Idaho Hazmat CDL Practice Test

This is a free 20-question practice test for the Hazmat portion of the Idaho 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 Idaho Transportation Department Division 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 Idaho.

Question 1 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 2 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 3 of 20

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 4 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 5 of 20

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 6 of 20

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 7 of 20

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 8 of 20

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 9 of 20

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 10 of 20

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 11 of 20

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 12 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 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 "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 15 of 20

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 16 of 20

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 17 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 18 of 20

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 19 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 20 of 20

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.

About the Idaho 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 Idaho Transportation Department Division 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 Idaho CDL practice tests.