Free CDL Practice Tests · All 50 States + DC · Updated 2026 Official handbooks · CDL pay & outlook
MD · H Endorsement

Maryland Hazardous Materials CDL Practice Test

Below are 25 exam-style questions for the Maryland Hazardous Materials CDL knowledge test, modeled on the FMCSA-aligned content used by the Maryland Motor Vehicle Administration. 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
A driver must inspect hazmat shipping papers for:
  • A Color of packaging
  • B Proper shipping name, hazard class, ID number, and required emergency information
  • C Price only
  • D Driver's name
Correct answer: B
Shipping papers must be complete and correct before transport.
Question 2 of 25
Hazmat loads should be loaded so:
  • A Containers can rub against each other
  • B They can shift freely
  • C Cargo cannot shift, leak, or be exposed to ignition sources
  • D Cargo blocks emergency exits
Correct answer: C
Securement is critical to preventing leaks, friction sparks, and damage in transit.
Question 3 of 25
A driver of a placarded vehicle who is involved in an accident must:
  • A Notify the carrier immediately
  • B All of the above
  • C Notify the National Response Center if the load is leaking or hazmat-related
  • D Provide the responding officers with the shipping papers and ERG
Correct answer: B
All three responsibilities apply in a hazmat accident.
Question 4 of 25
Cargo heaters used during transport of explosives:
  • A Must be operated by the receiver
  • B Must meet special standards or be turned off
  • C May only be used after 6 p.m.
  • D Are unrestricted
Correct answer: B
Special restrictions apply to cargo heaters with most flammable and explosive loads.
Question 5 of 25
When you cannot find an entry for a material in the Hazardous Materials Table:
  • A Skip the placards
  • B Use a generic placard
  • C Refuse the load and notify the carrier — the shipper must use a proper shipping name
  • D Use the closest entry
Correct answer: C
Materials must use a proper shipping name from the table; otherwise, the load cannot be transported.
Question 6 of 25
You should review your shipping papers and the ERG:
  • A In an emergency
  • B All of the above
  • C Before leaving the loading site
  • D During the trip if you stop
Correct answer: B
Familiarity with the load and the response guide is essential at every step.
Question 7 of 25
The Emergency Response Guidebook (ERG) is:
  • A Carried in the trailer
  • B Mailed to the receiver
  • C Only required for explosives
  • D Carried in the cab and used by responders to look up immediate response information for hazmat
Correct answer: D
The orange ERG is a roadside response reference. Drivers and responders use it to look up emergency procedures.
Question 8 of 25
A "marine pollutant" is:
  • A Hazardous waste only
  • B Cargo that may be harmful to aquatic life and requires special marking
  • C Only liquids in port areas
  • D Bulk shipments
Correct answer: B
Marine pollutants require additional markings to alert responders to environmental risk near water.
Question 9 of 25
A load of hazardous materials may not be parked:
  • A In any rest area
  • B In a designated truck stop
  • 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
Correct answer: C
Parking restrictions for placarded vehicles include distances from open flames, residences, schools, hospitals, and other places.
Question 10 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 Filed in the cab's glove box
  • D Stored in the trailer
Correct answer: B
Driver's door pocket or driver's seat — easy to find quickly in an emergency.
Question 11 of 25
Cargo tanks loaded with flammable liquids must be:
  • A Inspected once a year only
  • B Loaded only by the receiver
  • C Loaded only at night
  • D Bonded and grounded during loading and unloading
Correct answer: D
Bonding equalizes electrical potential to prevent static spark; grounding sends static to earth.
Question 12 of 25
When you discover a hazmat error after starting the trip:
  • A Stop and notify the carrier and shipper before continuing
  • B Continue and report later
  • C Hide the error
  • D Drive faster to compensate
Correct answer: A
Errors are corrected before continuing; do not assume that minor errors are acceptable.
Question 13 of 25
A vehicle with a leaking hazmat container should:
  • A Be left where it is, the area isolated, and the carrier and emergency services notified
  • B Be driven to the destination
  • C Be moved to a remote area immediately
  • D Be unloaded by the driver alone
Correct answer: A
Do not drive a leaking hazmat vehicle further than necessary; isolate and call professionals.
Question 14 of 25
When carrying hazmat, you must check tires:
  • A Only at the start of the trip
  • B Only at the destination
  • C When the brakes feel different
  • D At each stop
Correct answer: D
Tire health is critical with placarded loads; check at each stop.
Question 15 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 pilot car
  • D A separate trailer license
Correct answer: A
X combines Hazmat (H) and Tank (N) for drivers who haul hazardous materials in tank vehicles.
Question 16 of 25
You may transport hazardous materials with:
  • A Pickups only
  • B Vehicles whose driver and equipment meet all federal safety requirements
  • C Any vehicle
  • D Vehicles older than 5 years
Correct answer: B
Equipment must meet HMR specifications, and drivers must be properly licensed and trained.
Question 17 of 25
During the trip, hazmat drivers must inspect tires:
  • A Never; tires are the carrier's responsibility
  • B Once a week
  • C At the start of each trip and each time they stop
  • D Only at the start and end
Correct answer: C
Tires can heat up and fail more quickly with heavy loads; check at every stop.
Question 18 of 25
Hazardous materials regulations are intended to:
  • A Reduce fuel use
  • B Provide tax revenue
  • C Communicate the risk, contain the materials, and protect the public
  • D Help drivers move faster
Correct answer: C
The Hazardous Materials Regulations focus on communicating the risk (placards, papers), containment, and public safety.
Question 19 of 25
Drivers carrying hazmat must:
  • A Have current hazmat training
  • B Have current TSA security threat assessment
  • C Carry shipping papers and ERG
  • D All of the above
Correct answer: D
All three are required for placarded hazmat operations.
Question 20 of 25
A driver who has a hazmat endorsement must:
  • A Renew the TSA assessment periodically
  • B Pass a TSA security threat assessment including fingerprinting
  • C All of the above
  • D Notify the carrier of any incident
Correct answer: C
Hazmat is the only CDL endorsement that includes a federal background check, with renewal cycles.
Question 21 of 25
You must keep hazmat shipping papers separate from other documents:
  • A No — mix them in with other paperwork
  • B Only on long trips
  • C Only if the receiver requests it
  • D Yes — they should be readily identifiable for emergency responders
Correct answer: D
Shipping papers are tabbed or kept on top of stack for quick identification.
Question 22 of 25
When refueling a placarded vehicle:
  • A The driver must be at the fueling control
  • B No smoking within 25 feet
  • C All of the above
  • D Engine must be off
Correct answer: C
All three rules apply during refueling of placarded loads.
Question 23 of 25
When you accept a hazmat load, you should:
  • A Verify markings, labels, placards, papers, and securement before signing for it
  • B Trust the shipper without checking
  • C Wait for an inspector
  • D Only sign and drive
Correct answer: A
Driver verification at acceptance protects you from carrying improperly prepared loads.
Question 24 of 25
After loading hazardous materials, the driver should:
  • A Verify shipping papers, placards, and securement before leaving the loading site
  • B Take a break first
  • C Allow shipper to drive away
  • D Drive to the destination immediately
Correct answer: A
Final verification at the loading site catches paperwork or placard errors before they become roadside violations.
Question 25 of 25
When you stop with a placarded vehicle on the side of the road, you must place reflective triangles:
  • A Within 10 feet only
  • B At 10, 100, and 200 feet from the vehicle
  • C At 50 and 100 feet
  • D Only at night
Correct answer: B
Standard triangle placement applies to all CMVs, including placarded ones.

Study tips for the Maryland Hazardous Materials exam

The Hazardous Materials portion of the Maryland CDL exam is graded out of the bank of questions the Maryland Motor Vehicle Administration draws from each year. While the exact bank is not published, every question is sourced from the Hazardous Materials chapter of the Maryland 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 Maryland 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 Maryland Motor Vehicle Administration 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 Maryland 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 Maryland 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 Maryland Motor Vehicle Administration office.

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

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