may be on the front of a truck-tractor instead of or in addition to the placarding on the front of the cargo body to which a truck-tractor is attached."
Source: eCFR: 49 CFR 172.516, Visibility and display of placards (as of Nov 4, 2026)
19. Under 172.516(c)(6), who must maintain a placard so that its format, legibility, color and visibility are not substantially reduced by damage, deterioration or dirt?
- A. The carrier
- B. The consignee
- C. The placard manufacturer
- D. The State that issued the driver's CDL
Show answer
Answer: A. The carrier
Each placard must "Be maintained by the carrier in a condition so that the format, legibility, color, and visibility of the placard will not be substantially reduced due to damage, deterioration, or obscurement by dirt or other matter;".
Source: eCFR: 49 CFR 172.516, Visibility and display of placards (as of Nov 4, 2026)
20. Under 172.542(c), on which placard may the word "GASOLINE" be used in place of the word "FLAMMABLE"?
- A. A placard on any transport vehicle carrying non-bulk gasoline cans
- B. A placard on a rail tank car only
- C. A placard displayed on a cargo tank or a portable tank being used to transport gasoline by highway
- D. A placard on any vehicle carrying Class 3 material
Show answer
Answer: C. A placard displayed on a cargo tank or a portable tank being used to transport gasoline by highway
"The word “GASOLINE” may be used in place of the word “FLAMMABLE” on a placard that is displayed on a cargo tank or a portable tank being used to transport gasoline by highway."
Source: eCFR: 49 CFR 172.542, FLAMMABLE placard (as of Nov 4, 2026)