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State DMVs (FMCSA rules, AAMVA CDL Manual)

Commercial Driver's License (CDL) Endorsement Knowledge Tests: Hazardous Materials (H) and Tank Vehicles (N)

The endorsement tests for hauling hazardous materials and liquids in bulk: placards, shipping papers, loading, parking, emergencies, surge, outage and rollover.

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QuestionsTypically Hazardous Materials 30 · Tank Vehicles 20 (counts vary by state)
Passing80% on each test, scored separately (49 CFR 383.135)
PrerequisitesA CDL or CLP with General Knowledge passed. Tank needs a Class A or B vehicle. Hazmat needs ELDT theory first and is typically 21+ for interstate driving
Security checkTSA Hazmat Threat Assessment: fingerprints and background check, $86.50 (less with a valid TWIC), good for up to 5 years
WhereAt your state DMV or driver licensing office, usually on a computer
FeeKnowledge-test and endorsement fees are set by your state. The TSA fee is separate
RenewalTo keep H, you retake the hazmat knowledge test and renew the TSA threat assessment

About the exam

The Hazardous Materials (H) endorsement lets a CDL holder haul placarded hazmat, and the Tank Vehicle (N) endorsement covers liquids or gases in tanks. Drivers who carry both get the combined X endorsement in most states. They're the endorsements fuel, chemical and gas haulers need. Each one takes a separate knowledge test at your state DMV, written to the hazmat and tank sections of the AAMVA-based CDL manual every state uses. Doubles/Triples, Passenger and School Bus are endorsements too, but this page doesn't cover them.

The Hazmat test typically has 30 questions and the Tank test 20, and you need 80% on each. Hazmat has more steps than any other endorsement. First-time applicants must finish Entry-Level Driver Training theory with a registered provider before taking the test, and pass a TSA security threat assessment with fingerprints before the state can issue the endorsement. You must re-qualify for it at every renewal.

Our practice follows the manual and the federal rules behind it: the intent of the regulations and who is responsible for what; the nine hazard classes; shipping papers, labels and placards, including the 1,001-pound rule and the materials that always need placards; loading, segregation and bulk packaging; driving, attendance and parking rules; and emergencies. The tank section covers inspection, high center of gravity, liquid surge, baffles and bulkheads, smooth-bore tanks, outage and safe handling.

How we track your progress

Every blueprint domain moves through five levels as you study:

  1. Not startedNo questions answered in this domain yet.
  2. Getting startedFirst questions answered — not enough yet to judge.
  3. DevelopingAt least 5 answered and 50% or better on your recent questions.
  4. ProficientAt least 15 answered and 70% or better on your recent questions.
  5. Exam readyAt least 25 answered, 80% or better recently, and holding up on hard questions.

The exam blueprint

AAMVA model CDL Manual Sections 8 and 9 (as republished in state CDL manuals) · 49 CFR Part 383 · PHMSA Hazardous Materials Regulations (49 CFR 171–180) — Hazardous Materials (typically 30) and Tank Vehicles (20), each scored separately with 80% to pass. Domain weights are QuizMe estimates based on typical question counts. Tap a domain to see its topics.

1 Intent of the Regulations and Responsibilities about 8% (est.) of the exam
Why the rules exist: contain, communicate, ensure safe driversShipper responsibilities: classify, package, mark, label, papersCarrier responsibilities: verify, refuse improper shipmentsDriver responsibilities: check, placard, transport, reportHazmat endorsement, training and the TSA threat assessmentThe Hazardous Materials Table and forbidden materials

16 practice questions in this domain so far

2 Hazard Classes and Communication (Papers, Labels, Placards) about 20% (est.) of the exam
The nine hazard classes and divisionsShipping paper description: ID number, name, class, packing groupIdentifying hazmat on mixed shipping papers (first, highlight, X, RQ)Where the driver keeps shipping papersPackage markings and labelsPlacard design and placement on all four sidesTable 1 materials: placard any amountTable 2 materials and the 1,001-pound ruleThe DANGEROUS placardEmergency response information and phone number

40 practice questions in this domain so far

3 Loading and Unloading about 10% (est.) of the exam
General loading rules: parking brake, no smoking, no hooksSecuring packages against movementCargo heaters and closed cargo spaceSegregation: materials that can't be loaded togetherExplosives (Class 1) loading precautionsCylinders, corrosives and poisons near foodRadioactive materials and the transport index

20 practice questions in this domain so far

4 Bulk Packaging about 6% (est.) of the exam
What counts as bulk packagingID numbers on placards or orange panelsCargo tank attendance during loading and unloading (25 feet)Closing manholes and valves before movingCargo tank markings and specification platesHazardous waste manifest

12 practice questions in this domain so far

5 Driving and Parking Rules about 10% (est.) of the exam
Railroad crossings: stop 15 to 50 feet before the railTunnels, bridges and hazmat route restrictionsRoute plans for explosives and radioactive materialsAttending a placarded vehicle (100 feet, clear view)Parking placarded vehicles and explosives (5 and 300 feet)No smoking, fueling with engine off, fire extinguisherChecking tires and dealing with leaksSafe havens

20 practice questions in this domain so far

6 Hazmat Emergencies about 6% (est.) of the exam
Emergency Response Guidebook (ERG)First steps: secure the area, keep people away, upwindFires and when to fight themLeaks and spills: don't touch, don't move the vehicle furtherReporting: carrier, National Response Center, CHEMTRECClass-specific responses (explosives, gases, corrosives, radioactive)

12 practice questions in this domain so far

7 Tank Vehicle Basics and Inspection about 16% (est.) of the exam
When the Tank (N) endorsement is requiredTypes of tank vehicles and their cargoInspecting tanks for leaks, dents and damageValves, pipes, hoses and connectionsManhole covers, vents and gasketsEmergency shut-off systems and groundingSpecial purpose equipment and vapor recovery

32 practice questions in this domain so far

8 Driving Tank Vehicles about 24% (est.) of the exam
High center of gravity and rollover riskLiquid surge and smooth starts and stopsBulkheads and weight distributionBaffled tanks: front-to-back vs. side-to-side surgeSmooth-bore (unbaffled) tanksOutage: why tanks are never filled completelyHow much to load: density and legal weightCurves, stopping distance and skids

48 practice questions in this domain so far

What you get when you access this exam

Free with your QuizMe account.

Questions built on the CDL manual

Every question is original, written to the hazmat and tank sections of the AAMVA-based manual your state uses, and tagged to one of 8 areas.

Hints that teach the rule

Reveal the rule behind a question when you're stuck: which classes always need placards, where shipping papers go, why tanks need outage. Every answer comes with a plain-language explanation.

Adaptive practice

Questions steer toward your weakest areas, weighted by how much each test counts, and get harder as you get stronger.

Timed practice tests

Take Hazmat and Tank back to back (50 questions) with a pacing indicator, a full review and a percent score against the 80% pass mark.

Flashcards, case simulations and guides

100 flashcards, 6 unfolding hazmat and tanker cases where every decision changes what happens next, and interactive illustrated guides to placards, shipping papers and tank design.

Progress for every area

Each area moves from Not started to Getting started, Developing, Proficient and Exam ready, so you know exactly what to study next.

Test at home or at a center

Endorsement knowledge tests are given by your state's driver licensing agency. For Hazmat, start the TSA threat assessment early, since it can take 45 days or more.

At your state DMV or licensing office

  • Take the Hazmat and Tank tests on a computer, one at a time, usually alongside your other CDL knowledge tests or as an add-on to an existing CDL.
  • Bring your license or CLP and the documents your state lists. Hazmat applicants usually also need proof of citizenship or lawful permanent residence.
  • Results usually appear as soon as you finish. You need 80% on each test.
  • Hazmat can't go on a learner's permit. Tank can go on a CLP, but only for driving empty tanks.

Before you go (Hazmat)

  • Complete ELDT hazmat theory training with a provider on FMCSA's Training Provider Registry. The provider reports it before you can test.
  • Apply for the TSA Hazmat Threat Assessment online, then give fingerprints at an enrollment center. Some states, such as Texas, New York and Pennsylvania, handle it through the DMV.
  • TSA recommends applying at least 60 days before you need the endorsement, including for renewals.
  • Download your state's CDL manual and study the hazmat and tank vehicle sections. Many states call them Sections 9 and 8.

Exam-day game plan

How to walk in ready — and how to pace 50 questions in 50 minutes (Hazmat 30 + Tank 20; the real tests are taken separately).

Pacing checkpoints

Hit these and you finish with time to revisit your flagged questions. Our timed practice exams run at this same pace.

13questions0:13
25questions0:25
38questions0:38
50questions0:50

The week before

  • Know the nine hazard classes and their placards by sight.
  • Learn Table 1 (placard any amount) and the 1,001-pound rule for everything else.
  • Memorize the distances: papers within reach, attend within 100 feet, cargo-tank loading within 25 feet, no smoking within 25 feet, park 5 feet off the road, explosives 300 feet from bridges, tunnels and buildings, rail stops 15 to 50 feet.
  • For Tank, be able to explain surge, baffles, smooth bore, bulkheads and outage in your own words.

Test day

  • Bring every document your state lists, plus anything TSA or the DMV sent about your threat assessment.
  • Get there early. Endorsement tests can be added to your other knowledge tests on the same visit in most states.
  • Eat something and go easy on caffeine.

During the tests

  • Hazmat questions turn on exact wording: 'must', 'never', 'any amount', '1,001 pounds or more'.
  • Ask yourself what the driver has to do, as opposed to the shipper or carrier.
  • When in doubt, choose the answer that keeps the material contained and people away from it.
  • Watch for EXCEPT and NOT.

Keep your head

  • A few nerves sharpen focus. If you freeze, take three slow breaths and reread the question.
  • You need 24 of 30 on Hazmat and 16 of 20 on Tank, so a few misses won't sink you.
  • Each test is scored separately. If you miss one, you usually retake only that test.

Keeping your endorsements

  • CDL renewal periods are set by your state, usually 4 to 8 years.
  • To keep the Hazmat endorsement, you must pass the hazmat knowledge test again and complete a new TSA threat assessment. The threat assessment typically has to be redone every 5 years, sooner if your state's license cycle is shorter.
  • Start the TSA renewal at least 60 days before your endorsement expires so it doesn't lapse.
  • The Tank endorsement normally renews with your CDL without retesting. Check your state's rules.

Official sources and further reading

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200 questions and scenarios across the blueprint — and growing.

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QuizMe and thinQtank Learning are not affiliated with or endorsed by any state DMV or driver licensing agency, FMCSA, PHMSA, TSA or AAMVA. All questions are original and written to the AAMVA-based CDL manual and federal hazmat rules, but states add their own rules and question pools, so always study your state's CDL manual and confirm requirements with your state and TSA before you test.