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Missouri Hazardous Materials CDL Practice Test

Below are 25 exam-style questions for the Missouri Hazardous Materials CDL knowledge test, modeled on the FMCSA-aligned content used by the Missouri Department of Revenue. Try to answer each question on your own before reading the answer key directly under it. The questions and answer choices are shuffled deterministically per state and endorsement, so the order will stay the same on repeat visits — that lets you genuinely measure your improvement.

Heads up: this is a study tool, not a graded exam. Cover the answer with your hand or a sheet of paper for an honest practice run, then re-read the explanations for any questions you missed. Aim for 22 out of 25 or better, three times in a row, before scheduling the real exam.
Question 1 of 25
In a hazmat fire, you should:
  • A Drive the vehicle to a safe place
  • B Stay upwind, evacuate the area, and let trained responders handle it
  • C Try to put it out with water
  • D Open the cargo doors to ventilate
Correct answer: B
Untrained personnel should not fight hazmat fires; evacuate, isolate, and notify professional responders.
Question 2 of 25
A common hazardous material identification number begins with:
  • A A barcode only
  • B UN or NA followed by four digits
  • C A state two-letter code
  • D A serial number
Correct answer: B
UN (United Nations) or NA (North America) plus four digits identifies the material in the Hazardous Materials Table and the ERG.
Question 3 of 25
A "compatibility" group is used for:
  • A Drivers, not cargo
  • B All hazmat materials
  • C Cargo tank vehicles only
  • D Class 1 explosives, to determine which can be loaded together
Correct answer: D
Compatibility groups (A through S) are used in classifying explosives.
Question 4 of 25
When you stop with a placarded vehicle on the side of the road, you must place reflective triangles:
  • A At 50 and 100 feet
  • B Only at night
  • C Within 10 feet only
  • D At 10, 100, and 200 feet from the vehicle
Correct answer: D
Standard triangle placement applies to all CMVs, including placarded ones.
Question 5 of 25
A driver must inspect hazmat shipping papers for:
  • A Price only
  • B Proper shipping name, hazard class, ID number, and required emergency information
  • C Color of packaging
  • D Driver's name
Correct answer: B
Shipping papers must be complete and correct before transport.
Question 6 of 25
Hazardous materials are classified into how many hazard classes?
  • A Twelve
  • B Seven
  • C Nine
  • D Five
Correct answer: C
There are nine hazard classes, from explosives (Class 1) to miscellaneous dangerous goods (Class 9).
Question 7 of 25
Loose hazmat packages can:
  • A Cause a leak or spill if the package is damaged
  • B All of the above
  • C Strike emergency exits
  • D Move and obstruct visibility
Correct answer: B
All three risks make securement essential.
Question 8 of 25
A "consist" of a train means:
  • A A document describing all hazardous materials being carried
  • B The number of cars
  • C The train's schedule
  • D The train's crew
Correct answer: A
Train consist documents are the rail equivalent of a hazmat shipping paper, listing what is on board.
Question 9 of 25
A driver who discovers a leak in a hazmat container should:
  • A Continue and report at the next stop
  • B Stop, isolate the area, notify emergency services and the carrier
  • C Open the container to inspect
  • D Drive to the destination quickly
Correct answer: B
Stop immediately, get people away, call emergency services, and notify the carrier per emergency procedures.
Question 10 of 25
A driver may not transport hazardous materials with:
  • A Cargo securement straps
  • B A medical card
  • C A logbook
  • D An expired permit or shipper certification missing
Correct answer: D
Without proper paperwork or current permits, the load cannot move legally.
Question 11 of 25
A driver may NOT carry hazmat in a:
  • A Truck designed for the specific class
  • B Vehicle in compliance with HMR
  • C Properly placarded trailer
  • D Vehicle without working brake lights or in unsafe condition
Correct answer: D
Vehicle must be in safe operating condition; defective lights, brakes, or other equipment make the load illegal.
Question 12 of 25
Hazmat shipping papers must be:
  • A Mailed to the destination
  • B Within reach of the driver while seated and within reach when the driver is out of the cab
  • C Stored in the trailer
  • D Filed in the cab's glove box
Correct answer: B
Driver's door pocket or driver's seat — easy to find quickly in an emergency.
Question 13 of 25
When carrying hazmat, you must check tires:
  • A When the brakes feel different
  • B Only at the destination
  • C At each stop
  • D Only at the start of the trip
Correct answer: C
Tire health is critical with placarded loads; check at each stop.
Question 14 of 25
Hazmat loads should be loaded so:
  • A Containers can rub against each other
  • B They can shift freely
  • C Cargo blocks emergency exits
  • D Cargo cannot shift, leak, or be exposed to ignition sources
Correct answer: D
Securement is critical to preventing leaks, friction sparks, and damage in transit.
Question 15 of 25
How many placards are required for most placarded loads?
  • A One
  • B Four (one on each side and one on each end)
  • C Two
  • D Six
Correct answer: B
A typical placarded load shows four placards — left, right, front, and rear of the vehicle.
Question 16 of 25
A driver who has a hazmat endorsement must:
  • A All of the above
  • B Renew the TSA assessment periodically
  • C Pass a TSA security threat assessment including fingerprinting
  • D Notify the carrier of any incident
Correct answer: A
Hazmat is the only CDL endorsement that includes a federal background check, with renewal cycles.
Question 17 of 25
A driver of a placarded vehicle must:
  • A Avoid weigh stations
  • B Have a written route plan if required by the shipper or by federal/state rules
  • C Drive at night only
  • D Take the most direct route regardless of restrictions
Correct answer: B
Hazmat routes are often regulated; some loads require an approved written route plan.
Question 18 of 25
Some hazmat loads require a special endorsement on top of the H endorsement:
  • A X (combination of H and N for tank vehicles carrying hazardous materials)
  • B A medical card upgrade
  • C A separate trailer license
  • D A pilot car
Correct answer: A
X combines Hazmat (H) and Tank (N) for drivers who haul hazardous materials in tank vehicles.
Question 19 of 25
Cargo tank trucks must be inspected:
  • A Once per year by federal officials
  • B Before each trip and at every stop
  • C When the tank is full
  • D Annually only
Correct answer: B
Tanks must be inspected for leaks, valves, and integrity before and during the trip.
Question 20 of 25
The shipper certification on a hazmat shipping paper means:
  • A The shipper guarantees the load is properly classified, packaged, marked, labeled, and described per regulations
  • B The driver has training
  • C The carrier has insurance
  • D The receiver has paid
Correct answer: A
The shipper certifies HMR compliance; the carrier and driver verify and transport.
Question 21 of 25
During the trip, hazmat drivers must inspect tires:
  • A At the start of each trip and each time they stop
  • B Once a week
  • C Never; tires are the carrier's responsibility
  • D Only at the start and end
Correct answer: A
Tires can heat up and fail more quickly with heavy loads; check at every stop.
Question 22 of 25
Hazardous materials drivers must avoid:
  • A Tunnels marked as prohibited for hazmat
  • B All of the above
  • C Routes prohibited for hazmat
  • D Driving over a railroad-highway grade crossing without stopping (most placarded loads)
Correct answer: B
Most placarded loads must stop at rail crossings, avoid prohibited tunnels, and follow specified route restrictions.
Question 23 of 25
A load of hazardous materials may not be parked:
  • A Within 300 feet of a tunnel, bridge, or building used by the public, except for short rest stops
  • B In a designated truck stop
  • C On a public street within 5 feet of the road
  • D In any rest area
Correct answer: A
Parking restrictions for placarded vehicles include distances from open flames, residences, schools, hospitals, and other places.
Question 24 of 25
Placards must be displayed on a vehicle when it is carrying:
  • A Only liquids
  • B Bulk quantities or any amount of certain Table 1 materials
  • C Only at night
  • D Any quantity of any hazardous material
Correct answer: B
Table 1 materials require placards in any quantity; Table 2 materials require placards only above 1,001 lbs aggregate.
Question 25 of 25
A bulk packaging is:
  • A A pallet
  • B One that has more than 119 gallons capacity (liquids) or more than 882 lbs (solids)
  • C Any package over 1 lb
  • D Cardboard boxes only
Correct answer: B
Federal definitions specify thresholds for bulk packaging that trigger additional requirements.

Study tips for the Missouri Hazardous Materials exam

The Hazardous Materials portion of the Missouri CDL exam is graded out of the bank of questions the Missouri Department of Revenue draws from each year. While the exact bank is not published, every question is sourced from the Hazardous Materials chapter of the Missouri CDL handbook, which itself is derived from the FMCSA Model Commercial Driver's License Manual. That means studying our practice tests, reading the corresponding handbook chapter, and re-reading the parts you got wrong is genuinely the most efficient route to a first-time pass.

Most successful applicants follow a simple cycle: take the practice test cold, write down every question you missed, open the matching chapter of the official Missouri handbook, re-read the section that contains the right answer, then re-take the practice test 24 to 48 hours later. The 24-hour delay matters — sleep is when your brain commits new information to long-term memory, and CDL knowledge questions reward that kind of consolidated learning rather than cramming.

Pay particular attention to questions that include qualifier words like always, never, only, primary, or most. CDL test writers love to flip the right answer with a single qualifier. When two answer choices look almost identical, pay attention to the verb (is it must, should, or may?) and to any numbers (14 days, 100 air miles, 8 hours, 70/8 split). On endorsement tests in particular, watch for trick framing where a true statement about a different endorsement is offered as the "correct" answer to a question that is actually about Hazardous Materials.

Test-day logistics matter too. Bring photo ID, your Social Security card or birth certificate, your medical examiner's certificate (DOT card), and proof of state residency if you haven't already submitted those documents. The Missouri Department of Revenue will not let you sit for the knowledge exam without your documentation, and most offices charge an additional fee for re-attempts. Arrive early — the wait at most CDL testing offices runs 30 to 60 minutes — and silence your phone before the exam begins.

Finally, keep your General Knowledge fundamentals sharp even when you're focused on the Hazardous Materials exam. Many states administer multiple knowledge tests in a single sitting, and questions on weight definitions (GVWR, GCWR, GAWR), stopping distance, and the pre-trip inspection routine show up across endorsements. If you're unsure on the basics, sit a fresh Missouri General Knowledge practice test before scheduling the real exam.

Next steps

Missed more than four questions? Re-read the Hazardous Materials study guide and the matching chapter in the official Missouri CDL handbook. Then come back and re-take the test. Once you can score 22 of 25 or higher on three runs in a row, you're in good shape to schedule the real exam at your local Missouri Department of Revenue office.

Already comfortable with this endorsement? Drill another: MO General Knowledge · MO Air Brakes · MO Combination Vehicles · MO Passenger · MO School Bus · MO Tank Vehicle · MO Doubles / Triples

New to the CDL process in Missouri? Read How to apply for a CDL in Missouri for the document checklist and step-by-step timeline.