When may a DANGEROUS placard replace all separate Table 2 category placards on an otherwise qualifying mixed load?
Correct answer: For non-bulk packages needing different Table 2 placards, with no category at 2,205 lb or more loaded at one facility
DANGEROUS is optional for two or more non-bulk Table 2 categories requiring different placards. A category loaded at one facility at 1,000 kg (2,205 lb) or more must have its own placard. Bulk tanks do not qualify for this substitution.
Source: 49 CFR 172.504(b): DANGEROUS placard conditions ↗
Does the ordinary under-1,001-pound exception remove the placarding requirement for a material subject to the poison-inhalation-hazard placarding rule?
Correct answer: No; the required POISON INHALATION HAZARD or POISON GAS placard still applies
The weight exception does not apply to materials subject to 49 CFR 172.505. Use the appropriate required placard; the rules do not require duplicate poison-inhalation or poison-gas placards.
Source: 49 CFR 172.505(a), read with 172.504(c), (f)(8), (f)(11): Appropriate poison placard and no duplication ↗
With no applicable exception, must a bulk package containing only hazardous residue retain its required placards?
Correct answer: Yes
Residue is not automatically harmless or exempt. Keep the required placards unless cleaning, purging, or a specific regulatory exception permits their removal.
Source: 49 CFR 172.504(a), (d): Bulk residue and exceptions ↗
Which loading tool should not be used on HazMat packages?
Correct answer: A hook that could damage the container
Protect packaging from puncture or other damage during handling.
Source: Texas DL-7C, March 2026, section 9, PDF page 121: Loading tools ↗
How must hazardous-material packages be secured?
Correct answer: Brace them so they cannot fall, slide, or bounce
Movement can damage packages and fittings, so the load must be braced.
Source: Texas DL-7C, March 2026, section 9, PDF page 122: Securing cargo ↗
Which materials require special cargo-heater precautions and are normally kept out of a heated cargo space unless the rules are fully satisfied?
Correct answer: Explosives, flammable gas, and flammable liquids
Cargo heaters can create an ignition or heat hazard for Classes 1, 2.1, and 3.
Source: Texas DL-7C, March 2026, section 9, PDF page 122: Cargo heaters ↗
What floor-liner material is acceptable for Division 1.1, 1.2, or 1.3 explosives?
Correct answer: Nonmetallic material or nonferrous metal
The liner must be tight and must not contain iron or steel that can spark.
Source: Texas DL-7C, March 2026, section 9, PDF page 122: Explosive floor liner ↗
Which vertical loading rule applies to a package of nitric acid at 50% concentration or greater?
Correct answer: It must not be placed above a package of any other material
The federal loading rule prohibits placing nitric acid of at least 50% concentration above other materials. A leak could cause a dangerous reaction below.
Source: 49 CFR 177.839(a): Nitric acid concentration and placement ↗
What should cylinder supports prevent during transport of compressed gas?
Correct answer: Cylinders shifting or turning over
Use suitable racks, boxes or other compliant restraint for the cylinder design. Texas section 9.4.1 describes securing cylinders and keeping pressure-relief devices in the proper position. Follow the rules for the specific gas and cylinder.
Source: Texas DL-7C, March 2026, section 9, PDF page 123: Compressed gas cylinders ↗
May packages bearing or requiring POISON or POISON INHALATION HAZARD labels be carried with food or animal feed?
Correct answer: Only when the applicable packaging and segregation exception is fully satisfied
Do not treat ordinary separation as permission. The rule includes specified metal overpacks, separate closed unit-load devices, and a separate PG III condition. Poison-labeled packages are prohibited in the driver's compartment, including the sleeper.
Source: 49 CFR 177.841(e)(1)-(3): Food/poison exceptions and driver-compartment prohibition ↗
Under the handbook's general direct-attendance procedure, who must watch cargo-tank loading or unloading?
Correct answer: A qualified person must continuously attend the operation
The attendant must be alert, within 25 feet, able to see the tank, know the hazards and emergency procedures, and be authorized and able to move it. Specific regulatory attendance alternatives and exceptions require their own conditions.
Source: Texas DL-7C, March 2026, section 9, PDF page 124: Cargo tank watch ↗
Which distance from the traveled part of a public highway violates the parking rule for Division 1.1, 1.2, or 1.3 explosives?
Correct answer: 4 feet
Do not park on or within 5 feet of the traveled roadway. Being farther away does not by itself make parking lawful: separate rules cover property-owner consent and 300-foot separation from specified structures and gathering places.
Source: 49 CFR 397.7(a): Parking with explosives ↗
A cargo tank is transporting a flammable liquid. How far does the handbook’s no-smoking zone extend from the vehicle?
Correct answer: 25 feet
Smoking is prohibited on the vehicle and within 25 feet of it for this hazardous cargo.
Source: Texas DL-7C, March 2026, section 9, PDF page 126: No smoking ↗
How must a HazMat vehicle be refueled?
Correct answer: With the engine off and someone continuously controlling the nozzle
Continuous control and an off engine reduce ignition and spill risk.
Source: Texas DL-7C, March 2026, section 9, PDF page 126: Refueling ↗
What minimum extinguisher rating is required on a power unit transporting hazardous materials in a quantity requiring placarding?
Correct answer: 10 B:C
A power unit carrying a placard-required quantity needs a UL-rated extinguisher of at least 10 B:C. The rule is based on the required placarding, not merely a voluntarily displayed placard.
Source: 49 CFR 393.95(a)(1)(i): Placard-required hazardous-material quantity ↗
Under the hazardous-material driving rules, when must the driver examine each tire on a vehicle required to be marked or placarded?
Correct answer: At the start of every trip and each time the vehicle is parked
Check at trip start and whenever parked. Correct an unsafe tire condition before continuing, subject to the rule's limited allowance to reach the nearest safe repair place for a flat, leaking, or improperly inflated tire.
Source: 49 CFR 397.17(a)-(d), read with 397.1(a): Scope, examination, and tire-condition response ↗
At a railroad crossing with no legal stop exception, what must the driver of a placarded gasoline cargo tank do?
Correct answer: Stop 15 to 50 feet from the nearest rail, then look and listen before crossing
Stop at the required distance. Proceed only when no train is approaching and the entire vehicle can clear. Do not change gears on the tracks.
Source: Texas DL-7C, March 2026, section 9, PDF page 127: Railroad crossings ↗
What should a driver do when HazMat is leaking from the vehicle?
Correct answer: Park safely, secure the area, stay upwind, remain there, and call for help
Do not spread contamination, repack leaks, or use smell to identify material.
Source: Texas DL-7C, March 2026, section 9, PDF page 127: Leak response ↗
A HazMat trailer has hot doors and a suspected cargo fire. What should the driver do?
Correct answer: Keep the doors closed, move people away, and call for emergency help
Opening the doors can feed the fire and cause a flare-up. Do not approach or fight a hazardous cargo fire without the required training and equipment. Keep shipping information available for responders from a safe location.
Source: Texas DL-7C, March 2026, section 9, PDF page 127: Cargo fire ↗
A HazMat incident during transportation causes an injury requiring hospital admission. How soon must the NRC be notified?
Correct answer: As soon as practical, but no later than 12 hours after the incident
When the injury directly results from the hazardous material, call the NRC as soon as practical and within 12 hours. Do not delay beyond securing the scene safely. The written incident report is a separate requirement.
Source: 49 CFR 171.15(a), (b)(1)(ii): Immediate NRC notice ↗
