California Hazmat CDL Practice Test

This is a free 20-question practice test for the Hazmat portion of the California 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 California Department of Motor Vehicles 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 California.

Question 1 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 2 of 20

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 20

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 20

Hazard Class 8 is:

Flammable solids
Corrosives
Radioactive
Gases

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

Question 5 of 20

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 6 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 7 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 8 of 20

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 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 10 of 20

Hazard Class 3 is:

Flammable liquids
Explosives
Toxic substances
Radioactive

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

Question 11 of 20

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 12 of 20

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 13 of 20

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 14 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 15 of 20

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 16 of 20

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 17 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 18 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 19 of 20

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 20 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.

About the California 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 California Department of Motor Vehicles 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 California CDL practice tests.