The hazmat endorsement test has 30 questions, and you need to answer at least 24 correctly to pass

The Hazmat (hazardous materials) endorsement test is a written exam administered by your state's Department of Motor Vehicles. It covers rules for transporting dangerous goods — explosives, flammables, poisons, radioactive materials, and other regulated substances. The test itself is straightforward in structure: 30 multiple-choice questions, 24 correct answers required to pass, and most states allow you 60 minutes to complete it.

This is a separate test from your CDL general knowledge and air brake exams. You take it after you pass those, and you can take it on the same day at most DMV locations. Some states allow you to take the hazmat test on a computer at the DMV; others use paper. Either way, the format and question count are the same across all states because the Federal Motor Carrier Safety Administration (FMCSA) sets the standard.

Key Takeaways

  • The hazmat test contains exactly 30 multiple-choice questions, and you must answer at least 24 correctly to pass.
  • You have approximately 60 minutes to complete the test, though the exact time limit may vary slightly by state.
  • The test covers nine hazard classes, shipping papers, placarding rules, emergency procedures, and vehicle safety requirements specific to hazmat transport.
  • You must pass the hazmat test before the DMV will add the hazmat endorsement to your CDL, even if you have already passed your general knowledge and air brake tests.
  • Most DMV locations allow you to take the hazmat test on the same day as your other CDL tests, but you pay a separate fee for the hazmat endorsement exam.

What the 30 questions cover

The hazmat test questions come from the Commercial Driver's License Manual published by your state, which itself follows FMCSA guidelines. The questions are not trick questions, but they are specific. You will see questions about the nine hazard classes (Class 1 through Class 9), how to identify them on shipping papers, what placards go on your vehicle, and what you must do in an emergency.

Common question topics include: which materials fall into which hazard class, how to read a shipping paper, when you must placard your vehicle, what placards look like and where they go, what you can and cannot do with certain materials in your vehicle, how to respond if there is a spill or leak, and vehicle safety rules (like no smoking, no idle time, proper ventilation). You will also see questions about your responsibilities as a driver, such as refusing to transport materials that are improperly labeled or packaged.

The questions test knowledge, not common sense. For example, you might be asked which hazard class includes oxidizers, or what the proper placard color is for a specific material. Memorizing the manual is the most reliable way to prepare.

How to prepare for the 30-question test

Your state's Commercial Driver's License Manual contains a hazmat section that covers everything on the test. Most states publish this manual online for free on the DMV website. Read the hazmat section carefully — it is usually 20 to 40 pages depending on the state — and take notes on the nine hazard classes, placard requirements, and emergency procedures.

After reading, use practice tests. Many states offer free practice tests on their DMV websites; others are available through third-party CDL study sites. Practice tests typically include 30 to 50 hazmat questions pulled from the same question bank the real test uses. Take the practice test under timed conditions (60 minutes) to get used to the pace. If you score below 24 correct, review the manual sections you missed and take another practice test.

Study groups or paid CDL prep courses can help if you learn better with instruction, but they are not required. The manual and practice tests are sufficient for most people who study consistently for one to two weeks before the test.

Passing score and retake rules

You must score at least 80 percent — that is, 24 out of 30 questions correct — to pass the hazmat endorsement test. If you score 23 or lower, you fail and must retake the test. Most states allow you to retake it the same day or within a few days, though some require a waiting period of 24 hours between attempts.

Each time you take the test, you pay the endorsement fee again. This fee varies by state but typically ranges from $10 to $50. If you fail multiple times, the cost adds up, so preparing thoroughly before your first attempt saves money and time.

Passing the hazmat test does not may provide that your hazmat endorsement will be added to your CDL when ready. You must also pass a background check run by the Transportation Security Administration (TSA). The TSA check can take several weeks, and if you fail it, your hazmat endorsement will not be issued even if you passed the written test. The DMV will tell you the status of your TSA check when you pass the written exam.

Hazmat test fees and timing

The cost of the hazmat endorsement test varies by state. Most states charge between $10 and $50 for the test itself. Some states bundle the hazmat test fee with the general CDL fee; others charge it separately. Check your state DMV website for the exact fee.

The test usually takes 30 to 45 minutes to complete, leaving you time within the 60-minute window. You can take the hazmat test on the same day as your CDL general knowledge test and air brake test at most DMV locations, but you will need to schedule all three or confirm that your local DMV allows same-day testing. Call ahead to ask about scheduling and whether you need to bring anything specific for the hazmat test (usually just your permit and ID).

What happens after you pass

Once you pass the 30-question hazmat test, the DMV records your passing score. You then enter the TSA background check process, which is separate from the written test. The TSA will review your criminal history, immigration status, and other factors to determine whether you are safe to transport hazardous materials. This check typically takes two to four weeks, though it can take longer if the TSA needs additional information from you.

If you pass the TSA check, the DMV will add the hazmat endorsement to your CDL. Your new CDL card will show the "H" endorsement code. If you fail the TSA check, you will not receive the endorsement, and the DMV will notify you of the reason (in general terms). You cannot retake the TSA check; if you are denied, you must wait at least one year before requesting reconsideration.

Frequently Asked Questions

Can I take the hazmat test without a CDL?

No. You must have a valid CDL permit or CDL before you can take the hazmat endorsement test. The hazmat test is an add-on to your CDL, not a standalone credential. You take it after you pass your general knowledge and air brake tests.

What if I fail the hazmat test?

You can retake it. Most states allow you to retake the test within a few days or even the same day, though some require a 24-hour waiting period. You pay the endorsement fee again each time you retake it. Study the manual more thoroughly before your next attempt, and use practice tests to identify weak areas.

Does the hazmat test have the same questions every time?

No. The DMV draws questions from a larger question bank, so each test is different. However, the topics and types of questions are the same. Studying the hazmat section of your state's CDL manual prepares you for any version of the test.

What if I pass the written test but fail the TSA background check?

Your passing score on the written test remains valid, but you will not receive the hazmat endorsement on your CDL. You can request reconsideration after one year. You do not need to retake the written test if your TSA denial is overturned.

How long is the hazmat endorsement good for?

The hazmat endorsement is valid for the same period as your CDL — typically five or eight years depending on your state. When you renew your CDL, you must renew the hazmat endorsement as well, which usually involves retaking the hazmat test and passing another TSA background check.