Hazmat CDL Practice Test

The Hazmat (H) endorsement is required for any commercial driver who transports hazardous materials in placardable quantities. It is the most regulated endorsement: in addition to passing a knowledge test, you must complete a TSA Threat Assessment background check (HME) before the endorsement is issued.

Start Practice Test ↓ Study Guide

What's on the 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).

Topics covered

Hazard classes 1 through 9 and divisions
Hazardous Materials Table and proper shipping name
Shipping papers, manifests, and emergency contact info
Placards: when required, where placed, four-sided rule
Markings and labels
Loading and unloading: floors, valves, dunnage, segregation
Driving and parking: routes, tunnels, attended parking
Smoking, refueling, and parking near fires
Communication rules at railroad crossings
Reporting accidents and incidents
Hazardous Materials Regulations (HMR) compliance
Cargo tank specifications (overview)
Routes that prohibit hazardous materials

Who needs this endorsement

Drivers transporting hazardous materials in quantities that require the vehicle to display placards. The endorsement requires a TSA fingerprint background check that takes 30 to 60 days; renew it before the five-year expiration to avoid a license downgrade.

All 68 Hazmat Practice Questions

Click any answer to reveal the correct one and the explanation. Take a state-specific 20-question randomized round on any of the state pages.

Question 1 of 68 · #224

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 2 of 68 · #225

The Hazardous Materials Table (HMT) lists:

Only flammable liquids
Each hazardous material with its proper shipping name, hazard class, ID number, packing group, and required label
Only items shipped by air
Only items shipped by truck

Correct. The HMT in 49 CFR §172.101 lists every hazardous material with its proper shipping name, hazard class, identification number, packing group, label requirements, and special provisions.

Question 3 of 68 · #226

How many hazard classes are there?

Three
Five
Nine
Twelve

Correct. There are nine hazard classes: 1 explosives, 2 gases, 3 flammable liquids, 4 flammable solids, 5 oxidizers and organic peroxides, 6 toxic and infectious, 7 radioactive, 8 corrosive, 9 miscellaneous.

Question 4 of 68 · #227

Hazard Class 1 is:

Flammable liquids
Explosives
Corrosives
Radioactive materials

Correct. Class 1 covers explosives, divided into divisions 1.1 through 1.6 by mass-explosion and projection hazard.

Question 5 of 68 · #228

Hazard Class 3 is:

Flammable liquids
Explosives
Toxic substances
Radioactive

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

Question 6 of 68 · #229

Hazard Class 8 is:

Flammable solids
Corrosives
Radioactive
Gases

Correct. Class 8 is corrosive materials — sulfuric acid, sodium hydroxide, hydrochloric acid, etc.

Question 7 of 68 · #230

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 8 of 68 · #231

Placards must be displayed on:

One side
Two sides
Three sides
All four sides of the vehicle

Correct. Placards are displayed on all four sides of the vehicle — front, back, and both sides.

Question 9 of 68 · #232

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 68 · #233

The shipping paper for hazmat must include:

Only the destination
Proper shipping name, hazard class, ID number with UN/NA prefix, packing group, total quantity, and emergency contact
Only the weight
Only the carrier name

Correct. A complete shipping paper includes proper shipping name, hazard class or division, UN/NA ID number, packing group (where applicable), total quantity and unit, and a 24-hour emergency contact.

Question 11 of 68 · #234

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 12 of 68 · #235

Who is responsible for proper hazmat packaging and labeling?

The shipper
The driver
The carrier
The consignee

Correct. The shipper packages, labels, and certifies the materials. The carrier and driver verify and refuse non-compliant shipments.

Question 13 of 68 · #236

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 14 of 68 · #237

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 15 of 68 · #238

When refueling a hazmat-loaded vehicle:

Leave the engine running
Turn off the engine, do not smoke, and someone must control the fueling process
Smoke if you are far enough away
It does not matter

Correct. Engine off, no smoking within 25 feet of the vehicle being fueled, and someone must be in control of the fueling at the nozzle.

Question 16 of 68 · #239

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 17 of 68 · #240

Where can a hazmat-placarded vehicle never be parked?

On private property
Within 5 feet of the traveled portion of a roadway, except briefly for vehicle operation
Anywhere
At a truck stop

Correct. Never park within 5 feet of the traveled portion of a road. Avoid populated areas, near open fires, and near places where people congregate.

Question 18 of 68 · #241

Class 1.1, 1.2, or 1.3 explosives must be parked:

Anywhere
In an attended location with a qualified person within 100 feet, awake and able to see the vehicle
At a school
At a gas station

Correct. Division 1.1, 1.2, and 1.3 explosives, and Division 2.3 or 6.1 PIH cargo, must have an attended-vehicle (qualified person within 100 feet, awake, able to see the vehicle).

Question 19 of 68 · #242

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 68 · #243

When loading a vehicle with hazardous materials, you should:

Set the parking brake, chock the wheels, turn off the engine
Leave the engine running
Smoke if outside the cab
Skip the brake check

Correct. Set the parking brake, chock wheels of cargo tank vehicles, and shut off the engine before loading or unloading flammables.

Question 21 of 68 · #244

You may use a flame to check for hazmat leaks:

When you have a respirator
Never — never use any flame near hazmat
Only at night
Only with permission

Correct. Never use a flame to check anything near hazmat. Use a flashlight or other intrinsically safe light.

Question 22 of 68 · #245

You discover a leak in a Class 3 (flammable liquid) shipment. You should:

Continue driving until you find a safe place
Stop, secure the area, notify emergency services, do not transfer cargo on the road, do not move the vehicle further than necessary
Drive faster to deliver the load
Open the placards

Correct. Stop in a safe location, secure the area, call 911, and notify your dispatcher. Do not transfer cargo by the side of the road.

Question 23 of 68 · #246

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 24 of 68 · #247

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 25 of 68 · #248

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.

Question 26 of 68 · #249

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 27 of 68 · #250

A vehicle that has been transporting hazmat may need to be:

Decontaminated and re-placarded as required after unloading
Painted
Sold
Inspected by USCG

Correct. After unloading, the vehicle may need decontamination depending on the cargo. Placards may need to be removed unless residue still requires them.

Question 28 of 68 · #251

Inhalation hazard placards (Division 6.1 PIH or Division 2.3) require:

Smaller placards
Subsidiary "INHALATION HAZARD" placards in addition to the primary placard
No placards
Only one placard

Correct. PIH (Poison Inhalation Hazard) materials require a primary hazard-class placard plus an "INHALATION HAZARD" subsidiary placard.

Question 29 of 68 · #252

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 30 of 68 · #253

A hazmat driver must complete which special training?

General awareness, function-specific, safety, security awareness, and in-depth security if a security plan is required
Forklift training
Basic first aid only
Defensive driving only

Correct. PHMSA requires general awareness, function-specific, safety, security awareness, and in-depth security training (when a security plan applies). Carriers document and re-train every three years.

Question 31 of 68 · #254

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 32 of 68 · #255

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 33 of 68 · #256

A leaking package of hazmat:

Should be immediately driven to the destination
Must not be transported; secure and report
Should be wrapped in plastic
Should be ignored

Correct. Never transport a leaking package. Secure the area, report to the carrier, contact emergency services if the leak poses immediate danger.

Question 34 of 68 · #257

The 24-hour emergency response phone number on the shipping paper:

Is optional
Must be provided by the shipper and monitored 24 hours per day
Is the driver's personal phone
Is for billing

Correct. The 24-hour emergency contact must be a person knowledgeable about the materials, available 24/7. Many shippers contract CHEMTREC or similar.

Question 35 of 68 · #258

A driver of a placarded hazmat vehicle approaching a tunnel that prohibits hazmat must:

Use a designated alternate route
Drive through quickly
Cover the placards
Go around the prohibition sign

Correct. Many tunnels prohibit certain placarded vehicles. Use the designated alternate route. Bypassing the prohibition is a serious violation.

Question 36 of 68 · #259

Electrical equipment in cargo areas of vehicles transporting Class 3 (flammable) liquids must be:

Disconnected
Spark-free or explosion-proof to prevent ignition
Painted red
Made of plastic

Correct. Wiring and electrical fittings in flammable-liquid loading areas must be designed to prevent ignition — spark-free, sealed, or explosion-proof.

Question 37 of 68 · #260

A driver hauling hazmat must immediately notify the carrier if:

Any incident occurs that involves spillage, fire, contamination, injury, evacuation, or substantial property damage
Only if there is property damage
Only if police arrive
Only if cargo arrives late

Correct. Any spill, fire, contamination, injury, evacuation, or substantial damage triggers immediate carrier notification. The carrier files required federal reports.

Question 38 of 68 · #261

When tarping hazmat cargo, you must:

Cover the placards
Leave placards visible at all times
Tarp only at night
Use only red tarps

Correct. Placards must remain visible. Tarps and decorations may not block them.

Question 39 of 68 · #262

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 40 of 68 · #263

When a hazmat shipment crosses international borders:

Documentation may need to comply with both US and Canadian/Mexican regulations
No special documentation is needed
Only US regulations apply
Only foreign regulations apply

Correct. Cross-border hazmat may require documentation in compliance with both jurisdictions, plus customs paperwork.

Question 41 of 68 · #264

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 42 of 68 · #265

The H endorsement TSA background check is required to be renewed every:

Year
3 years
5 years
10 years

Correct. The TSA HME is good for five years. Renew before expiration to avoid losing the endorsement.

Question 43 of 68 · #266

A hazmat carrier with hazmat cargo must conduct security awareness training:

Once at hire
Once every 3 years for each driver
Annually
Never

Correct. PHMSA requires re-training every three years, including security awareness and the carrier's in-depth security plan if applicable.

Question 44 of 68 · #267

The shipper must certify on the shipping paper that:

The shipment complies with HMR (Hazardous Materials Regulations)
The shipment is heavy
The driver is qualified
The truck is empty

Correct. The shipper signs a certification that the shipment is properly described, packaged, marked, labeled, and complies with HMR.

Question 45 of 68 · #268

When transporting hazmat, you must check the cargo every:

Mile
100 miles
150 miles or 3 hours, plus changes of duty status
500 miles

Correct. Federal cargo securement: check at the start, then every 150 miles or 3 hours of driving, plus every change of duty status.

Question 46 of 68 · #269

Hazmat marking on a non-bulk package includes:

Proper shipping name and UN/NA number
Just the weight
Just the destination
Color only

Correct. Non-bulk markings include the proper shipping name and UN/NA identification number, plus consignor/consignee information.

Question 47 of 68 · #270

A "bulk packaging" generally refers to:

Packaging holding less than 119 gallons of liquid
Packaging holding more than 119 gallons of liquid, more than 882 lbs solid, or more than 1,000 lbs of gas
Anything in a box
Plastic only

Correct. Bulk packaging exceeds 119 gallons (liquid), 882 lbs (solid), or 1,000 lbs (gas). Bulk packaging requires markings, the four-digit ID number on each side and end, and additional driver-training requirements.

Question 48 of 68 · #271

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 49 of 68 · #272

When you stop a hazmat-placarded vehicle at the side of the road, you must place reflective triangles:

Within 10 minutes of stopping
Immediately, but never use flares with Division 1.1, 1.2, 1.3 explosives, oxidizers, or flammable cargo
Only if dark
Only if other vehicles are present

Correct. Place warning devices within 10 minutes. Never use flares with explosives, flammable cargo, or oxidizers — use reflective triangles or red lanterns.

Question 50 of 68 · #273

You must not transport a vehicle that:

Has Class 1 explosives and is leaking, or any vehicle whose hazmat is leaking
Has fresh paint
Is over weight by 50 lbs
Is white

Correct. Never transport a leaking hazmat package. Secure the scene, notify authorities and the carrier, follow the carrier's instructions on disposition.

Question 51 of 68 · #274

When you place placards on a vehicle, the placard ID number (when applicable) must:

Be displayed on each side and end of bulk packagings or on placards or orange panels
Not be shown
Be in red ink only
Be a phone number

Correct. Bulk packagings and certain shipments require the four-digit UN/NA number on each side and end of the package, on the placard, or on an orange panel.

Question 52 of 68 · #275

A driver must understand the hazmat security plan:

Only managers do
Only when it is required for the carrier and the materials being transported, then driver in-depth security training is required
Never
Only on request

Correct. When a security plan is required (Division 1.1, 1.2, 1.3, certain quantities of toxic-by-inhalation, etc.), drivers receive in-depth security training and a copy or summary of the plan.

Question 53 of 68 · #276

When loading or unloading cargo tanks of flammable liquid, the driver must:

Stay alert and within 25 feet of the vehicle, with a clear view
Leave the area
Smoke
Run the engine at high RPM

Correct. During cargo-tank flammable-liquid loading or unloading, the driver must remain attentive and within 25 feet of the vehicle with an unobstructed view.

Question 54 of 68 · #277

Mixing certain hazmat in one shipment is prohibited because:

Of cost
They may react dangerously together; the segregation table specifies prohibitions
It is too heavy
Of regulations on cargo color

Correct. Some classes react dangerously when mixed (e.g., acids with cyanides, oxidizers with flammables). The segregation table prohibits these mixtures.

Question 55 of 68 · #278

Hazmat drivers must report any change of:

Address to the licensing agency
Daily route
Diet
Vehicle paint color

Correct. Address changes must be reported to the state licensing agency in line with state CDL requirements; some states require reporting within 30 days.

Question 56 of 68 · #279

In a hazmat fire, you should:

Try to extinguish all fires regardless of size
Determine the materials involved using the shipping paper and ERG; only fight small fires that you can safely extinguish
Run
Pour water on every fire

Correct. Identify materials and consult the ERG. Only fight small fires that you can safely extinguish; large fires require professional response. Some materials react violently with water.

Question 57 of 68 · #280

You should never smoke or carry an open flame near hazmat that is:

Class 1 (explosives), Class 2.1 (flammable gas), Class 3 (flammable liquid), or oxidizers (Class 5.1)
Any class
Class 9
Class 6

Correct. Smoking or open flames are dangerous near explosives, flammable gases, flammable liquids, and oxidizers. The 25-foot rule applies during loading.

Question 58 of 68 · #281

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 59 of 68 · #282

Bulk packaging of certain corrosives requires:

No special markings
Display of the proper shipping name on each side and the four-digit ID number on each side and end
Only one placard
Painted red

Correct. Bulk packaging of corrosives, like other hazmat, requires shipping name on the sides and ID-number marking on each side and end.

Question 60 of 68 · #283

When carrying hazmat through a state or local jurisdiction with route restrictions, you must:

Comply with the restrictions
Choose the shortest route
Take the highway always
Disregard local rules

Correct. State and local hazmat route restrictions are enforceable. Plan routes that comply with restrictions and avoid prohibited tunnels and bridges.

Question 61 of 68 · #284

When unloading flammable liquids from a cargo tank, the driver should:

Bond and ground the tank to the receiving container to prevent static-spark ignition
Disconnect the ground
Smoke
Run the engine

Correct. Bonding and grounding equalizes electrical potential between the tank and receiving container, preventing static-spark ignition during product transfer.

Question 62 of 68 · #285

Carrying a hazmat shipment without the required shipping paper:

Is allowed if you remember the cargo
Is a violation; the shipping paper must be present and accessible
Is allowed if you have a phone
Has no consequence

Correct. Operating without proper shipping papers is a regulatory violation and dangerous — emergency responders rely on the paper to identify materials.

Question 63 of 68 · #286

A "DANGEROUS" placard may be used:

Instead of multiple Table 2 placards when 1,001+ lbs of two or more Table 2 materials are loaded
For any cargo
For non-hazmat
For hazmat below 100 lbs

Correct. When more than two Table 2 materials are aboard with combined weight over 1,001 lbs (none over 2,205 lbs at one stop), a single DANGEROUS placard may substitute.

Question 64 of 68 · #287

During loading of cargo tanks of flammable liquid, the driver must remain:

Alert, within 25 feet of the cargo tank, with a clear view, ready to handle emergencies
Far away
In the cab with the engine running
At lunch

Correct. Driver must stay within 25 feet of the cargo tank during loading or unloading of flammable liquid and remain ready to act in emergency.

Question 65 of 68 · #288

You must notify your dispatcher and the carrier whenever:

You receive any traffic ticket
Any hazmat incident occurs
Anytime you stop
Anytime you fuel

Correct. Hazmat incidents — spillage, fire, contamination, injury, evacuation, or property damage — require immediate carrier notification.

Question 66 of 68 · #289

Class 7 (Radioactive) materials require:

Special placards depending on the radiation level (I, II, or III), maintaining a Transport Index, and limits on aggregate radioactivity in a vehicle
No special handling
Only one placard
No documentation

Correct. Class 7 materials use Roman-numeral category labels (RADIOACTIVE I, II, III), placarded based on aggregate Transport Index, and have specific transport limits.

Question 67 of 68 · #290

The "Wetline" rule for cargo tanks of flammable liquid:

Limits the amount of flammable liquid that may be left in product piping during transit
Allows leaks
Bans tankers
Permits unlimited residue

Correct. Wetline regulations restrict residual flammable liquid in cargo-tank product piping during transportation, due to ignition risk if a piping line is breached.

Question 68 of 68 · #291

You should keep the hazmat shipping paper:

Identifiable and within reach of the driver, marked with a tab or kept on top of other papers
Hidden
In the trailer
Folded inside the manual

Correct. Hazmat shipping papers must be identifiable to emergency responders — tabbed or kept on top of other paperwork, in the seat or door pouch when the driver is out.