Oklahoma Hazardous Materials CDL Practice Test
Below are 25 exam-style questions for the Oklahoma Hazardous Materials CDL knowledge test, modeled on the FMCSA-aligned content used by the Oklahoma Department of Public Safety. 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.
- A A document describing all hazardous materials being carried
- B The train's schedule
- C The number of cars
- D The train's crew
- A During the trip if you stop
- B All of the above
- C Before leaving the loading site
- D In an emergency
- A Park near an open flame
- B Park near a fire
- C Park within 5 feet of a road
- D All of the above
- A Only at night
- B At 10, 100, and 200 feet from the vehicle
- C At 50 and 100 feet
- D Within 10 feet only
- A Proper shipping name, hazard class, ID number, and required emergency information
- B Color of packaging
- C Price only
- D Driver's name
- A Only sign and drive
- B Trust the shipper without checking
- C Wait for an inspector
- D Verify markings, labels, placards, papers, and securement before signing for it
- A No special handling
- B Only a special placard at night
- C Vehicle escort
- D Special handling, additional documentation, and route planning
- A Cargo securement straps
- B An expired permit or shipper certification missing
- C A medical card
- D A logbook
- A Only at the start and end
- B Once a week
- C Never; tires are the carrier's responsibility
- D At the start of each trip and each time they stop
- A Travel with a state escort
- B Drive only between 8 a.m. and 6 p.m.
- C Avoid Class A highways only
- D Have written instructions on what to do in case of accident or delay
- A Leave the truck and return when finished
- B Stay within 25 feet of the vehicle and have a clear view of it
- C Disconnect the bonding wire first
- D Hand off the unloading to the receiver
- A A placard for the trailer interior
- B A placard for a small load only
- C A placard for state-only highways
- D A placard for an additional hazard the material poses besides the primary hazard
- A Only on Class 1 explosives
- B Never
- C Any single placard
- D Two or more separate placards on a load that contains different hazard classes (Table 2 materials only)
- A UN or NA followed by four digits
- B A barcode only
- C A serial number
- D A state two-letter code
- A Containers can rub against each other
- B Cargo cannot shift, leak, or be exposed to ignition sources
- C Cargo blocks emergency exits
- D They can shift freely
- A A separate trailer license
- B X (combination of H and N for tank vehicles carrying hazardous materials)
- C A medical card upgrade
- D A pilot car
- 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
- A State and local routing
- B Federal rules (tunnels, bridges)
- C Carrier preference
- D All of the above
- A Cargo that may be harmful to aquatic life and requires special marking
- B Bulk shipments
- C Only liquids in port areas
- D Hazardous waste only
- A The receiver has paid
- B The driver has training
- C The shipper guarantees the load is properly classified, packaged, marked, labeled, and described per regulations
- D The carrier has insurance
- A All of the above
- B Carry shipping papers and ERG
- C Have current hazmat training
- D Have current TSA security threat assessment
- A Only at the start of the trip
- B When the brakes feel different
- C At each stop
- D Only at the destination
- A Within 50 feet of the crossing
- B Between 15 and 50 feet from the nearest rail
- C Only at night
- D Only when a train is approaching
- A Communicate the risk, contain the materials, and protect the public
- B Reduce fuel use
- C Provide tax revenue
- D Help drivers move faster
- A In a designated truck stop
- B In any rest area
- C Within 300 feet of a tunnel, bridge, or building used by the public, except for short rest stops
- D On a public street within 5 feet of the road
Study tips for the Oklahoma Hazardous Materials exam
The Hazardous Materials portion of the Oklahoma CDL exam is graded out of the bank of questions the Oklahoma Department of Public Safety draws from each year. While the exact bank is not published, every question is sourced from the Hazardous Materials chapter of the Oklahoma 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 Oklahoma 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 Oklahoma Department of Public Safety 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 Oklahoma 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 Oklahoma 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 Oklahoma Department of Public Safety office.
Already comfortable with this endorsement? Drill another: OK General Knowledge · OK Air Brakes · OK Combination Vehicles · OK Passenger · OK School Bus · OK Tank Vehicle · OK Doubles / Triples
New to the CDL process in Oklahoma? Read How to apply for a CDL in Oklahoma for the document checklist and step-by-step timeline.