A tool could damage a hazardous package's closure during unloading. Should it be used?
Correct answer: No; use handling equipment that will not damage containment.
Tools likely to impair a package or its closure must not be used. The restriction concerns damaging tools, not a blanket ban on handling equipment.
Source: 49 CFR 177.834(f). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
A cargo-tank unloading operation uses the ordinary in-person attendance method, with no special exception or alternative system. How close must the qualified person remain?
Correct answer: Within 25 feet of the cargo tank.
The ordinary method requires the qualified person within 25 feet, alert, and with the prescribed unobstructed view to the maximum extent practicable. Authorized alternative methods and product-specific exceptions have their own conditions.
Source: 49 CFR 177.834(i)(3)(i). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
For ordinary in-person cargo-tank attendance, which person is qualified?
Correct answer: One trained for the hazards and emergencies and able and authorized to move it.
The attendant must know the material's hazards and emergency procedures and have authority and means to move the tank under this attendance method.
Source: 49 CFR 177.834(i)(4). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
An approved remote cargo-tank monitoring system loses its monitoring capability during transfer. What must happen?
Correct answer: Terminate transfer immediately and restore compliant attendance.
The remote-system alternative requires immediate termination on loss of monitoring capability. A qualified person must immediately resume the required in-person attendance after remote-system failure.
Source: 49 CFR 177.834(i)(3)(ii)(C), (E). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
A placarded vehicle requires attendance. The attendant is outside, 80 feet away, but a building blocks the view. Does this meet the attendance definition?
Correct answer: No; the vehicle must be in unobstructed view.
An outside attendant must be within 100 feet and have an unobstructed view. On the vehicle, the attendant must be awake and not in a sleeper berth.
Source: 49 CFR 397.5(d)(1). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
A placarded vehicle needs an attendant. Does a driver asleep in the sleeper berth satisfy the rule?
Correct answer: No; the on-vehicle attendant must be awake and outside the sleeper berth.
The attendance definition specifically excludes sleeping and the sleeper berth. Its alternative outside position requires distance and unobstructed-view conditions.
Source: 49 CFR 397.5(d)(1). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
What makes a parking area a safe haven for unattended Division 1.1, 1.2 or 1.3 loads?
Correct answer: Specific written approval by a local, state or federal authority.
Safe haven is a defined approval status, not a driver's description of a convenient place. The other applicable attendance conditions still matter.
Source: 49 CFR 397.5(b), (d)(3). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
A truck containing Division 1.2 material is parked four feet from the traveled part of a public highway. Is this allowed under the parking rule?
Correct answer: No; it cannot be parked on or within five feet.
172.504 identifies this hazard for placarding, and 397.7(a)(1) forbids parking on or within five feet of the traveled portion of a public street or highway.
Source: 49 CFR 397.7(a)(1). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
A driver of a placarded Class 3 vehicle wants to park within five feet of the traveled roadway for personal shopping. Does the brief operational-necessity exception cover that stop?
Correct answer: No; personal shopping is not the stated operational necessity.
The exception requires a brief operational necessity and impracticability of parking elsewhere. It does not provide a general convenience-parking exemption.
Source: 49 CFR 397.7(b). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
A Division 1.1 vehicle is to be parked 200 feet from a dwelling, with no qualifying operational necessity. Is that within the prohibited zone?
Correct answer: Yes; the rule uses 300 feet in these circumstances.
The rule restricts parking within 300 feet of bridges, tunnels, dwellings and places where people work or assemble, with a narrowly stated brief operational exception.
Source: 49 CFR 397.7(a)(3). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
Before parking a Division 1.3 vehicle on private property, what must the person in charge of that property know and provide?
Correct answer: Awareness of the hazardous contents and consent to park.
Knowledge and consent must come from the person in charge of the property, who must be aware of the nature of the hazardous materials.
Source: 49 CFR 397.7(a)(2). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
How close may a vehicle carrying covered hazardous materials be parked to an open fire under 397.11?
Correct answer: It must not be parked within 300 feet.
The parking restriction is 300 feet. Passing an open fire is a separate issue requiring precautions to establish that the vehicle can safely pass without stopping.
Source: 49 CFR 397.11(a)–(b). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
A placarded truck contains Class 3 flammable liquid. Someone stands 15 feet away with a lit cigarette. Is that far enough under the smoking rule?
Correct answer: No; the prohibited area extends to 25 feet.
397.13 prohibits smoking or carrying lit cigarettes, cigars or pipes on or within 25 feet of the listed hazardous-material vehicles.
Source: 49 CFR 397.13(a). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
An empty tank vehicle previously carried placard-required Class 3 flammable liquid. Does emptying the liquid by itself remove the 25-foot smoking restriction?
Correct answer: No; the rule also covers this empty tank vehicle.
The rule expressly covers an empty tank motor vehicle used for the specified flammable liquid or gas service when marking or placarding was required.
Source: 49 CFR 397.13(b). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
A normal truck power unit carries hazardous materials in a quantity requiring placards. What is its minimum required extinguisher rating?
Correct answer: One extinguisher rated at least 10 B:C.
The placard-required power-unit minimum is 10 B:C. The extinguisher must also be accessible, charged and securely mounted; a rating does not authorize untrained cargo-fire response.
Source: 49 CFR 393.95(a)(1)(i), (a)(2)–(4). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
An empty cargo tank used for Class 3 flammable-liquid transportation breaks down. Which warning equipment is appropriate to carry?
Correct answer: Required reflective triangles, without flame-producing signals.
Flame-producing signals must not be carried on the specified cargo tank whether loaded or empty. The required reflective triangles provide a non-flame warning option.
Source: 49 CFR 393.95(f)(1), (g). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
When does the tire rule for covered hazardous-material vehicles require examination of each tire?
Correct answer: At the start of each trip and each time the vehicle is parked.
397.17(a) specifies trip-start and each-parking examinations. It does not replace the driver's other inspection duties.
Source: 49 CFR 397.17(a). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
A covered hazmat truck has a flat tire. Where may it be driven under the repair-location exception?
Correct answer: To the nearest safe place for the necessary repair.
The tire must be repaired, replaced or properly inflated before driving, except travel to the nearest safe place to perform that work. Other safe-operation requirements still apply.
Source: 49 CFR 397.17(b). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
A tire on a covered hazmat vehicle is found overheated. What must be resolved before further operation?
Correct answer: The cause of the overheating must be corrected.
The driver must cause the overheated tire to be removed to a safe distance and correct the cause before operating again. Arrange qualified help and maintain applicable parking and attendance precautions.
Source: 49 CFR 397.17(c)–(d). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
A Class 3 placard-required truck approaches an ordinary railroad grade crossing with no applicable exception. Where must it stop?
Correct answer: Between 15 and 50 feet from the tracks.
For a covered vehicle, stop within 50 feet but not closer than 15, then look and listen. Use a gear that allows crossing without shifting.
Source: 49 CFR 392.10(a), (a)(3)(vi). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
