25 realistic Hazardous Materials practice questions for Colorado CDL applicants. Required for: Drivers transporting placarded hazardous materials. Official test: 30 questions, 24 correct to pass.
Question 1 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 2 of 25 · Shipping Papers
Where can a driver find information about which HazMat are flammable?
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A.
Hazardous Materials Table
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B.
CDL test only
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C.
Engine manual
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D.
Driver license documents
Correct answer: A.
The DOT Hazardous Materials Table classifies materials and lists handling requirements.
Question 3 of 25 · HazMat Driving
Which is true about smoking near HazMat vehicles?
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A.
Smoking is fine while driving
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B.
Smoking is prohibited within 25 feet of certain materials
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C.
Smoking is allowed at truck stops
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D.
Smoking is allowed in residential areas
Correct answer: B.
Smoking is forbidden within 25 feet of explosives, oxidizers, and flammables.
Question 4 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 5 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 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 · 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 8 of 25 · Loading
Which of the following must NEVER be transported with a HazMat shipment?
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A.
Routine cargo
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B.
Other foods
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C.
Class A or B explosives without segregation tables
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D.
Pet food
Correct answer: C.
Explosives have strict segregation rules. Always consult the segregation table.
Question 9 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 10 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 11 of 25 · Tank Operations
Which of these are dangers of hauling liquids in tanks?
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A.
Liquid surge
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B.
Outage requirements
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C.
Top-heavy load
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D.
All of the above
Correct answer: D.
Surge, outage, and high center of gravity all make tank vehicles uniquely dangerous.
Question 12 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 13 of 25 · Inspection
HazMat drivers must inspect tires:
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A.
Once a day
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B.
At the start of the trip and at every stop
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C.
Once a week
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D.
Only at weigh stations
Correct answer: B.
Inspect tires before the trip and at each stop because hot or damaged tires raise fire risk.
Question 14 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 15 of 25 · HazMat Basics
Which HazMat is most dangerous if released into the environment?
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A.
Class 7 radioactive
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B.
Class 4 flammable solid
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C.
All HazMat are dangerous and require precaution
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D.
Class 9 miscellaneous
Correct answer: C.
Treat every HazMat shipment as dangerous and follow all rules.
Question 16 of 25 · HazMat Basics
How many hazard classes are there?
Correct answer: C.
There are nine UN hazard classes used for HazMat transportation.
Question 17 of 25 · Placards
Which placard color usually means a flammable material?
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A.
Red
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B.
Yellow
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C.
Green
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D.
Blue
Correct answer: A.
Red typically indicates flammable materials.
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 · Parking
When is parking allowed for HazMat vehicles?
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A.
On highway shoulders for any reason
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B.
In safe locations away from open flames, heat sources, and people
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C.
Anywhere is fine
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D.
Only at truck stops
Correct answer: B.
Park away from people, fires, ignition sources, and within sight when possible.
Question 20 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 21 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 22 of 25 · Shipping Papers
Which of these documents must accompany the HazMat?
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A.
Shipping papers
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B.
Hazard placards
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C.
Emergency response info
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D.
All of the above
Correct answer: D.
Shipping papers, placards, and emergency info must all accompany the load.
Question 23 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 24 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 25 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.
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 Colorado Division of Motor Vehicles administers this knowledge test as part of its commercial driver license program. To earn the HazMat Endorsement (H) on your Colorado CDL, you need to score at least 24 out of 30 on the official version.
Topics covered on this practice test
- HazMat Driving: 5 questions
- Loading: 4 questions
- Placards: 3 questions
- Emergencies: 2 questions
- Shipping Papers: 2 questions
- Rail Crossings: 2 questions
- HazMat Basics: 2 questions
- Tank Operations: 1 question
- Inspection: 1 question
- CDL Rules: 1 question
- Parking: 1 question
- Security: 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 Colorado 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.