How to Pass the CDL Hazmat Endorsement Test
How to pass the CDL hazmat (H) endorsement knowledge test: the federal 80% passing score, what 49 CFR 383.121 says the test covers, ELDT and TSA threat assessment requirements, and a study plan.
Problem this solves
This guide solves the next-step problem for CDL Hazmat candidates: it explains what matters, then gives you a direct way to test that knowledge with practice questions instead of guessing what to study next.
The Short Answer
To pass the CDL hazmat (H) endorsement knowledge test, answer at least 80% of the questions correctly, the federal minimum in 49 CFR 383.135. Study your state's CDL manual hazmat section, finish entry-level driver training from a registered provider if this is your first H endorsement, and start the TSA security threat assessment early.
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CDL Hazmat · Question 1 of 5
Which endorsement must a CDL driver have to transport hazardous materials in amounts requiring placards?
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Three Requirements, Not One Test
Getting an H endorsement takes more than a written test. Under federal rules: 1. Training. Since February 7, 2022, a driver seeking a hazardous materials (H) endorsement for the first time must complete the training for that endorsement from a provider listed on FMCSA's Training Provider Registry (49 CFR 380.609). 2. Knowledge test. The H endorsement requires a knowledge test, with no skills test (49 CFR 383.93). 3. Security threat assessment. A state may not issue, renew, upgrade or transfer an H endorsement unless the Transportation Security Administration has determined the driver does not pose a security risk, or the driver holds a valid TWIC (49 CFR 383.141). The H endorsement cannot go on a commercial learner's permit; the only endorsements allowed on a CLP are passenger, school bus and tank vehicle (49 CFR 383.93).
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What the Test Covers
49 CFR 383.121 lists the knowledge a hazmat applicant must have, drawn from 49 CFR parts 171, 172, 173, 177, 178 and 397: - Hazardous materials regulations: the hazardous materials table, shipping papers, marking, labeling, placarding, packaging, definitions and preparation, other regulated material, reporting accidents, and tunnels and railroad crossings. - Handling: forbidden materials and packages, loading and unloading, cargo segregation, buses and hazardous materials, attendance of vehicles, parking, routes, cargo tanks and safe havens. - Emergency equipment: protecting the public, precautions for equipment used in fires and during loading and unloading, and equipment for tank vehicles. - Emergency response: precautions for different types of accidents, driving near a fire, smoking rules, emergency procedures and special requirements for Class 1.1 and 1.2 explosives. - Operating practices and procedures not otherwise specified. In practice, placarding, shipping papers, segregation and attendance rules produce most of the tricky questions, because they turn on exact quantities and exceptions.
Format, Scoring and Fees
- Passing score: at least 80% correct on each knowledge test (49 CFR 383.135). - Number of questions: Not published federally. Each state sets its own test; check your state CDL manual. - Time limit: Not published federally; set by your state. - State test and endorsement fees: Not published federally; set by your state driver licensing agency. - TSA threat assessment fee: Not published as one national figure. TSA sets it in Federal Register notices and the amount depends on whether your state uses TSA's enrollment provider; check your state's HME page. - Renewal: states must renew H endorsements every 5 years or less so that drivers go through the TSA security screening at least every 5 years (49 CFR 383.141).
A Practical Study Plan
1. Start the paperwork first. Book your ELDT hazmat theory course and begin the TSA application early; the security check can take longer than the studying. 2. Read your state's CDL manual hazmat section end to end. Most state manuals follow the same model, and it is the document your state test is written from. 3. Master the placard tables. The placarding rules are in 49 CFR 172.504: Table 1 lists the materials that need placards in any amount, and Table 2 lists those that depend on quantity. Learn both tables and their exceptions. Our hazmat placard guide is a quick way to drill this. 4. Learn shipping paper rules. Where the papers go, what entries are required, and how hazmat entries are distinguished from other items. 5. Memorise the segregation and attendance rules. These are short lists with exceptions, which makes them ideal test material. 6. Practise until you clear 80% with margin. Take timed sets and review every miss against the manual section it came from.
Mistakes to Avoid
- Waiting to start the TSA threat assessment until after you pass. Your state cannot issue the endorsement without it. - Skipping ELDT because you already hold a CDL. The training applies to a first-time H endorsement. - Studying from another state's manual or an old edition. Question count and test rules vary by state. - Memorising placard names without the quantity rules and exceptions. - Aiming for exactly 80%. Leave yourself a buffer.
Exam-Day Tips
- Bring what your state licensing office requires, typically your current CDL or CLP and proof of identity and residency; check the list before you go. - Read each question for quantities and exceptions; many wrong answers are right in general but wrong for the amount given. - Answer every question. Unanswered questions do not help you reach 80%.
Keep Practising
Drill placarding, shipping papers and emergency response with the CDL hazmat exam prep question bank, and check your baseline with the free hazmat practice test. Practice scores do not predict a state result; use them to find weak topics.
Sources
Checked 2026-10-24. - eCFR, 49 CFR 383.135, passing knowledge and skills tests - eCFR, 49 CFR 383.121, requirements for hazardous materials endorsement - eCFR, 49 CFR 383.93, endorsements - eCFR, 49 CFR 383.141, TSA approval of hazardous materials endorsements - eCFR, 49 CFR 172.504, general placarding requirements - eCFR, 49 CFR 380.609, entry-level driver training requirements - FMCSA, Training Provider Registry launch - Federal Register, TSA HME fee notice (2024)
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