CDL Hazmat Endorsement Practice Test 2026: Practice test 3

Practice test 3 of 4 for the CDL Hazmat Endorsement Practice Test: 25 more questions with answers and explanations.

Commercial vehicle
United States
90 questions
Checked October 10, 2026

Question 1 of 25
When loading or unloading explosives or flammable liquids, what should you do with the engine?
- Run it to keep the cab warm
- Leave it running at a high idle
- Turn it off unless it runs a pump
- Start it every few minutes
Show answer
Answer: C. Turn it off unless it runs a pump
Turn off the engine when loading or unloading explosives or flammable liquids, unless you need it to run a pump.
Question 2 of 25
What is the rule about cargo heaters when you carry explosives, flammable liquids or flammable gases?
- They are required in winter
- They are allowed if the load is small
- They are generally not allowed
- They must be on high
Show answer
Answer: C. They are generally not allowed
Cargo heaters are generally banned for explosives, flammable liquids and flammable gases.
Question 3 of 25
What kind of cargo space must you use for explosives, flammable solids and oxidizers?
- Any space, as long as the load is tied
- An open flatbed with the load hanging over
- A closed space, with no overhanging load
- The driver's cab, where you can watch it
Show answer
Answer: C. A closed space, with no overhanging load
These materials must be in a closed cargo space. Overhanging or tailgate loads are not allowed.
Question 4 of 25
What kind of floor lining is required when loading explosives?
- No lining is ever needed
- A wet rubber mat
- A steel plate
- A lining with no steel or iron
Show answer
Answer: D. A lining with no steel or iron
Floor linings for explosives must not contain steel or iron, which can make sparks.
Question 5 of 25
How must you handle explosives packages?
- Throw them gently onto the trailer
- Stack them as high as possible
- Never drop, throw or roll them
- Slide them on sharp edges
Show answer
Answer: C. Never drop, throw or roll them
Handle explosives carefully. Keep them away from sharp points and never drop, throw or roll them.
Question 6 of 25
Which combination may NOT carry Division 1.1 or 1.2 explosives?
- A van with closed doors
- A tractor with one semitrailer
- A triples combination
- A single straight truck
Show answer
Answer: C. A triples combination
Division 1.1 or 1.2 explosives may not be carried in a triples combination.
Question 7 of 25
For radioactive materials, what is the most total transport index allowed on one vehicle?
- 500
- 100
- 50
- 10
Show answer
Answer: C. 50
The total transport index of all radioactive packages on one vehicle must not be more than 50.
Question 8 of 25
Where must packages labeled POISON never be carried?
- In the cab or sleeper, or with food
- On a pallet with other freight
- In a closed, locked trailer
- At the front of the trailer
Show answer
Answer: A. In the cab or sleeper, or with food
Never carry poison packages in the cab or sleeper, or in the same vehicle with foodstuffs.
Question 9 of 25
Where may nitric acid be loaded?
- Anywhere in the trailer
- Not above any other product
- Only on top of other products
- Only in the cab
Show answer
Answer: B. Not above any other product
Never load nitric acid above any other product.
Question 10 of 25
Which materials may not be loaded or stored with acids?
- Paper
- Cyanides
- Cotton
- Sand
Show answer
Answer: B. Cyanides
Cyanides must not be loaded or stored with acids.
Question 11 of 25
How should you load glass carboys of corrosive liquid?
- Upright, one at a time
- On their sides, stacked high
- Several at once by dropping them in
- Upside down
Show answer
Answer: A. Upright, one at a time
Load corrosive carboys by hand, one by one, keeping them upright.
Question 12 of 25
A hazmat package is leaking at the dock. What should you do?
- Put it in the cab to watch it
- Load it at the back of the trailer
- Do not accept or transport it
- Tape it and drive
Show answer
Answer: C. Do not accept or transport it
Never transport leaking packages. Refuse them.
Question 13 of 25
On the segregation table, what does an X mean for two hazard classes?
- They may not be loaded together
- They may be loaded together
- They must ride in the cab
- They need extra placards
Show answer
Answer: A. They may not be loaded together
An X means the materials may not be loaded on the same vehicle. An O means they must be separated so they cannot mix.
Question 14 of 25
A placarded vehicle comes to a railroad crossing. Where must it stop?
- It does not need to stop at all
- 15 to 50 feet from the nearest rail
- Right at the edge of the first rail
- At least 100 feet from the tracks
Show answer
Answer: B. 15 to 50 feet from the nearest rail
Placarded vehicles and certain hazmat cargo tanks must stop within 50 feet of, and not closer than 15 feet to, the tracks.
Question 15 of 25
What must you never do while driving across railroad tracks with a hazmat load?
- Shift gears
- Look both ways
- Use a low gear
- Keep moving
Show answer
Answer: A. Shift gears
Do not shift gears while crossing the tracks.
Question 16 of 25
When must a vehicle with Division 1.1, 1.2 or 1.3 explosives be attended?
- Only when parked longer than one hour
- Only on public roads
- At all times
- Only at night
Show answer
Answer: C. At all times
A vehicle carrying these explosives must be attended at all times by the driver or another qualified person.
Question 17 of 25
Under the attendance rule, when is a hazmat vehicle attended?
- When the engine is running and the flashers are on, even if no one is near
- When you are awake in it (not in the sleeper) or within 100 feet with a clear view
- When the doors are locked and the alarm is set, even if you are inside a store
- When someone from the company is within 1 mile and can be reached by phone
Show answer
Answer: B. When you are awake in it (not in the sleeper) or within 100 feet with a clear view
Attended means you are awake in the vehicle and not in the sleeper berth, or within 100 feet with the vehicle in clear view.
Question 18 of 25
How close to the traveled part of a road may you park a vehicle with Division 1.1, 1.2 or 1.3 explosives?
- Right on the road edge
- No closer than 5 feet
- 10 feet only at night
- No closer than 1 mile
Show answer
Answer: B. No closer than 5 feet
Do not park explosives vehicles on or within 5 feet of the traveled part of a road.
Question 19 of 25
Except for brief stops, how far must a vehicle with Division 1.1, 1.2 or 1.3 explosives park from bridges, tunnels and buildings?
- At least 300 feet
- At least 100 feet
- At least 1,000 feet
- At least 25 feet
Show answer
Answer: A. At least 300 feet
These vehicles may not park within 300 feet of a bridge, tunnel, dwelling or place where people work or gather, except briefly.
Question 20 of 25
How close to an open fire may a placarded hazmat vehicle park?
- No closer than 25 feet
- There is no rule
- No closer than 50 feet
- No closer than 300 feet
Show answer
Answer: D. No closer than 300 feet
Do not park a hazmat vehicle within 300 feet of an open fire.
Question 21 of 25
While fueling a hazmat vehicle, what must happen?
- The driver waits inside the store
- Engine off, and someone at the nozzle
- Engine running, to keep power on
- The tank is filled right to the top
Show answer
Answer: B. Engine off, and someone at the nozzle
Turn off the engine, and a person must control the fueling at the point where the tank is filled.
Question 22 of 25
When must you check the tires on a hazmat vehicle?
- Only when a tire looks low or flat
- Only at the end of each trip
- At the start of each trip and each time you park
- Once a week, at the company yard
Show answer
Answer: C. At the start of each trip and each time you park
Inspect each tire at the beginning of each trip and each time the vehicle is parked.
Question 23 of 25
You find an overheated tire on a hazmat vehicle. What must you do?
- Let some air out and keep on driving
- Remove it and move it a safe distance away
- Drive faster so air flow cools it
- Spray it with water and keep driving
Show answer
Answer: B. Remove it and move it a safe distance away
An overheated tire must be removed right away and placed a safe distance away. Fix the cause before driving.
Question 24 of 25
A tire on your hazmat vehicle is flat. What may you do?
- Drive at normal speed until it overheats
- Let air out of the other tires
- Drive to your destination
- Drive only to the nearest safe place to fix it
Show answer
Answer: D. Drive only to the nearest safe place to fix it
A flat or leaking tire must be fixed before driving, but you may drive to the nearest safe place to repair it.
Question 25 of 25
What size fire extinguisher must a placarded vehicle carry?
- One rated 1 A or more
- One rated 2 B:C or more
- One rated 10 B:C or more
- Any size at all
Show answer
Answer: C. One rated 10 B:C or more
Power units of placarded vehicles must have a fire extinguisher rated 10 B:C or more.

Related tests