25 realistic Hazardous Materials practice questions for District of Columbia CDL applicants. Required for: Drivers transporting placarded hazardous materials. Official test: 30 questions, 24 correct to pass.
Question 1 of 25 · HazMat Driving
When transporting Class 1 explosives, the driver must:
-
A.
Park anywhere convenient
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B.
Have a written route plan and follow it
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C.
Drive only at night
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D.
Drive only on local roads
Correct answer: B.
Drivers must have a route plan and avoid populated areas where possible.
Question 2 of 25 · Loading
What is "containment"?
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A.
Putting HazMat in proper packaging
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B.
A type of placard
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C.
Stopping leaks during transport
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D.
Containing fumes inside the trailer
Correct answer: A.
Containment means using packaging that meets DOT specifications for the material being shipped.
Question 3 of 25 · Placards
Green placards usually indicate:
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A.
Compressed gases (non-flammable)
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B.
Explosives
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C.
Poisons
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D.
Corrosives
Correct answer: A.
Green placards usually indicate non-flammable compressed gases.
Question 4 of 25 · Shipping Papers
Where can drivers find emergency contact information for the materials they're hauling?
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A.
On the placards
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B.
In the shipping papers
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C.
On the trailer doors
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D.
In the glove box
Correct answer: B.
A 24-hour emergency contact number must appear on the shipping papers.
Question 5 of 25 · HazMat Driving
What should a driver do before transporting any HazMat shipment?
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A.
Inspect the placards and shipping papers
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B.
Inspect the vehicle and cargo
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C.
Plan the route
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D.
All of the above
Correct answer: D.
Verify all paperwork, vehicle, cargo, and route before HazMat transport.
Question 6 of 25 · HazMat Driving
Drivers must avoid which of these areas when transporting HazMat?
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A.
Tunnels and bridges where prohibited
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B.
Heavily populated areas when alternative routes exist
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C.
Open flames or heat sources
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D.
All of the above
Correct answer: D.
Avoid restricted areas, populated zones, and any ignition sources.
Question 7 of 25 · Placards
Which of these placards has a yellow background?
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A.
Flammable solids
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B.
Oxidizers
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C.
Corrosives
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D.
Radioactive
Correct answer: B.
Yellow background placards typically indicate oxidizers.
Question 8 of 25 · HazMat Driving
What is the speed limit when transporting HazMat through a tunnel?
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A.
Tunnel speed limit minus 10 mph
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B.
Posted limit
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C.
No speed limit applies to HazMat
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D.
Posted speed unless lower limit is posted for HazMat
Correct answer: D.
Follow posted limits; lower limits often apply specifically to HazMat in tunnels.
Question 9 of 25 · Shipping Papers
What information must a HazMat driver have on the bills of lading?
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A.
Total quantity by weight or volume
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B.
Number and type of packages
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C.
Shipping name and hazard class
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D.
All of the above
Correct answer: D.
All of these must be included for HazMat shipments.
Question 10 of 25 · Parking
When parking HazMat overnight, you should:
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A.
Park near homes
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B.
Choose well-lit, safe areas away from people and buildings
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C.
Park on the shoulder of any road
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D.
Park in residential areas
Correct answer: B.
Use safe, well-lit parking areas away from people and buildings.
Question 11 of 25 · Rail Crossings
When approaching railroad crossings hauling HazMat, you should:
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A.
Stop within 15-50 feet of the nearest rail
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B.
Stop only at marked crossings
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C.
Slow down only
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D.
Speed up to clear quickly
Correct answer: A.
Stop 15 to 50 feet from nearest rail. Don't shift gears while crossing.
Question 12 of 25 · CDL Rules
What does the letter "H" represent on a CDL?
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A.
Hazardous materials endorsement
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B.
Heavy vehicle endorsement
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C.
Highway driving endorsement
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D.
Hauling endorsement
Correct answer: A.
The H endorsement allows a CDL holder to transport placarded hazardous materials.
Question 13 of 25 · HazMat Driving
When transporting HazMat over long distances, drivers should:
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A.
Stay alert, take rest breaks, and inspect the load regularly
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B.
Drive at maximum speed limit
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C.
Skip rest stops to save time
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D.
Avoid highways
Correct answer: A.
Stay alert with regular rest breaks; inspect cargo at every stop.
Question 14 of 25 · Hours of Service
Drivers transporting hazardous materials must keep a written record of duty status because:
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A.
It's a federal regulation for HazMat operations
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B.
Insurance requires it
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C.
It looks professional
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D.
Drivers don't need to keep records
Correct answer: A.
Federal hours-of-service rules apply to HazMat drivers as to other CMV drivers.
Question 15 of 25 · Loading
When loading or unloading HazMat:
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A.
Set the parking brake
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B.
Be sure the cargo is properly braced
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C.
Stay close to the vehicle
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D.
All of the above
Correct answer: D.
Keep the brakes set, secure cargo, and remain on alert during loading and unloading.
Question 16 of 25 · Shipping Papers
HazMat shipping papers must be:
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A.
Out of the driver's reach
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B.
Within the driver's reach while driving and clearly distinguished from other shipping papers
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C.
In the trailer with the cargo
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D.
Mailed to the receiver in advance
Correct answer: B.
Shipping papers must be within reach and identifiable. They must be on the seat or in a door pouch.
Question 17 of 25 · Placards
How many sides of a HazMat vehicle must be placarded?
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A.
One
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B.
Two
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C.
Three
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D.
Four
Correct answer: D.
Placards must be displayed on all four sides of the vehicle.
Question 18 of 25 · CDL Rules
Drivers transporting HazMat must have:
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A.
Only a regular driver license
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B.
A valid CDL with HazMat endorsement and TSA security threat assessment
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C.
A passport
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D.
Physician's certification only
Correct answer: B.
A current CDL with HazMat endorsement (and TSA background check) is required.
Question 19 of 25 · Placards
When must placards be displayed?
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A.
Before the vehicle is loaded
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B.
Once the HazMat is loaded and secured before driving
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C.
After the trip ends
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D.
Only at weigh stations
Correct answer: B.
Drivers must placard once HazMat is loaded and verify before moving the vehicle.
Question 20 of 25 · HazMat Basics
How many hazard classes are there?
Correct answer: C.
There are nine UN hazard classes used for HazMat transportation.
Question 21 of 25 · Emergencies
When a HazMat package leaks, you should:
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A.
Move it to a safe area
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B.
Secure the area and call for help
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C.
Continue the trip
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D.
Place it in the trailer's rear
Correct answer: B.
Don't move leaking packages. Secure the area and contact qualified responders.
Question 22 of 25 · Loading
You should turn off your engine when:
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A.
Loading or unloading flammable liquids
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B.
Driving on a hill
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C.
Inspecting brakes
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D.
Refueling on the highway
Correct answer: A.
Turn off the engine when loading or unloading flammable liquids to reduce ignition risk.
Question 23 of 25 · Placards
How are placards different from labels?
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A.
Labels go on packages; placards go on vehicles
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B.
Placards go on packages and labels go on vehicles
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C.
They are the same
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D.
Labels are only required outside the U.S.
Correct answer: A.
Labels mark individual packages; placards identify HazMat on vehicles.
Question 24 of 25 · HazMat Driving
When can drivers smoke around a HazMat vehicle?
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A.
While driving only
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B.
When parked at a truck stop
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C.
Never within 25 feet of certain materials
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D.
Whenever convenient
Correct answer: C.
Smoking is forbidden within 25 feet of HazMat including explosives, oxidizers, or flammables.
Question 25 of 25 · Shipping Papers
Which is true regarding HazMat shipping papers tabs?
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A.
They must be tabbed or be the first paper
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B.
They are filed alphabetically only
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C.
They are not required to be visible
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D.
They must be in a sealed envelope
Correct answer: A.
HazMat papers must be the top paper or tabbed to be readily identifiable.
About the Hazardous Materials Test
The Hazardous Materials (HazMat) test covers the rules for transporting materials that pose a risk to health, safety, and property. Topics include the hazardous materials table, shipping papers, marking, labeling, placarding, loading and unloading, bulk packaging, driving and parking rules, communications, emergencies, and hazardous materials regulations enforced by the U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration. A federal Transportation Security Administration (TSA) background check is also required.
The DC Department of Motor Vehicles administers this knowledge test as part of its commercial driver license program. To earn the HazMat Endorsement (H) on your District of Columbia CDL, you need to score at least 24 out of 30 on the official version.
Topics covered on this practice test
- HazMat Driving: 6 questions
- Placards: 5 questions
- Shipping Papers: 4 questions
- Loading: 3 questions
- CDL Rules: 2 questions
- Parking: 1 question
- Rail Crossings: 1 question
- Hours of Service: 1 question
- HazMat Basics: 1 question
- Emergencies: 1 question
How to use this practice test
- Read each question carefully. CDL questions are written precisely — small wording differences matter.
- Click "Show Answers & Explanations" only after answering every question. Don't peek mid-test.
- Read the explanation for every question, even ones you got right. The reasoning is more important than the answer.
- Repeat the test until you score 100%. The questions are deterministic per state, so you can track your improvement over multiple sessions.
- Move on to the other endorsement tests for District of Columbia until you're ready for the official exam.
Tips specific to the Hazardous Materials test
HazMat is the longest knowledge test (30 questions) and adds a Transportation Security Administration (TSA) background check. Most candidates struggle with placard colors, the segregation table, shipping paper requirements, and emergency response procedures. Use the official Emergency Response Guidebook (ERG) alongside this practice set.