CDL HazMat (H) Practice Test
Hazardous materials rules: placarding, loading, security plans, and emergency response. Requires a federal background check.
Loading the HazMat (H) question bank…
Last updated:
About the CDL HazMat (H) test
The CDL HazMat test earns the H endorsement, which you need to haul placarded amounts of hazardous materials such as explosives, gases, flammable liquids, corrosives, or radioactive goods. Beyond passing the written exam, you must clear a federal Transportation Security Administration background check before the endorsement is added to your license. The material comes from Section 9 of the federal Commercial Driver License Manual and rests on three goals: contain the product, communicate the risk, and transport it safely.
What the HazMat (H) test covers
- The hazard classes and the Hazardous Materials Table: the nine classes, proper shipping names, identification numbers, and packing groups.
- Shipping papers: how hazardous entries are marked, where the papers ride in the cab, and the emergency response phone number and Emergency Response Guidebook.
- Placarding: when placards are required, the four-placard rule, Table 1 versus Table 2 quantities, and the DANGEROUS placard.
- Loading and segregation: turning the engine off, careful handling, keeping poisons away from food, and separating materials that react together.
- Driving, routes, and security: tire checks, railroad crossings, tunnels and route plans, attendance and parking rules, security plans, and what to do at a leak or accident.
Common mistakes to avoid
The questions people miss most involve the placarding quantities and the emergency steps. Remember that Table 1 materials must be placarded in any amount, while Table 2 materials need placards only at 1,001 pounds or more aggregate gross weight, and that a placarded load carries four identical placards (front, rear, and both sides). On the road, many forget the tire rule (check within the first 50 miles, then every 2 hours or 100 miles) and the 300-foot parking distance for Division 1.1, 1.2, and 1.3 explosives. At a spill, never touch, walk through, or smell the material to identify it: use the shipping papers and the Emergency Response Guidebook instead.
How to study for it
Learn the nine hazard classes cold and drill the placarding thresholds until the numbers are automatic, since several questions test them directly. Keep the Emergency Response Guidebook steps and the shipping-paper location fresh, then run the full practice test and the exam simulator to rehearse under time. Start your TSA background check early, because it can take weeks and the endorsement will not be issued until it clears.
Other CDL tests
General Knowledge
Required for every CDL applicant (Class A, B, and C).
Air Brakes
Needed by nearly all Class A and most Class B drivers.
Combination Vehicles
Required for every Class A (tractor-trailer) applicant.
Passenger (P)
Bus, transit, and shuttle drivers.
School Bus (S)
School bus drivers (requires the Passenger endorsement first).
Tanker (N)
Drivers of liquid or gas tank vehicles.
CDL HazMat (H) test FAQ
How many questions are on the CDL HazMat test?
Most states use about a 30-question HazMat test with an 80% pass mark. Our practice and exam-simulator modes mirror the real format so you can rehearse the length and timing.
Do I need a background check for the HazMat endorsement?
Yes. Federal law requires a Transportation Security Administration security threat assessment, which includes fingerprinting and a background check, before the H endorsement is added to or renewed on your CDL. Apply early, since it can take several weeks.
When do hazardous materials have to be placarded?
Table 1 materials, such as certain explosives and poison inhalation hazards, must be placarded in any amount. Table 2 materials must be placarded once the total reaches 1,001 pounds or more of aggregate gross weight. When placards are required, you display four, on the front, rear, and both sides.
Is the HazMat test the same in every state?
In substance, yes. The content is federal, from Section 9 of the model CDL manual, so it is nearly identical across states, with only minor local differences in scheduling, fees, and route restrictions.