Practice questions written from the official CDL manual. Correct answers and explanations are shown below each question. (Turn on JavaScript for the interactive practice and exam-simulation modes.)
1. According to the CDL manual, what are the three main purposes of the hazardous materials regulations?
- AContain the material, communicate the risk, and ensure safe drivers and equipmentCorrect
- BCollect taxes, register shippers, and inspect warehouses
- CSpeed up delivery, lower shipping costs, and reduce paperwork
- DTrain firefighters, license chemists, and build safer roads
Why: The rules are built around three goals: contain the material so it does not leak or spill, communicate the risk so everyone knows the danger, and make sure drivers and equipment are safe to haul the load. Everything in the hazmat section supports one of these three ideas.
Based on: CDL Manual §9.1 — The Intent of the Regulations
2. In the hazardous materials rules, what does the goal to "contain the material" mainly deal with?
- AChoosing the fastest delivery route
- BPlacing placards on all four sides of the vehicle
- CMaking sure the driver holds a valid hazmat endorsement
- DProper packaging, loading, and handling so the material does not escapeCorrect
Why: "Contain the material" is about keeping the product safely inside its package. Rules on packaging, loading, and handling are written so the hazardous material does not leak, spill, or vent and hurt people or the environment.
Based on: CDL Manual §9.1 — Contain the Material
3. The rules "communicate the risk" of a hazardous load through all of the following EXCEPT:
- AShipping papers
- BLabels and package markings
- CPlacards on the vehicle
- DThe color of the truck's cabCorrect
Why: Risk is communicated using shipping papers, package markings and labels, and placards on the vehicle. These warnings begin with the shipper and follow the material to its destination. The color of the truck itself tells no one anything about the hazard.
Based on: CDL Manual §9.1 — Communicate the Risk
4. How many hazard classes are used to group hazardous materials in the regulations?
- AThree
- BSix
- CNineCorrect
- DTwelve
Why: There are nine hazard classes, numbered 1 through 9. Each class covers materials with a similar type of danger, such as explosives, gases, flammable liquids, or corrosives.
Based on: CDL Manual §9.1 — Hazard Classes
5. Which hazard class number is used for Explosives?
- AClass 1Correct
- BClass 3
- CClass 6
- DClass 8
Why: Class 1 is Explosives. Knowing the class numbers helps you read shipping papers and placards quickly. Class 3 is Flammable Liquids, Class 6 is Poisons, and Class 8 is Corrosives.
Based on: CDL Manual §9.1 — Hazard Classes
6. Materials such as gasoline and many fuels fall under which hazard class?
- AClass 2 (Gases)
- BClass 7 (Radioactive)
- CClass 3 (Flammable Liquids)Correct
- DClass 9 (Miscellaneous)
Why: Class 3 covers Flammable Liquids, which includes gasoline and many other fuels that can easily catch fire. Class 2 is Gases, Class 7 is Radioactive, and Class 9 is Miscellaneous hazardous materials.
Based on: CDL Manual §9.1 — Hazard Classes
7. Which hazard class covers Corrosive materials such as strong acids?
- AClass 4
- BClass 5
- CClass 7
- DClass 8Correct
Why: Class 8 is Corrosives, which includes materials like acids that can eat away at metal or skin. Class 4 is Flammable Solids, Class 5 is Oxidizers, and Class 7 is Radioactive materials.
Based on: CDL Manual §9.1 — Hazard Classes
8. Which hazard class is used for Radioactive materials?
- AClass 5
- BClass 6
- CClass 7Correct
- DClass 9
Why: Class 7 is Radioactive materials. These loads have special labels (such as Radioactive Yellow III) and extra handling rules. Class 5 is Oxidizers, Class 6 is Poisons, and Class 9 is Miscellaneous.
Based on: CDL Manual §9.1 — Hazard Classes
9. The proper shipping description on a shipping paper must list the items in what order?
- AIdentification number, packing group, then proper shipping name
- BProper shipping name, hazard class, then identification numberCorrect
- CHazard class, weight, then the shipper's phone number
- DPlacard color, ID number, then hazard class
Why: The basic description must be shown in this order: proper shipping name, hazard class, and identification number (with a UN or NA prefix). Listing it the same way every time helps drivers and emergency crews read it fast.
Based on: CDL Manual §9.3 — Item Description on the Shipping Paper
10. On a shipping paper that lists both hazardous and non-hazardous items, how must the hazardous materials be shown?
- AWritten in cursive so only inspectors can read them
- BPrinted only on the back of the last page
- CLeft off the paper to save space
- DListed first, or highlighted, or marked with an "X" so they stand outCorrect
Why: Hazardous items must be easy to spot. They can be listed first, printed in a contrasting color, or marked with an "X" in a special column so the driver and responders can find them right away among the other freight.
Based on: CDL Manual §9.3 — The Shipping Paper
11. While driving, where must a hazardous materials shipping paper be kept?
- AIn a pouch on the driver's door or in clear view within reach while the seat belt is fastenedCorrect
- BLocked in the trailer with the freight
- CMailed ahead to the delivery point
- DIn the sleeper berth under the mattress
Why: The paper must be within the driver's reach. It should be in a pouch on the driver's door or in clear view within reach while the seat belt is buckled, so it can be grabbed quickly if there is a crash or inspection.
Based on: CDL Manual §9.3 — Shipping Paper Accessibility
12. Where should the hazardous materials shipping paper be placed when the driver leaves the vehicle?
- AOn the driver's seat or in the driver's door pouchCorrect
- BIn the glove box, locked
- CTaped to the outside of the trailer
- DHanded to the nearest bystander
Why: When the driver is out of the truck, the shipping paper must be left in the driver's door pouch or in plain view on the driver's seat. This way emergency responders can find the information even if the driver is not there.
Based on: CDL Manual §9.3 — Shipping Paper Accessibility
13. For most Table 2 hazardous materials, a placard is required when the total amount in the vehicle reaches what weight?
- A100 pounds or more
- B500 pounds or more
- C1,001 pounds or moreCorrect
- D10,000 pounds or more
Why: For Table 2 materials, you must placard when the aggregate gross weight of the hazardous materials is 1,001 pounds or more. Below that amount, these materials generally do not require placards.
Based on: CDL Manual §9.3 — Placarding (Table 2)
14. How much of a Table 1 hazardous material must be aboard before the vehicle needs placards?
- AAny amount, no matter how smallCorrect
- BOnly 1,001 pounds or more
- COnly 5,000 pounds or more
- DOnly a full truckload
Why: Table 1 lists the most dangerous materials. Any amount of a Table 1 material requires placards, even a very small quantity. The 1,001-pound rule only applies to the less-hazardous Table 2 materials.
Based on: CDL Manual §9.3 — Placarding (Table 1)
15. Which of the following materials appears on Table 1, meaning it must be placarded in any amount?
- AA non-flammable compressed gas (Class 2.2)
- BA poison gas / toxic inhalation gas (Division 2.3)Correct
- CA corrosive liquid (Class 8) weighing 200 pounds
- DA miscellaneous material (Class 9)
Why: Table 1 includes the most dangerous materials, such as Division 2.3 poison (toxic) gas, certain explosives, materials that are dangerous when wet, poison-inhalation-hazard materials, and Radioactive Yellow III. These must be placarded even in tiny amounts. The others are Table 2 materials that need placards only at 1,001 pounds or more.
Based on: CDL Manual §9.3 — Placarding Tables
16. How many placards must a placarded vehicle display, and where?
- AOne placard on the rear only
- BTwo placards, one on each side
- CFour placards, one on each side and one on each endCorrect
- DSix placards spaced along each side
Why: A placarded load must show four placards: one on each side and one on each end of the vehicle. That way the warning can be seen from any direction the vehicle is approached.
Based on: CDL Manual §9.3 — Placarding
17. Which statement about placard placement on the vehicle is correct?
- APlacards may be partly hidden behind ladders or hoses if space is tight
- BPlacards should be laid flat on the floor of the trailer
- CEach placard must be readable from the direction it faces and kept clear of other markingsCorrect
- DOne placard on the driver's door is enough
Why: Placards must be turned so they read as a diamond (point up), be easily seen from the direction they face, and be kept away from ladders, pipes, doors, or other markings that could hide or confuse them. They must not be dirty or damaged.
Based on: CDL Manual §9.3 — Placarding
18. Who is responsible for making sure the vehicle is properly placarded before it is driven?
- AThe driverCorrect
- BThe state police
- CThe person who receives the load
- DNo one, placards are optional
Why: Placarding the vehicle is the driver's job. The shipper supplies the placards, but the driver must make sure the correct placards are in place before moving the truck. Driving a load that should be placarded without placards is illegal.
Based on: CDL Manual §9.3 — Placarding
19. What is the difference between a hazmat label and a hazmat placard?
- ALabels go on the vehicle; placards go on individual packages
- BLabels are small diamonds placed on packages; placards are larger diamonds placed on the vehicleCorrect
- CThey are the same thing with different names
- DLabels are required only at night; placards only in the daytime
Why: Labels are the smaller diamond-shaped warnings the shipper puts on each package. Placards are the larger diamond signs placed on the outside of the vehicle. Both use the same warning system, but at different sizes for packages versus the whole load.
Based on: CDL Manual §9.3 — Package Labels and Placards
20. In the Hazardous Materials Table, the proper shipping name of a material is found in which type of column?
- AIt is never listed and must be memorized
- BThe driver's home-state column
- CThe color-of-placard column only
- DA column that gives the proper shipping name for each materialCorrect
Why: The Hazardous Materials Table lists each regulated material by its proper shipping name, along with its hazard class, identification number, packing group, and required labels. Drivers and shippers use this table to describe the load correctly on the papers.
Based on: CDL Manual §9.3 — The Hazardous Materials Table
21. During loading or unloading of Class 1 (Explosives), Class 3 (Flammable Liquids), Class 4, Class 5, or Class 2.1 materials, how close may you smoke?
- AYou may smoke anywhere as long as you are careful
- BNo smoking within 25 feet of the vehicle or materialCorrect
- CNo smoking within 5 feet
- DSmoking is allowed inside the cab only
Why: When loading or unloading these fire-prone materials, never smoke or carry a lighted cigarette, cigar, or pipe within 25 feet. A single spark near flammable or explosive materials can cause a disaster.
Based on: CDL Manual §9.4 — Loading and Unloading
22. When loading or unloading a cargo tank, what "dual protection" step must the driver take before starting?
- ATurn off the headlights and radio
- BRemove the placards until finished
- CSet the parking brake and chock the wheels so the vehicle cannot moveCorrect
- DDisconnect the trailer from the tractor
Why: Before loading or unloading a cargo tank, apply the parking brake AND chock the wheels. Using both brakes and chocks gives dual protection so the vehicle cannot roll while the tank is open and product is flowing.
Based on: CDL Manual §9.4 — Cargo Tanks, Loading and Unloading
23. When loading packages of hazardous materials, what must the driver do to keep them safe in transit?
- AStack the heaviest boxes on top so they are easy to reach
- BBrace and secure the containers so they will not fall, slide, or shiftCorrect
- CLeave them loose so they can settle during the trip
- DLoad only leaking packages first
Why: Hazardous material packages must be braced and secured so they cannot fall, slide, or bounce around during the trip. A container that shifts or tips over can break open and spill. Drivers should also refuse leaking packages.
Based on: CDL Manual §9.4 — Loading and Unloading
24. A vehicle displaying hazmat placards approaches a railroad crossing. What must the driver do?
- ASpeed up to clear the tracks quickly
- BSlow down but never come to a full stop
- CCross only if a train is in sight
- DStop 15 to 50 feet before the nearest rail, look and listen, then cross without shifting gearsCorrect
Why: Placarded vehicles (and those hauling chlorine) must stop 15 to 50 feet before the nearest rail at a railroad crossing. Look and listen for a train, then cross without changing gears, so the truck does not stall on the tracks.
Based on: CDL Manual §9.6 — Railroad Crossings
25. Why should a driver avoid shifting gears while crossing railroad tracks with a placarded load?
- AIt saves fuel
- BSo the vehicle does not stall or get stuck on the tracksCorrect
- CIt is required only for empty trucks
- DTo keep the placards from falling off
Why: Shifting gears on the tracks risks the transmission slipping out of gear and the truck stalling in the path of a train. Cross in a gear low enough to make it all the way across without shifting.
Based on: CDL Manual §9.6 — Railroad Crossings
26. When a placarded vehicle is parked and must be attended, where must the attendant be?
- AAnywhere within one mile of the vehicle
- BWithin 100 feet of the vehicle, awake, and with a clear view of itCorrect
- CAsleep in the sleeper berth is acceptable
- DAt the delivery location waiting for the load
Why: The person attending a placarded vehicle must be within 100 feet, have an unobstructed view of it, be awake (not in the sleeper berth), and be able to move the vehicle if needed. This keeps someone ready to act if there is a problem.
Based on: CDL Manual §9.6 — Attending Parked Vehicles
27. How often must a driver hauling a placarded load check the vehicle's tires?
- AOnly once a month
- BAt the start of each trip and each time the vehicle is parkedCorrect
- COnly when a warning light comes on
- DOnly at the delivery point
Why: Drivers of placarded vehicles must examine each tire at the start of the trip and each time the vehicle is parked. An overheated tire must be removed and placed a safe distance from the vehicle, and you must not drive until the cause is fixed.
Based on: CDL Manual §9.6 — Tire Checks
28. What is the main purpose of the Emergency Response Guidebook (ERG)?
- ATo list the prices of hazardous chemicals
- BTo replace the shipping papers
- CTo record the driver's hours of service
- DTo help responders and drivers know what to do in a hazmat spill, leak, fire, or crashCorrect
Why: The Emergency Response Guidebook, published by the U.S. Department of Transportation, helps drivers and emergency crews quickly identify hazards and take the right first steps if a hazardous material spills, leaks, catches fire, or is involved in a crash.
Based on: CDL Manual §9.7 — Emergency Response Guidebook
29. Which of these situations requires immediate notice (a report) of a hazardous materials incident?
- AA person is killed, or an injury requires hospitalizationCorrect
- BThe driver takes a longer route than planned
- CThe load is delivered ten minutes late
- DA placard gets slightly dusty
Why: Immediate notice must be given when a hazmat incident causes a death, an injury needing hospitalization, property damage over $50,000, an evacuation, the closing of a major roadway, or certain other serious events. These reports get the right help and warnings moving fast.
Based on: CDL Manual §9.7 — Incident Reporting
30. When practical, a driver hauling a placarded load should do which of the following?
- AAlways choose the busiest downtown streets
- BIgnore local hazmat route rules
- CAvoid heavily populated areas, tunnels, and narrow streets when a safe route allowsCorrect
- DPark next to open flames to stay warm
Why: Drivers should avoid heavily populated areas, tunnels, narrow streets, and crowds when a practical safe route is available, and must obey local hazmat route restrictions and permit rules. This limits the danger to the public if something goes wrong.
Based on: CDL Manual §9.6 — Routes and Restrictions