25 realistic Hazardous Materials practice questions for Maryland CDL applicants. Required for: Drivers transporting placarded hazardous materials. Official test: 30 questions, 24 correct to pass.
Question 1 of 25 · Emergencies
Which of these is the best advice if you have a HazMat leak?
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A.
Continue to the destination
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B.
Stop, secure the area, communicate the danger, get help
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C.
Try to repair it yourself
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D.
Cover the leak
Correct answer: B.
Stop, secure, communicate, and get qualified help. Don't try to handle leaks yourself.
Question 2 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 3 of 25 · Loading
What is "compatibility group letter"?
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A.
A code that tells which explosives can be loaded together
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B.
A type of placard
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C.
A type of vehicle
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D.
A type of safety vest
Correct answer: A.
Letters such as "A," "B," etc., classify explosives that can be transported together.
Question 4 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 5 of 25 · Loading
Which of these can never be hauled with explosives?
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A.
Cyanides or other toxic substances
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B.
Building materials
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C.
Foodstuffs
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D.
Newspapers
Correct answer: A.
Cyanides, certain other poisons, and other incompatible substances cannot be loaded with explosives.
Question 6 of 25 · Placards
What does "subsidiary hazard class" mean?
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A.
A secondary hazard a material poses
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B.
A backup placard
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C.
A small package
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D.
A vehicle accessory
Correct answer: A.
Some materials have a primary and a subsidiary hazard class for additional risks.
Question 7 of 25 · HazMat Basics
Which is the goal of HazMat regulations?
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A.
To make HazMat transport safer for everyone
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B.
To allow easy transport of HazMat
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C.
To increase shipping costs
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D.
To require more inspections
Correct answer: A.
HazMat rules contain risk to public safety, property, and the environment.
Question 8 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 9 of 25 · Emergencies
What is the first thing you should do if your HazMat load catches fire?
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A.
Pull over, away from buildings or vehicles, then call 911
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B.
Drive to the nearest hospital
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C.
Continue to destination
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D.
Try to put it out with snow
Correct answer: A.
Stop in a safe place, away from people and buildings, then notify emergency services.
Question 10 of 25 · Emergencies
When must drivers inform the carrier and emergency responders during a HazMat emergency?
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A.
As soon as it's safe to do so
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B.
When they reach the destination
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C.
Only after the cargo is unloaded
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D.
Only if asked
Correct answer: A.
Notify carrier and authorities immediately as soon as you can safely do so.
Question 11 of 25 · HazMat Driving
When transporting Class 1 explosives, the driver must:
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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 12 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 13 of 25 · Rail Crossings
What is the maximum stopping distance allowed for HazMat vehicles approaching a railroad crossing?
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A.
Stop within 15-50 feet of the nearest rail and not closer than 15 feet
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B.
Stop on the tracks
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C.
Stop only when train is approaching
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D.
No stop required
Correct answer: A.
HazMat vehicles must stop 15 to 50 feet from the nearest rail before crossing.
Question 14 of 25 · Placards
Yellow placards generally indicate:
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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 materials
Correct answer: B.
Yellow placards usually indicate oxidizers.
Question 15 of 25 · Security
Which of these is part of the carrier's security plan?
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A.
Personnel security
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B.
Unauthorized access prevention
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C.
En-route security
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D.
All of the above
Correct answer: D.
Carrier security plans cover personnel checks, access controls, and en-route security.
Question 16 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 17 of 25 · Shipping Papers
Where do you find a list of names of hazardous wastes?
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A.
EPA Hazardous Waste Manifest
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B.
Driver manual
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C.
Local newspaper
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D.
CDL handbook
Correct answer: A.
Hazardous waste appears on the EPA hazardous waste manifest, signed by both shipper and driver.
Question 18 of 25 · Emergency Equipment
Which type of fire is most likely to occur with HazMat?
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A.
Tire fires
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B.
Electrical fires
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C.
Engine compartment fires
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D.
All of the above
Correct answer: D.
Any of these can occur — pre-trip and en-route inspections reduce risk.
Question 19 of 25 · Loading
What does the term "marking" refer to?
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A.
Marking the shipper's name on the package
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B.
Putting the proper shipping name and ID number on the package
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C.
Marking the truck's plates
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D.
Marking the route on a map
Correct answer: B.
Marking includes the proper shipping name and the four-digit ID number on the package.
Question 20 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 21 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.
Question 22 of 25 · Emergencies
What does "ERG" stand for?
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A.
Emergency Response Guide
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B.
Energy Regulations Guide
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C.
Environmental Resource Guide
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D.
Emissions Reduction Guide
Correct answer: A.
The DOT Emergency Response Guidebook contains response info for HazMat incidents.
Question 23 of 25 · Security
Which is true about HazMat security?
-
A.
Drivers should keep doors locked when stopped
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B.
Drivers should never leave the vehicle unattended
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C.
Drivers must follow the carrier's security plan
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D.
All of the above
Correct answer: D.
All these practices reduce theft and tampering risk for HazMat.
Question 24 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 25 of 25 · Placards
Placards are warning signs placed on:
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A.
Drivers' shirts
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B.
The outside of vehicles transporting HazMat
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C.
The shipping papers only
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D.
Inside the cab
Correct answer: B.
Diamond-shaped placards on the four sides of the vehicle warn others of hazardous cargo.
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 Maryland Motor Vehicle Administration administers this knowledge test as part of its commercial driver license program. To earn the HazMat Endorsement (H) on your Maryland CDL, you need to score at least 24 out of 30 on the official version.
Topics covered on this practice test
- Placards: 5 questions
- Emergencies: 4 questions
- HazMat Driving: 4 questions
- Loading: 4 questions
- Security: 2 questions
- Shipping Papers: 2 questions
- HazMat Basics: 1 question
- CDL Rules: 1 question
- Rail Crossings: 1 question
- Emergency Equipment: 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 Maryland 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.