Tennessee Hazmat CDL Practice Test

This is a free 20-question practice test for the Hazmat portion of the Tennessee Commercial Driver's License knowledge exam. Questions are pulled from a pool of 68 drawn from the AAMVA CDL Manual, which is the source document the Tennessee Department of Safety and Homeland Security Driver Services uses to write its actual exam.

How it works: Click an answer. The correct choice highlights in green, and you'll see a short explanation. Aim for 85% or better before you sit for the real test in Tennessee.

Question 1 of 20

Hazard Class 3 is:

Flammable liquids
Explosives
Toxic substances
Radioactive

Correct. Class 3 is flammable liquids — gasoline, diesel, ethanol, alcohols, etc.

Question 2 of 20

When parking a placarded hazmat vehicle at a truck stop overnight, you should:

Park in a designated hazmat parking area, follow attendance rules for explosives, never block traffic
Park behind the fuel pumps
Park in the entrance
Park anywhere

Correct. Use designated hazmat parking. Explosives and certain other materials require attended parking; review the carrier's policy and federal rules.

Question 3 of 20

When in the cab with the engine running, the hazmat shipping paper must be:

In the trailer
Within the driver's reach — clipped on the driver's door clip or on the driver's seat
In the glove compartment
In the trunk

Correct. When in the seat with the engine running, keep shipping papers within reach (driver-side door clip or on the seat). When out of the vehicle, leave on the seat or in the door pouch.

Question 4 of 20

A driver is required to carry an ERG (or equivalent) when:

Driving any commercial vehicle
Transporting any quantity of hazardous materials
Only when hauling explosives
Only on weekends

Correct. Whenever hazmat is being transported, the driver must have access to current ERG information for the materials in question.

Question 5 of 20

When you transport Division 1.1 or 1.2 explosives, you must have a written route plan:

No, never
Yes — required for these explosives
Only on weekends
Only across state lines

Correct. A written route plan is required for transporting Division 1.1 or 1.2 explosives. The driver must follow it unless there is an emergency.

Question 6 of 20

When you stop at a railroad crossing in a placarded hazmat vehicle, you must stop:

On the tracks
Between 15 and 50 feet from the nearest rail
Anywhere
Only if a train is visible

Correct. Placarded hazmat vehicles must stop at every railroad crossing 15 to 50 feet from the nearest rail. Look and listen for trains.

Question 7 of 20

Hazardous materials are products that:

Are heavier than normal cargo
Pose a risk to health, safety, or property during transportation
Can only be hauled at night
Require a special trailer color

Correct. Hazardous materials (hazmat) are products that pose a risk to health, safety, or property during transportation. Hazmat regulations are codified in 49 CFR.

Question 8 of 20

The four-digit ID number on a placard or shipping paper is the:

UN/NA identification number for the material
The driver's permit number
The truck VIN
The DOT registration number

Correct. The four-digit number is the UN/NA ID — used with the ERG to find emergency response procedures.

Question 9 of 20

Placards must be at least how many inches on each side?

10.75 inches (273 mm)
5 inches
15 inches
20 inches

Correct. Placards are diamond-shaped, at least 250 mm (about 10.75 inches) on each side.

Question 10 of 20

Placards are required when:

Any amount of a Table 1 material is loaded, or 1,001+ lbs total of any combination of Table 2 materials
Any cargo is loaded
Only flammables are loaded
Only at the driver's discretion

Correct. Table 1 materials always require placards (any amount). Table 2 materials require placards when 1,001 pounds or more of any combination is loaded.

Question 11 of 20

A driver's responsibilities for hazmat include:

Refusing to accept improperly marked, labeled, or leaking shipments; placarding the vehicle; following routes; carrying the shipping paper; responding to incidents
Only signing the bill of lading
Only delivering on time
Only refueling

Correct. The driver verifies the shipment, placards if required, carries the documentation, follows routes and parking rules, and handles incidents per training.

Question 12 of 20

Subsidiary risk labels on a package indicate:

Additional hazards beyond the primary hazard
Just decoration
The price
The weight

Correct. Some materials have multiple hazards. The primary hazard is shown on the top-class label; subsidiary risks (e.g., toxic AND flammable) are shown on additional labels.

Question 13 of 20

Drivers of hazmat vehicles must avoid which of the following routes when alternatives exist?

Tunnels, narrow streets, and densely populated areas
Interstates
Highways
Rural routes

Correct. Avoid populated areas, narrow streets, tunnels, and other places where an incident would maximize risk. Follow state-designated hazmat routes.

Question 14 of 20

A driver of a hazmat-loaded vehicle must check the tires:

Once before the trip
At the start of the trip and every time the vehicle is parked
Only at fueling
Never

Correct. Hazmat drivers must check tires at the beginning and again each time the vehicle is parked. A flat or smoking tire must be addressed before continuing.

Question 15 of 20

When loading hazmat that requires segregation, the driver must:

Refuse to mix incompatible materials in the same vehicle, per the segregation table
Mix them anyway
Load whatever fits
Stack on top

Correct. The segregation table in 49 CFR §177.848 lists which classes cannot be loaded together. Refusing improperly mixed loads is the driver's responsibility.

Question 16 of 20

The Emergency Response Guidebook (ERG) is used to:

Plan routes
Look up the four-digit hazmat ID number to find emergency response procedures
Calculate fuel cost
Find truck stops

Correct. The ERG cross-references the four-digit ID number from the placard or shipping paper to a guide page with isolation distance, response procedures, and first aid.

Question 17 of 20

The Hazmat (H) endorsement requires:

Only a knowledge test
A knowledge test plus a TSA Threat Assessment background check
Just a fee
A skills test only

Correct. Hazmat applicants pass a knowledge test and complete the TSA Threat Assessment (HME), which involves fingerprints and an FBI background check.

Question 18 of 20

A driver may not carry hazmat aboard a vehicle without:

A current Hazmat (H) endorsement on the CDL
A green light
Two cell phones
A reflective vest

Correct. Hauling placardable hazmat requires the H endorsement, which includes a TSA Threat Assessment background check.

Question 19 of 20

A vehicle hauling explosives may not be parked within:

100 feet of an open fire, school, theater, or place where people gather
10 feet of any building
One block of a fire station
Any distance

Correct. Class 1 explosives have specific parking restrictions — at least 300 feet from open fires; never near schools, theaters, or places where people gather.

Question 20 of 20

After a hazmat incident, the driver should:

Notify the carrier and complete required reports
Drive home
Wait until the next trip to report
Throw away the shipping paper

Correct. Notify the carrier immediately. Federal incident reports may be required to PHMSA, depending on severity. Retain the shipping paper.

About the Tennessee Hazmat exam

Most states administer 30 Hazmat questions and require 80% to pass. The exam covers hazard classes, the shipping paper, placards and labels, loading and unloading, driving and parking rules, emergency response, and the Emergency Response Guidebook (ERG).

The Tennessee Department of Safety and Homeland Security Driver Services follows the federal CDL standards established by FMCSA. To earn the Hazmat credential, you must answer at least 80% of the questions correctly. Many candidates score lower the first time because the test pulls from a large pool — refreshing this page will give you a different mix of questions, drawn from the same authoritative source.

Want more practice? Try the full Hazmat question bank or browse all Tennessee CDL practice tests.